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1 SOLUCIONARIO CUADERNO DE TRABAJO ACTIVIDADES CAP 01 ÁNGULO TRIGONOMÉTRICO 01 5p 8 = 5 8 (180°) = 112,5° = 112°30'00'' Clave C 02 30x + 10(9°) = 270° – 90° x = 3° Clave B 03 x2 – 3x – 10 9 = x2 – 2x – 4 10 10x2 – 30x – 100 = 9x2 – 18x – 36 x2 – 12 – 64 = 0 x – 16 = 0 x –16 x +4 ⇒ x = 4 Clave D 04 3C + 2S = 240 ; 10S = 9C 15C + 10S = 240(5) 15C + 9C = 240(5) ⇒ C = 50 Clave D 05 S + 9C = 330 ; 9C = 10S S + 10S = 330 ⇒ S = 30 R = p 6 Clave C 06 10 k3 – 1 19 = 9 k3 + 1 19 10k3 – 10 19 = 9k3 + 9 19 k3 = 19 19 ⇒ k = 1 S = 1 – 1 19 = 18 19 ⇒ 18 19 p = 180R R = p 190 Clave C 07 1 2S – 1 3C = 1 20 ; S 9 = C 10 ⇒ 5 9C – 3 9C = 1 20 ⇒ C = 40 9 Luego: 18 19 p = 200R R = p 45 Clave B 08 nC + nS = 3800 R p n 200R p + 180R p n = 3800 R p ⇒ 380n = 3800 n = 10 Clave C 09 (10k)2 + (9k)2 = 2(10k)3 – 5(9k)(10k)2 + 4(9k)2(10k) – (9k)3 – 2(9k)(10k) ⇒ 181 = 11k – 180 ⇒ k = 361 11 C = 10 361 11 = 3610 11 Clave C 10 a° → (a – 3) 180° → 120 ⇒ 120a = 180(a – 3) 2a = 3a – 9 a = 9 a – 3 = 6 Clave B CUADERNO DE TRABAJO 01 b = 2°4'5'' b = 2(3600'') + 4(60'') + 5'' b = 7200'' + 240'' + 5'' b = 7445'' Clave B 02 5x – 3 = 6x – 9 x = 6 (5x – 3)° (6x – 9)° Clave C 03 Siendo S C = 9 10 7x + 2 8x = 9 10 x = 10 S = (7x + 2) = 72 × p 180 El ángulo es: 2p rad 5 Clave B 04 Se cumple: C + S + R = 2S + R + 4 C = S + 4 10k = 9k + 4 k = 4 ⇒ C = 40 R = 40p 200 = p 5 ∴ El ángulo es p 5 rad Clave E 05 10k(9k)2 + (9k)3 = (10k – 9k)2 810k3 + 729k3 = k2 k = 1 1539 R = 9k × p 180 = 9 × 1 1539 × p 180 R = p 30780 Clave A 06 • n2 1 19 n2 – = 9 10 10n2 – 10 19 = 9n2 n2 = 10 19 C = 10 19 • R = 10 19 × p 200 = p 380 Clave E 07 • xy° zw' = 50g50m • Pero 50g× 9° 10g = 45° 50m = 1 2 g × 9° 10g×60' 1° = 27' xy° zw' = 45°27' q = 4 + 5 2 + 7 = 1 Clave A 08 180R p + 200R p + R = 95 + p 4 380R p + R = 380 + p 4 R 380 + p p = 380 + p 4 R = p 4 Clave B 09 4R 9p pR + Rp = 5 2R + 3p = 5 Rp 2R – 5 Rp + 3p = 0 R = 9p 4 R = p 2 R –3 p R –1 p 9p 4 = 405° Clave B 10 7N 5° = 63N x x = 45° x = 45°×p rad 180° = p 4 rad Clave C TAREA 01 230° + x = 40° x = – 190° 02 40ng + (24n)° = 90° 40ng × 9° 10g + (24n)° = 90° 36n + 24n = 90 n = 3 2 03 prad 32 × 180° prad = 45° 8 prad 32 = 5° 5 8 = 5° 300' 8 prad 32 = 5° 75' 2 = 5° 37' 30'' a + b – c = 12 ↓ ↓ ↓ a b c TRIGONOMETRÍA 5° EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 2 04 • 9k – 13 8 = 10k – 2 12 108k – 156 = 80k – 16 28k = 140 k = 5 • S = 9(5) = 45 • 45 – 13 8 = x 2 4 x = 4 REFORZANDO 01 –(2 – 2x)° + 5xg 9° 10g = 180° – 2 + 2x + 9x 2 = 180 x = 28 Clave D 02 Se tiene que a = 27k y b = 50k, entonces: H = 27 27k+100k 27k + 42 = 127+42 = 13 Clave D 03 Tenemos 10S = 9C 10 1080 60 = = 9(3x + 5) 20 = 3x + 5 x = 5 Luego β = 20g + (11(5))g = 75g Entonces 75g = 75 p 200 rad = 3p 8 rad Clave C 04 Tenemos S = 9k, C = 10k y R = pk 20 162k2 – 10k = 100k2 + 18k 62k = 28 k = 14 31 Luego, C = 10 14 31 = 140 31 Clave A 05 El ángulo C: 180° – (6t)° > 0 180 > 6t t < 30 Para que C tome su menor medida t = 29, Luego: C = 180° – 174° = 6° = 6p 180 rad = p 30 rad Clave E 06 ap 15 rad + 30(a + b)° + 100 3 (a – b)g = 180° 12a + 30(a + b) + 30(a – b) = 180 72a = 180 a = 5 2 Luego, A = 5 2 p 15 = p 6 rad Clave B 07 Tenemos 10S = 9C 10 18x – 18 p = 9 10x + 30 p 90 2x – 2 p = 90 x + 3 p x = 5 p Luego, S = 18 x – 1 p = 18 5 p – 1 p = 18 4 p Por lo tanto, R = p 180 (18) 4 p = 4 10 = 2 5 rad Clave B 08 b – a = 2300 b = 2300 + a Luego: a 27 = 2300 + a 50 23a = 27 × 2300 a = 2700 Por consiguiente, 2700 60 ° = 45° = p 4 rad Clave D 09 • a°a' + agam = 61a 60 ° + 9 10 101a 100 ° = 5777a 300 ° = 11,554° 5777a = 3(11554) a = 6 Luego, agam = 6g6m = 606 100 ° R = p 200 606 100 = p 303 10000 = 0,0303p rad Clave E 10 Como 5a + 4β = – 21° (1) 4a – 5β = 180° (2) Resolviendo simultáneamente, las ecua- ciones (1) y (2) se tiene que: a = 15° β = –24° Luego: –a – β = –15° + 24° = 9° = 9 p 180 = p 20 rad Clave D 11 Se tienen que: S3 + SC + S C3 + SC + S = 9 10 S C S2 + C + 1 C2 + S + 1 = 9 10 S2 + C + 1 = C2 + S + 1 0 = 19k2 – k k = 1 19 Rrad = p 20 1 19 rad = p 380 rad Clave C 12 Tenemos S = 9k, C = 10k y R = pk 20 Entonces: 27 k3 + 27 k3 + 27 k3 = 3 64 3(27) k3 = 3 64 k3 = 27(64) k = 12 R = p 20 (12) = 3p 5 rad Clave D 13 a = (2a – 1)prad = (a – 1)° (2a – 1)p p = a – 1 180 2a – 1 = a – 1 180 360a – 180 = a – 1 359a + 1 = 180 Luego β = 180g = 9p 10 rad Clave C 14 (100,405)g = 100g + (0,4)g + (0,005)g ((0,4)g = 40m, (0,005)g = 50s (100,405)g = 100g40m50s a = 100, b = 40 y c = 50 Por lo tanto, γ mide 60°45' ≅ 27p 80 rad Clave C 15 a = 162000'' = 45° = 50g y β = 3p 25 rad = 24g a + β = 74g, luego Com(a + β) = 26g Clave D ACTIVIDADES CAP 02 LONGITUD DE ARCO 01 L = 40° × p 180° 18 ⇒ 4p m Clave B 02 11 = q(14) ⇒ q = 11 14 = 1 4 22 7 = 1 4 p Clave B 03 2 r = 4 r + 3 ⇒ r + 3 = 2r ⇒ r = 3 Clave C 04 x a = 3x b ⇒ a b = 1 3 Clave E 05 2p 5 = L 7 ⇒ L = 14p 5 Clave A 06 x = 2(4) ⇒ x = 8 y = 3(4) ⇒ y = 12 y – x = 4 Clave B 07 nv = 80p 2p (4) ⇒ nv = 10 Clave C 08 q = 2 r = 4 r + 4 ⇒ r + 4 = 2r ⇒ r = 4 Clave C 09 Propiedad: x = a(a) + b(b) a + b x = a2 + b2 a + b Clave A 10 L = 10(2pa) = p 3 (a2 + 62a – 3) EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 3 60a = a2 + 62a – 3 3 = a2 + 2a Clave A CUADERNO DE TRABAJO 01 L = qR 2p = 14×q q = 2p 14 = p 7 Clave C 02 20 x = 40 x + 30 = 20 30 x = 30 Clave A 03 L2 r = L 2r = L1 3r L1 + L2 4r = L 2r 16p 4 = L 2 L = 8p Clave B 04 OB = 2OD OB = 2r y OD = r L2 2r = L1 r L2 – L1 r = L2 2r A B C D r r L1 L2 10 r = L2 2r L2 = 20 Clave B 05 a 180 = b 200 = q p 3bq = 720 p a 3b 3b a 3 10 9 a q = 720 p a q = 216 p Clave B 06 • a + b = p 2 (1) • L1 – L2 = 2 R(a – b) = 2 (2) • a b = 2 (3) De (1) y (3): b = p 6 a = p 3 De (2): R p 6 = 2 R = 12 p Clave A 07 5L r = 8L a + r = 9L 18 r = 10 y a = 6 Pero a + b + r = 18 b = 2 8L 9L5L a a b b r r 18 M = a – b = 6 – 2 = 4 Clave B 08 OC = 132 – 52 OC = 12 L1 = 12q L2 = 13q K = L1 L2 = 12 13 Clave B 09 Long EC = long BE = 4 p 6 = 2p 3 Perímetro: A B E C 4 44 D 30°30° 60° 60° 4p 3 + 4 = 4 p 3 1 + Clave A 10 5 = D1 2p(2) D1 = 20p D1 D2 2 2 · 6 2 = D2 2p(6) D2 = 24p D = D1 + D2 + 4 3 D = 44p + 4 3 = 4(11p + 3) Clave A TAREA 01 • L = qR 56 = q4 q = 14 02 q = 140°× p 180° rad = 7p 9 L = qR L = 7p 9 ⋅R L R = 7p 9 03 04 • 4L x = 5L x + 2 = 4L x = L 2 x = 8 REFORZANDO 01 L = qR 33 = 3R R = 11 Clave D 02 q = 30° = p 6 R = 6 L = qR = p 6 ⋅ 6 = p m Clave A03 4 R + 3 = 2 R = 2 3 R = 3 Clave C 04 L = 110 cm R = 70 cm L = qR 110 = q ⋅ 70 3n + 1 = 25 n = 8 q = n + 1 n = 9 8 n n n + 1q q = 11 7 = 1 2 22 7 q = p 2 rad Clave D 05 L1 r = L2 2r = L3 3r L1 1 = L2 2 = L3 3 L1 = q, L2 = 2q, L3 = 3q k = (1 + 4 + 9)q2 q(3q – q) = 7 Clave E 06 qg × 9° 10g = 9q° 10 L1 = 9q° 10 (3R) L2 = q°(R) k = L1 L2 = qR 27qR 10 = 10 27 Clave B 07 c = b r = a r + x c = a – b x x = (a – b)c–1 Clave C 08 Perímetro: = 1 p + 3 ⋅ p 6 + 1 p + 3 ⋅ p 6 + 1 p + 3 = 1 3 Clave D 09 Clave B 10 Como los sectores circulares tienen el mismo radio y la región sombreada tiene un arco de 7p 6 Perímetro = 7p R 6 Clave E 11 nv = Lc 2p(1) 20 = Lc 2p Lc = 40p y L = 40p 4 + 2 L = 10p +2 Clave D 12 q = S r = C 2R + r q = C – S 2R 2 R 2 R 2 R 120°12 0° 120° 1 3 ⋅ V 1 3 ⋅ V L = 2pR + 6R L = 2R(p + 3) 1 3 ⋅ V 60° 60° 30° 60° 60° 60° r 2R 2R r S Cq EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 4 q = 20R p 2R = 10 p Clave B 13 z r = y a + r = x a + b + r y – z a = x – y b yb – zb = ax – ay ay + by = ax + bz M = ay + by ax + bz = 1 Clave B 14 30° 60° 60° L1L1 R R R R RRR L2 L3 L1 = p 3 R L2 = p 6 R L3 = R 3 – R Piden: 2L1 + L2 + L3 2 p 3 R + p 6 R + R 3 = R 5p 6 + 3 Clave B 15 2(R1 + R2 + R3) = 100 R1 + R2 + R3 = 50 ∑ Longitudes = p(R1 + R2 + R3) = 50p Clave E CUADERNO DE TRABAJO CAP 03 ÁREA DEL SECTOR CIRCULAR 01 S = 1 2 120g p 200g (8)2 S = 19,2p m2 Clave A 02 Propiedad: S b2 = 3S n2 ⇒ n = 3b Longitud de arco: A O D C n b b Sq 2S a 3 n B q( 3b) = a 3 q = a b Clave B r r a a b b yz x R3 R2 R1 03 L + 9 2 2 = 21 ⇒ L = 12 A O D C L r r 2 2 9 q 21u2 B 9 r = 12 r + 2 ⇒ r = 6 Perímetro: 2p 2p= 6 + 9 + 6 = 21 u Clave E 04 S x2 = 3S y2 = 6S 42 ⇒ x 3 = 2 2 y = 2 2 A O F E C D 4 S 3S 2S y x B y + x 3 = 4 2 Clave C 05 Propiedad: x = 3(2) + 18(1) 1 + 2 ⇒ x = 8 E O B 1 1 2 2 A M N 18 S3 r r x F a Área: S = 3 + 8 2 (1) S = 11/2 cm2 Clave E 06 Propiedad: S1 r2 = S1 + S2 (2r)2 C O B A r r r r S1 S2 D S2 S1 = 3 Clave C 07 1 2 2p 5 r2 = 45p ⇒ r = 15 2p 5 45p r r 1 2 2p 5 – a (30)2 = 30p 2p 5 – a 2r 2r 30p a = p 3 Clave B 08 S = (2R)2 2 p 3 – sen60° S = 2R2 p 3 – 3 2 S = R2(2p – 3 3)/3 30° 60° 2R S R R BQ P O A 30° Clave C 09 P O q Q 10q10 10 10 108 6 6 ⇒ 2p(6) ⇒ 10q = 2p(6) q = 6p 5 Clave C 10 16(w + x + z) = 5(9x) w + x + z = 45 16 x 5na 2 3nb 2 = 25x 9 45 16x D C A Q P 2n 2n 3n 3n R 16x ab 16w 9w 9x 9z 16z S O a b = 16 27 Clave B CUADERNO DE TRABAJO 01 Área = 11×14 2 14 14 11 Área = 77 Clave A 02 Área = 2 + 4 2 3 = 9 Clave E 03 3x + 1 = (2x – 1)(x – 1) x = 3 Luego: S = 1 2 (2)(5)2 = 25 cm2 Clave B 04 Sabemos: 2r + L = 20 + p y L = p 10 r 2r + p 10 r = 20 + p r = 10 20g L r S = 1 2 × p 10 ×(10)2 = 5p cm2 Clave C 05 1) qa = 1; 2) q(a + b) = 2a; 3) q(3a + b) = b De 1) y 2): a + b a = 2a a + b = 2a2 b = 2a2 – a De 1) y 3): 3a + b a = b 2a + 2a2 a = 2a2 – a 2a2 – 3a – 2 = 0 (a – 2)(2a + 1) = 0 a = 2, b = 6, q = 1 2 rad Área del sector circular COD = 1 2 ×1 2 ×82 = 16 m2 Clave E 06 9 Long AB = 16 + 9 45 Long AB = 27 Clave C 07 6 9 = 9 + SX 10 6 3 = 9 + SX 10 9 cm2 6 A BD C SXO 10 9 + SX = 25 SX = 16 Clave B EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 5 08 S1 = p 2 R2 – S S2 = q 2 (4R)2 – S RR 2R S2S1 S S1 = S2 q 2 (4R)2 = p 2 R2 q = p 16 Clave C 09 LAB = p 3 R # vueltas = p 3 ×R 2p(0,2) = 45 R = 54 S = 1 2 ×p 3 ×(54)2 = 486p B O A R R Clave D 10 r2 + b2 = (a – b)2 ⇒ r2 = a(a – 2b) S = 1 2 qa(a – 2b) S = qa 2 (a – 2b) a –b a b b r Clave A TAREA 01 q = 2rad L = 4 A = 42 2(2) = 4 02 A = 16 ⋅ 18 2 ⇒ A = 144 m2 03 • Perímetro: 10 + 5q = 100 = q = 2 • Área: S = (2)52 2 = 25 5 5 5qq S 04 •A = 2 + 3 2 ⋅ 4 = 10 m2 3 m2 m A 4 m 4 m REFORZANDO 01 • 1 2 p 12 (4R2) = 21p 5 R2 = 126 5 • Área = 1 2 5p 12 ⋅ R2 Área = 1 2 5p 12 ⋅ 126 5 = 21p 4 Clave D 2R p/12 R A O D B CR R 5p 12 02 • 4l = pr ⇒ r = 4l p S = 1 2 (l) 4l p = 8 p l = 2 Clave D 03 4 O A C B4 a q • 4q = 29p 30 q = 29p 120 • 4 2(q – a) 2 = p 3 8 29p 120 – a = p 3 29p 120 – a = p 24 a = p 5 rad Clave D 04 • S1 (2L)2 = S1 + S2 (3L)2 S1 4 = S2 5 S1 = 4 5 (S2) = 4 5 p 2 = 2p 5 S1 r2 = S1 + S2 (r + 4)2 2p 5 r2 = 2p 5 + p 2 (r + 4)2 r = 8 cm Clave C 05 Clave E 06 • S = 25 L = (3x + 4) q = (4 – x) r = ? (3x + 4)2 2(4 – x) = 25 x = 2 L = qr r = L q = 3x + 4 4 – x r = 5 m Clave E 07 q = p 12 r = 12 S = 122 2 p 12 = 6p O B A 12 12 12 C p 4 p 3 p 3 – p4 = p 12 Clave D 08 q = 50g prad 200g = p 4 S = 2p r = ? S = qr2 2 2p = p 8 ⋅ r2 r = 4 O A r r r S M N l B 4l p Si L1 = 2L L2 = 3L 4 r S1 2L 3LS2 • Long AB S = 4p S + 3S Long AB = 2p S 3SO A C D B 4p L = 2p(4) L = 8p L p = 8p p = 8 Clave C 09 • a 2 S = (a + x)2 2S = (a + x + y)2 3S a 1 = a + x 2 = a + x + y 3 a + x + y = 3a 3S = (a + x + y) 2 ⋅ a = a 2 3 2 Clave D 10 • S1 r2 = S1 + S2 (2r)2 S1 1 = S1 + S2 4 S1 1 = S2 3 S2 S1 = 3 Clave A 11 A F E D r r120° 60° B C O • El ángulo del área sombreada es: 360° – 120° = 240° = 4p 3 1 2 4p 3 r2 = 8p 3 r = 2 • Por triángulo notable: OC = 2r ∧ OF = 3r Área sector AOB = 1 2 p 3 ⋅ (3r)2 = 6p Clave A 12 • La longitud del arco AB es: r p 2 = 9p r = 18 • La longitud del arco OC mas la longitud del arco AC es igual a la longi- tud de AB: 9p Perímetro es: 9p + 18 = 9(2 + p) Clave E S E F C D A B O S S a a x y r r r r S1 S2 A B C O r r r r p 3 p 3 p 6 EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 6 13 Asomb = 4p – A 2 – A 4 – A A = 3(22) 3 4 = 3 3 A 2 = 22 2 p 3 – 2 2 3 4 = 2p 3 – 3 A 4 = 42 2 p 3 – 4 2 3 4 = 8p 3 – 4 3 A sombreada: 4p – 10p 3 – 2 3 = 2p 3 + 2 3 Clave C 14 • S1 (2r)2 = S1 + S2 (5r)2 = S1 + S2 + S3 (6r)2 S1 4 = S1 + S2 25 = S1 + S2 + S3 36 S1 4 = S2 21 = S3 11 = k S1 = 4k; S2 = 21k; S3 = 11k; S2 S1 + S3 = 21k 4k + 11k = 7 5 Clave D 15 A C P Q O1 O2 BO r r r r r r r r p 3 2p 3 2p 3 • Siendo O1A = O2B = r = 3 µ • L AB = 3r p 3 = 3p • Long AC + Long BC = r 2p 3 + r 2p 3 = 4p Perímetro = 4p + 3p = 7p Clave A ACTIVIDADES CAP 04 R.T. DE ÁNGULOS AGUDOS A B O Q O1 P 2 2 2 2 2 2 2 p 3 3r r 2r S1 S2 S3 01 3 3 5 q 4 a ∴ tanq = 3 4 = 0,75 Clave E 02 A P a q β Ta a a B N n n C ∴ P = 3a n + a 2n 2n 2a = 3 + 1 2 = 3,5 Clave B 03 senq = 9 2b = b 7 ⇒ b = 3 7 2 Reemplazando: P = 3 7 2 2 7 = 9 14 Clave A 04 2nn q n 5 secq = n 5 n ⇒ secq = 5 Clave E 05 q 85k 84k 13k 65 A C B Perímetro: 2p = 182k .......(1) 13k = 65k ⇒ k = 5 En (1): 2p =910 Clave C 06 a 13 12 5 ⇒ 3 12 13 – 4 5 13 5 12 13 + 4 5 13 = 1 5 Clave E 07 β 2 1 3 a 2 3 7 secβ = 2 3 E = 12 3 2 2 + 9 1 3 2 3 7 3 2 – 2 1 2 ⇒ E = 4 Clave B b bH N A C B q q 7 2 08 20 3 30 3 20 40 x° y° 60120° 60° 60° 30 coty – cotx = 8 2 3 – 7 3 3 = 5 3 9 Clave C 09 B P C 4a 2a 2a 4a a 3a N A D φ a 2a 5 E = 1 4 + 4 2 2 5 + 1 5 ⇒ E = 53 3 40 Clave C 10 n an + 1 BA C En dato: a n + n + 1 n = 3 2 ⇒ a = n – 2 2 Teorema de Pitágoras: n2 + n – 2 2 2 = (n + 1)2 ⇒ n = 12 ⇒ 2 12 5 + 13 5 = 10 Clave D CUADERNO DE TRABAJO 01 • senB = b c • cotA = b a • cscB = c b A B Cb ac V = c b c – a b a + b c b = c Clave E 02 3tanA = 2cscC 3 a c = 2 b c 3a = 2b 2k 3k A B C b a c Como a2 + c2 = b2 4k2 + c2 = 9k2 c = 5k M = 5 a c + 6 b a = 5 2k 5 k + 6 3k 2k M = 2 + 9 = 11 Clave D 03 • tanq = 6 • senq = 6 7 P = ( 6)2 + 42 6 7 1 6 7 P = 12 Clave B EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 7 04 • tanq = a b • tana = b 2a b a a tana · tanq = b 2a · a b = 1 2 Clave B 05 2,4 = 24 10 = 12 5 Perímetro: 30k = 180 k = 6 5k 12k 13k 13k = 78 Clave D 06 • secA = c b • cotB = a b P = c 2 b2 – a 2 b2 + 1 = c 2 – a2 b2 + 1 P = b 2 b2 + 1 = 2 A B Cb ac Clave A 07 • senA = a c • senB = b c • tanA = a b • tanB = b a A BC b a c E = 3 a c c a – a b b a = 2 Clave D 08 Se ve: s ≅s q + q 2 = 90° q = 60° 2 2 2 a a tanq = 3 1 = 3 Clave E 09 2x + x + 2 = 8 x = 2 x + 22x 5 tanq = 5 4 Clave A 10 En dato: c b = 1 2 · b a 2ac = b2 N = c2 a2 – 2 c a + 1 2 + a b · b c · c a = c 2 – 2ac + a2 3a2 B A Cb ac Reemplazando: N = a 2 + b2 – b2 + a2 3a2 = 2a2 3a2 N = 2 3 Clave B TAREA 01 E = 2 3 2 2 – 1 2 2 = 2 2 2 2 = 1 cscq = 3 2 2 cotq = 1 2 2 3 1 2 2 q 02 tanB = b a cotB = a b cotA = b a tanA = a b A C Ba b c H = b a + a b 2 – b a – a b 2 = 2 + 2 = 4 03 Se cumple: • tanq + cotq = a b + b a • (a + b)2 – (a – b)2 = a2 + b2 4ab = a2 + b2 4 = a 2 + b2 ab = a b + b a E = a b + b a = = 4 04 • m2 + n2 = (2 mn)2 m2 + n2 = 4mn m n + n m = 4 • tana + 1 tana = 4 tan2a – 4tana + 1 = 0 tan2a – 4tana + 4 = 3 (tana – 2)2 = 3 REFORZANDO 01 Clave C 02 M = a 2 b2 + c 2 b2 + b 2 c2 – a 2 c2 M = a 2 + c2 b2 + b 2 – a2 c2 M = b 2 b2 + c 2 c2 = 2 C B Ac a b Clave B 03 R = 30° cotR = 3 K = 32 + 2 = 5 Clave B 04 Clave A W = 17 3 34 2 – 1 W = 7 2 = 3,5 3 5 34 q K = a c + c a a b ⋅ c b K = a2 + c2 ac · ac b2 K = b2 ac ⋅ ac b2 = 1 A B Ca c b 05 Perímetro: 910 Clave C 06 Si CD = AB (a + 2)2 + b2 = (b + 2)2 + a2 a = b q = β cosq = cosβ senβ = senq M = 1 Clave A 07 A B Ca c b • b2 = 5 2 ac a2 + c2 = 5 2 ac 2a2 – 5ac + 2c2 = 0 2a – c ⇒ c = 2a a – 2c • Ĉ > Â c > a cotC = a c = 1 2 Clave B 08 A N q q r r 2r 2rO tanq = 2r r tanq = 2 Clave E 09 cotq = 3r – r r 3 r – r r q cotq = 3 – 1 Clave D 10 tana = 3 1 tana = 1 A B 45° D CML 3 3 2 1 2L L a q Clave E 11 ACE a = 53° 2 + 53° 2 a = 53° A B C DO E r r rr 53°/2 a 53° 2 Clave E 13K = 65 K = 5 AB = 420 AC = 425 BC = 65 A B C65 = 13K 85K84K q β A D E C B 2 2 b a EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 8 12 Clave D 13 • 78k + 77 = 89k k = 7 • Área = 78k ⋅ 80k 2 B C A H 39k 80 k 89k 39k 78k + 77 Área = 152 880 cm2 Clave A 14 •12k = 48 k = 4 • Perímetro: 18k + 72 = 144 cm 48 12k 5k 13k 12 cm 12 cm q Clave B 15 ABC: (2b)2 + (2c)2 = (2a)2 b2 + c2 = a2 CBM: b2 + (2c)2 = CM2 ABN: (2b)2 + c2 = AN2 5(b2 + c2) = CM2 + AN2 CM2 + AN2 = 5a2 Clave B ACTIVIDADES CAP 05 R.T. DE ÁNGULOS NOTABLES 01 I – V; II – F; III – F; IV – V Clave A 02 E = 32 (2)(1) 2 1 3 2 + ( 2)2 ⇒ E = 9 4 = 2,25 Clave B 03 x 1 2 – 2 = x 3 ∴ x = –4(1 + 2 3) 11 Clave A 04 8 3 4 – x(1) = 3csc32°sen32° ∴ x = 3 Clave E F 4 4K 11K 11K 4k 7k 7 A D CB E q q tanq = 7k 11k tanq = 7 11 A B C NM b c cb 2a 05 30°A B H C 45° n n b 2n = 3 n 2 n 3 2n = 3 ⇒ n = 3 2 ⇒ b = 3 2 3 + 3 2 ⇒ b = 3 + 3 2 Clave B 06 x – 30° = 70° – x 2x = 100° ∴ x = 50° Clave C 07 3x + 30° + 5x – 4° = 90° 8x = 64° ∴ x = 8° Clave D 08 sec(3x + 43°) = csc(8x – 30°) ⇒ 3x + 43° + 8x – 30° = 90° 11x = 77° ∴ x = 7° Clave B 09 53° 3 H 2 45 O B E A q 37° cotq = 4 2 ∴ cotq = 2 Clave B 10 2 1 H 1 O C B D E A 1 1 1 1 q q 3 – 1 OED: ED = 3 CHD: cotq = 3 – 1 1 Clave E CUADERNO DE TRABAJO 01 8 3 4 – x(1) 1 2 = 3 2 1 6 – x = 3 x = 3 Clave C 02 tanq = 9 31 B 15 31 12 9 A C 37° H Clave B 03 cota = 5 4 E = 41 · 4 41 + 8 5 4 = 14 4 5 41 Clave D 04 60° – x + 70° – 3x = 90° x = 10° Clave D 05 90° – 2x = 3x x = 18° csc30° · tan60° = 2 · 3 1 = 2 3 Clave B 06 (a + b + c) + (a – b + c) = 90° a + c = 45° M = tan60° · sen45° M = 3 1 × 2 2 = 6 2 Clave E 07 sen3x · sec6x = 1 sen3x = cos6x 3x + 6x = 90° x = 10° x = p 18 Clave C 08 E = 1 32 + 1 32 + 2 32 E = 6 319 4 1 1 A C B 2 3 60° Clave A 09 tan(30° – q) = cot(30° + 3q) 30° – q + 30° + 3q = 90° q = 15° 30° 15° 15° 20 20x x = 10 Clave B 10 csc(90° – a) = 5 4 sen(90° – a) = 4 5 90° – a = 53° a = 37° k = sen37° · tan53° + cos37° = 3 5 · 4 3 + 4 5 = 8 5 Clave D TAREA 01 E: 1 2 ⋅1 ⋅ 4 5 = 4 10 = 2 5 02 • sen(2x – 10°) = cos(4x + 20°) (2x – 10°) + (4x + 20°) = 90° 3x = 40° • sen(3x + 5°) = sen45° = 2 2 EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 9 03 6 2 12 = a 6 36 45° 30° 6 b B A H C a + b = 18 + 6 3 04 • sec(2x + 15°) = csc(3x + 20°) 2x + 15° + 3x + 20° = 90° x = 11° • tan(4x + 1°) = tan45° = 1 REFORZANDO 01 Clave B 02 2x + 3x = 90° x = 18° sen(36° – 6°) + 2ctg(54° – 9°) – cos (72° – 12°) sen30°+ 2ctg45° – cos60° = 2 Clave B 03 secx = cscy x + y = 90° 2° + 2β + 4a – 2° = 90° 2β + 4a = 90° β + 2a = 45° R = sec2β – tg45° csc4a – ctg45° = csc4a – 1 csc4a – 1 = 1 Clave A 04 sena = cosβ 2x2 + 5x – 1 = 2 – 3x – x2 3x2 + 8x – 3 = 0 x = 1 3 sena = 2x2 + 5x – 1 sena = cosβ = 8 9 tana = 8 17 , senβ = 17 9 M = 2 17 8 17 + 17 9 + 2 9 M = 20 Clave A 05 • cosx = 2 3 tanx = 5 2 cscx = 3 5 • M = 5 2 ⋅ 3 5 + 2 ⋅ 1 2 2 = 2 Clave D ctga + 2tgβ = 6 ctga + 2ctga = 6 ctga = 2 5 5 + 2 5 = 7 1 2 5 a β 17 8 9 a β 5 2 3 x a 06 β a 1 2 5 tgβ = 2ctgβ ⋅ ctgβ 3ctg2β + ctg2β tgβ = 1 2 Luego: 5 (secβ – sena) = 5 5 2 – 2 5 = 5 2 – 2 = 1 2 Clave D 07 cos6x = sen(8y + 10°) 6x + 8y = 80° sen(40° – x – y) csc(40° – x – y) + 2tg(30° + x+ 3y)ctg(30° + x + 3y) + 3sen46°sec(80° – 36°) ⇒ 1 + 2(1) + 3sen46°csc46° = 6 Clave E 08 sec33°tga – sec33° = 2sec33°sen(β – 8°) csc(β – 8°) – sec33°tga tga – 1 = 2 – tga 2tga = 3 tga = 3 2 ( 13 – 2) 13 + 2 3 + 13 2 2 3 + 13 4 = 25 4 Clave D 09 4x – 30° = 40° – 3x x = 10° sen20° – cos70° cos70° – cos70° = 0 Clave E 10 1 2 ( 17a)(5a)sena = 1 2 ⋅ 4a ⋅ 4a sena = 16 5 17 , csca = 5 17 16 256 5 25(17) 256 – 4 = 81 Clave B aa/2 3 2 13 13 3tg(4x – 30°)sen32° sen32° ⋅ sen60° ⋅ tg(40° – 3x) = 2 3tg(4x – 30°) = 2 3 2 tg(40° – 3x) a A D CB 4a 5a 4a 3aa 17 a E 11 tanx + 2tanx ⋅ cotx – 6 ⋅ 1 2 ⋅ cotx = 0 1 cotx = 1 ⇒ x = 45° Piden: 2 2 (cos45° + sec45°) 2 2 1 2 + 2 = 6 Clave C 12 sec(a + 2b)cos(25° – c) = csc(b – 2a)cos(25° – c) sec(a + 2b) = csc(b – 2a) a + 2b + b – 2a = 90° 3b – a = 90° M = sec(90°–30°) + tan 90°+60° 2 90° 3 – 15° M = sec60° + tan75° ⋅ tan15° M = 2 + (2 + 3 )(2 – 3 ) = 3 Clave D 13 cot C 2 = a + b c = a c + cscC cot C 2 – cscC = a c cot C 2 = cot (2C – 10°) C 2 = 2C – 10° C = 20° 3 sen9C + cos(3C + 10°) sen60° + cos30° = 3 Clave C 14 sena ⋅ x2 + 2x ⋅ sena + cosβ = 0 sena ⋅ x2 + 2sena ⋅ x + cosβ = 0 x = –2sena ± 4sen2a – 4senacosβ 2sena 4sen2a = 4senacosβ sena = cosβ a + β = 90° Clave A 15 (sec2A)° – (csc2B)g ⋅ 9° 10g = p 18 rad ⋅ 180° prad sec2A – 9 10 csc2B = 10 10sec2A – 9csc2B = 100 10csc2B – 9csc2B = 100 csc2B = 100 cscB = 10 tanA = 3 11 Clave C A B EC c b a b C 2 C 2 A BC 1 10 3 11 EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 10 ACTIVIDADES CAP 06 RESOLUCIÓN DE TRIÁNGULOS RECTÁNGULOS 01 B H 20 A hcotq h htanq q q C htanq + hcotq = 20 h 25 12 = 20 ⇒ h = 9,6 Clave E 02 ABC: EC = m 2 secq ECD: DC = m 2 secqcota Clave C 03 n b n B q q A N C tanq = b n = n n + b b2 + bn = n2 ⇒ b2 – n2 = –bn P = b n – n b = b 2 – n2 bn = –bn bn ⇒ P = –1 Clave E 04 CA B MS q a S n a b S = an 2 senq = nb 2 sena ⇒ senq sena = b a Clave B 05 A C H B L 2 secq L 2 secq L/2 L/2 q q Perímetro de ABC: 2p = L + Lsecq 2p = L(1 + secq) Clave B 06 Sea: x la longitud del lado del cuadrado PQRS APQ: AP = xcotq RSC: SC = xcotq ⇒ 2xcotq + x = L ⇒ x = L 2cotq + 1 Clave C 07 CB = 2cotq = 7tana ⇒ 2 7 1 tana = 1 cotq ⇒ tanq = 2 7 cota Clave B 08 B q A m mtanqmsecq C Perímetro: 2p = m + mtanq + msecq ∴ 2p = m(1 + tanq + secq) Clave B 09 B E DA acota acota a x a β C ABC: x = 2acotasenβ Clave B 10 k x xcos6q xc os q xc os 3 q xc os 2 q xc os 4 q xc os 5 q q q q qq q q xcos6q = ktanq ∴ x = ksec6qtanq Clave C CUADERNO DE TRABAJO 01 ED = m(cosq – senq) A E B C D m Clave C 02 • BC = mtanq • CD = mtanq · cosa Clave D 03 tana = 5 5 2 = 1 2 tanβ = 0,5 1 = 1 2 tana + tanb = 1 2 1 1 0,51,5 5 2 5 β β Clave D 04 Rcosq + x = R x = R(1 – cosq) R xO E A B Clave A 05 AB = ncota Área = AB · BC 2 A B Cn Área = n 2cota 2 Clave C 06 CD = L tan a 2 Área = L2 tan a 2 A M B C D L L 2 Clave B 07 2hcotq + hcota = d h = d 2cotq + cota M h h Clave A 08 2 3 13 x 3 x 3 = 13 3 x = 13 9 3 3 3 1 11 2 x x–1 = 13 9 Clave B 09 Área ABC = (6)(8)senq 2 = 24senq Área BDE = (2)(7)senq 2 = 7senq Asombreada = 24senq – 7senq = 17senq Clave A 10 Área = px 2 = pqcosa 2 + xqsena 2 px = pqcosa + xqsena x(p – qsena) = pqcosa x = pqcosa p – qsena D AC B xp q Clave C TAREA 01 BC: mtana CD: mtana ⋅ cosβ 02 x = mtana ⋅ secβ mtana m x a β 03 B A 4 C 2 3 8 3 60° 30 ° • Área: (8 3)(2 3) 2 = 24 EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 11 04 Perímetro = n(1 + cscq + cotq) REFORZANDO 01 y = 4secq x = ytanq x = 4secq senq cosq x = 4sec2q ⋅ senq Clave D 02 • ED = 6sena • AD = 3csca AE = AD – ED = 3(csca – 2sena) Clave B 03 BD = n⋅tan53° = 4n 3 CD BD = 3 2 CD = 4n 3 3⋅2 CD = 2n 3 3 Clave C 04 x = 16cot37° x = 16 ⋅ 4 3 x = 64 3 Clave C 05 • BC = 4tana • CD BC = cotq CD = 4tana ⋅ cotq Clave B 06 A DQ O 3 3 aa a B CN T M P 6 NT = TP = 3sena ND = 6csca PD = 6csca – 6sena ncotq ncscqA C B n q A B y x E C q q 4 B C 3 3 EA D a a CB A D 12 20 16 53° 37 ° 37° x = 6 1 sena – sena = 6(1 – sen2a)csca Clave B 07 • Tenemos DC = 2 ⋅ AC Si AC = x DC = 2x • T.P. (2x + 10)2 + x2 = 625 4x2 + 40x + 100 + x2 – 625 = 0 x = 7 ctga + 5 csca + ctgβ + 4 7 = 2 + 5 ( 5) + 24 7 + 4 7 = 7 + 4 = 11 Clave D 08 Área = 1 ⋅ k 2 = 1 k = 2 tga = 1 2 = BC AC = 4(2) AC AC = 16 EC = 14 ED = 2 FD = 5 Además FB = 7 5 tgq = 7 Clave A 09 tga = 4 3 = 4t 3t ; 3k = 5t k = 5t 3 3ctgβ = 3 8t 3 t = 8 Clave C 10 7 5 A B CD 25 10 2x = 14 x = 7 β a B A CDEk 1 F 6p 7p 4k qa 8 5 C A D a a β E B t 4t 3t 2k 5t k 4t 3 8t 3 4sena 2sena 3cosa B 3 1 2 M P Q H N A C D a a a En ADN: 4sena = CD = PQ 4sena = 2sena + 3cosa 2sena = 3cosa tga = 3 2 tga + ctga = 3 2 + 2 3 = 13 6 Clave A 11 seca = 5 3 ; t = 3k 5 cotq = 5k + 12 5 k 9 5 k = 37 9 9ctgq – 5 = 37 – 5 = 32 Clave A 12 secq + tgq = 5 3 + 4 3 = 3 17k A 4k 4k 5k3k k D T B Ca q a Clave C 13 T.P.: DE = 2 2; AD = 2 6 M = 3 + 2 4 2 2 2 2 6 + 4 2 2 = 5 6 + 2 M = 5 2 6 – 1 Clave A 14 25k25 k 25k 7k 7k k q18k 24k 16° B C A D ⇒ q 18k k 2cot2q = ? Entonces: tanq = k 18k tanq = 1 18 Por identidad del ángulo doble tan2q = 2tanq 1 – tan2q Reemplazando: 2cot2q = 323 18 Clave C 3k 5t 4k 3k a a q 5k A B C E D 9 5 k = 3t 4t = 12 5 C AM D 3 q q aa/2 a 3 21O BE 2 2 6 2 2 EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 12 15 3 3 53° a a a q q A B T C PE8k 3k 8 3k 6–8k D • 9ABC (notable 37 y 53) Sea AB = 8 BC = 6 • 9ABD ∼ 9TBE: BT = 3k ∧ TE = 8k • tana = 3 8 = 8k 8 + 3k k = 24 55 • ECP: tanq = 3k 6 – 8k Reemplazando el valor de k: tanq = 3 ⋅ 24 25 6 – 8 ⋅ 24 55 tanq = 12 23 Clave A ACTIVIDADES CAP 07 ÁNGULOS VERTICALES Y HORIZONTALES 01 37° 45° x 9/4 3 3 3 4 4 3 4 x + 9 4 = 12 4 ⇒ x = 3 4 = 0,75 m Clave B 02 3 3 60° 1,73 3,46 a 2 3 3 3 33 ⇒ cota = 2 3 + 3 3 3 ∴ cota = 2 + 3 3 Clave D 03 2n 10 km2n – d (2n – d) 3 d30° 30° a a 2d n 3 d 3A B De la figura: (2n – d) 3 = n 3 + d 3 2n – d = n + d ⇒ n = 2d = 5 km Se pide: AB = 2d = n = 5 km Clave A 04 6 3 T H B A 4n 3n 30° 53° ⇒ 6 3 + 3n = 4n 3 n = 6(4 + 3) 13 ∴ TH = 24(4 + 3) 13 Clave B 05 x 3 9 3 33 x/ 3 x x 30° 30° 60° x 3 + 3 + x 3 = 9 3 ⇒ 4 3x = 24 3 ∴ x = 6 m Clave D 06 h hcotφ H A C B hcota d φ a Dato: cotφ + cota = 1 2 hcotφ + hcota = d ⇒ h 1 2 = d ∴ h = 2d Clave A 07 H A B P M d a β h 2 cota h 2 cotβ h 2 h 2 ⇒ h 2 cota + h 2 cotβ = d ∴ h = 2d cota + cotβ Clave D 08 S2 S1 h β β hcota hcotβ a a S1 + S2 = 4(cota + cotβ) ⇒ hcota + hcotβ = 4(cota + cotβ) ∴ h = 4 Clave B 09 12 16 37° 37° 45° 45° P H A B d 12 ⇒ d = 12 + 16 ∴ h = 28 m Clave C 10 d1 d2 a a β β γ γ h a a 2a P H A B C ⇒ d1 d2 = a 2a ∴ d1 d2 = 1 2 Clave ACUADERNO DE TRABAJO 01 Del gráfico se observa: hcota – hcotb = 20 h(cota – cotb) = 20 h(0,25) = 20 h = 80 h 20 Clave B 02 Del gráfico: x + 36 = 48 x = 12 53°45° x 3(12) = 36 48 Clave C 03 D = h(cota – cotb) h a b hcotbD hcota Clave D 04 tanb – tana = 3 10 h 20 – h 50 = 9 10 h = 30 h 30 20AB Clave B 05 30° 2040 H = 60 Clave E 06 24a = 300 + 14a a = 30 h = 7a = 7(30) 7a 10a 300 100 14a h 53°/216° h = 210 Clave C EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 13 07 cot15° = 3d 1,5 30° 60° 15° 2d d 2d 1,5 2d = 2 + 3 Clave B 08 Htan2q = H – h (H – h) H h 90°– q h H = 1 – tan2q Clave C 09 3h = 3(6) = 24 h = 6 3h 3h 45° 53° Clave C 10 mBAOB = 90° – (22°30' + 11°15') mBAOB = 56°15' a = 180° – mBAOB 2 a = 61°52'30'' q = a – 11°15' q = 50°37'30'' A B O N N 11 °15 ' 11 °15 ' 56°15' 22°30' E E d d B se encuentra en dirección S50°37'30''E respecto de A. Clave C TAREA 01 D = h(cota – cotb) a D b h 02 • 3 4 = 24 – h 24 h = 6 53° (24 – h) (24 – h) h 24 (24 – h) 45 ° 45° 53° 03 4k = 16 k = 4 x = 4 45° 4k x k 3k 16 37° 37°45° 04 x = h(cotb – cota) a h b x hcota hcotb REFORZANDO 01 x = 225 3 Clave D 02 x = 80 Clave A 03 H = 18 Clave A 04 H = 25k H = 25 3,6 9 H = 10 Clave A 05 x = 8 Clave D 06 Clave B 07 • cot2q = x 25 x 25 = 12 5 13 B 12 12 A C x 5 2q q q x = 60 Clave E 08 cotq = 4 5 3 37° 8d 4d 5d 3d S E E q 4 5d N Clave B x 225 30° 30° x 60 37° 37° 15° 15° 30° 36 H 36 53° 12k 37° 3,6 9k 16k H x 24 24 32 37° 45° 150 m 200 m 53° 53° 09 H = 6(1,7) + 1,5 H = 11,9 Clave C 10 3h = 3(6) = 18 Clave A 11 a a90 – a 1 m 1 m1 mx x 2 m 5 m tana = x 5 = 2 x x = 10 cota = 10 2 Clave E 12 x = dtanq d d x q q q Clave A 13 cota – tana = 2 tana + cota = 2 2 Clave B 14 cotβ = 4cota + 3tana 1 cotβ = 4 3 Clave D 15 17 6cota 7tanaa a q q 6 7 7tana + 6 tana = 17 7tan2a – 17tana + 6 = 0 30° 60° 12 12 1,5 1,5 H 6 6 3 3h 45° 53° 6 = h 3h 37 ° a a h 2(H–h) (H–h)tana (H–h)cota h H (H – h) β a a 4cota 3tana 1 11 EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 14 tana = 3 7 ∨ tana = 2 tanq = 7 3 ∨ tanq = 1 2 Clave A ACTIVIDADES CAP 08 PLANO CARTESIANO 01 PQ = [a – 2 – (a + 3)]2 + [b + 1 – (b – 1)]2 PQ = (–5)2 + 22 ⇒ PQ = 29 Clave D 02 G –4 + 2 + 8 3 ; 1 + 5 + 3 3 ⇒ G(2;3) Clave A 03 S = 1 2 1 1 –3 5 5 0 1 1 = 1 2 |10 + 22| ⇒ S = 16 Clave B 04 h S H A(–1; 1) C(5; –3)B(3; 7) BC = (3 – 5)2 + (7 – (–3)2 ⇒ BC = 2 26 S = 1 2 –1 1 5 –3 3 7 –1 1 ⇒ S = 26 (2 26)h 2 = 26 ⇒ h = 26 Clave B 05 L1: y + 2 = 4 – (–2) 7 – (–1) (x + 1) ⇒ y = 3 4 x – 5 4 L2: y – 3 = –1 – 3 8 – (–2) (x + 2) ⇒ y = – 2x 5 + 11 5 Igualando: 3 4 x – 5 4 = – 2x 5 + 11 5 ⇒ x = 3 y = 1 ∴ P = (3; 1) Clave C 06 Q(4; –2) P(–2; 10) 2n n A(x; y) x = –2(2) + (4)1 2 + 1 = 0 y = 10(2) + (–2)1 2 + 1 = 6 ∴ A(0; 6) Clave D 07 x + (–2) = 1 + 0 ⇒ x = 3 y + 6 = 4 + 8 ⇒ y = 6 ∴ x + y = 9 Clave B 7tana – 3 tana – 2 08 C(x; 8) M(a; b) B(–1; 5) A(1; –7) n n Pendiente: ⇒ 5 – (–7) –1 – 1 = 8 – 5 x – (–1) ⇒ x = – 3 2 M: punto medio de BC 2a = –1 – 3 2 ⇒ a = – 5 4 2b = 5 + 8 ⇒ b = 13 2 ∴ M – 5 4 ; 13 2 Clave C 09 P(1; 0); Q = 5 2 ; 0 ⇒ PQ = 3 2 Área: SPAQ = 1 2 3 2 (1) ⇒ SPAQ = 3 4 Clave A 10 Menor distancia: ⇒ 1 + d = 32 + 42 1 d 1 0 Y X P(3; 4) ∴ d = 4 Clave B CUADERNO DE TRABAJO 01 x = –8 + 2 2 = –6 2 = –3 ; y = 6 – 4 2 = 2 2 = 1 M(–3; 1) Clave E 02 Graficando: 2 3 A(2; –3) B(–4; 1) P(x0; y0) x0 = 2(–4) + 3(2) 3 = –8 + 6 5 = –2 5 y0 = 2(1) + 3(–3) 2 + 3 = 2 – 9 5 = –7 5 P(x0; y0) = P 2 5 7 5 – ; – Clave B 03 x0 = 2(6) + 5(2) 2 + 5 = 12 + 10 7 = 22 7 y0 = 2(–2) + 5(7) 2 + 5 = –4 + 35 7 = 31 7 P(x0; y0) = P 22 7 31 7 ; Clave D 04 G es baricentro. A(2; 5) C(8; 3) B(–4; 1) M N G(x0; y0) x0 = –3 + 6 + 9 3 = 12 3 = 4 y0 = 4 – 5 – 11 3 = – 12 3 = –4 G(x0; y0) = G(4; –4) Clave B 05 + = +–8 4 –15 –19 3 20 8 31 3 –4 4 3 2 1 –5 2 A B C A Finalmente: S = 31 – (–19) 3 S = 31 + 19 2 = 50 2 Y X C(4; –5) A(3; 2) B(–4; 1) S S = 25 Clave C 06 l = (–1 – 0)2 + (2 – 3)2 l = 1 + 1 l = 2 Hallando el perímetro: 2p = 4l 2p = 4 2 B(0; 3)A(–1; 2) Clave C 07 P(–12 + 5; –1 + 2) = P(–7; 1) Q(–7 + 5; 1 + 2) = Q(–2; 3) B(–12; –1) A(3; 5) 5 P Q 5 5 2 2 2 15 Clave D 08 • c – b 2 = b 3 = c 5 b = 3 5 c • b + c = 32 3 3 5 c + c = 32 3 Y X (–3; 0) 2 3 (2; c) (0; b) c – b b c = 20 3 b = 4 Clave D 09 • AD = DB (a + 8)2 + (0 – 0)2 = (a – 10)2 + 122 (a + 8)2 = (a – 10)2 + 122 (a + 8)2 – (a – 10)2 = 144 18(2a – 2) = 144 a = 5 Clave B 10 S/4 S/4 S/4 S/4 C(4; –6) B(6; 8) B C A Triángulo mediano A(–2; 4) EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 15 S = 1 2 A C B A = 1 2 + +16 –36 –16 –36 12 32 24 68 –2 4 6 –2 4 –6 8 4 S = 52 S 4 = 52 4 = 13 Clave C TAREA 01 El punto medio es: M = 7 + 5 2 ; 3 + 1(–1) 2 M = (6; 1) 02 Si el baricentro es (x; y) x = –2 + 1 + 4 3 = 1 y = 3 – 3 + 2 3 = 2 3 Las coordenadas 1; 2 3 03 AB = (2 + 4)2 + (5 + 1)2 = 6 2 BC = (2 – 5)2 + (5 + 1)2 = 3 5 AC = (5 + 4)2 + (–1 + 1)2 = 9 Perímetro = 6 2 + 3 5 + 9 04 1 3 5 0 7 1 1 3 A B C A S = 1 2 = 1 2 ⇒ S = 1 2 |26 – 16| S = 5 REFORZANDO 01 I. (V) II. (F) III. (V) IV. (V) VFVV Clave B 02 OA = (–5)2 + (3)2 = 34 OB = 32 + 42 = 25 OC = (–3)2 + (–2)2 = 13 OD = (–4)2 + 12 = 17 OE = 52 + 22 = 29 El punto C esta mas cerca. Clave C 03 • a + 3 2 = 8 a = 13 • b + 5 2 = 9 b = 13 M = a – b = 0 Clave A A(1; 3) C(7; 1) B(5; 0) 04 Clave E 05 d(AB) = (7 – 1)2 + (5 – 2)2 d(AB) = 362 + 9 = 3 5 Área = (3 5)2 = 45 Clave B 06 • S1 = 3 ⋅ 6 2 = 9 • S2 = 4 ⋅ 2 2 = 4 • S3 = 4 ⋅ 2 2 = 4 B D A 6 6 S S2 S3 S4 S1 EO Y X • S4 = 2 ⋅ 3 2 = 3 S + S1 + S2 + S3 + S4 = 6 ⋅ 6 S + 9 + 4 + 4 + 3 = 36 S = 16 Clave A 07 B(3; 7) C(5; 5) A(1; 2) D(x; y) Y X 1 + 5 = 3 + x x = 3 7 + y = 2 + 5 y = 0 xy = 3 · 0 = 0 Clave E 08 1 + (–1) + x 3 = 0 x = 0 1 + 3 + y 3 = 0 y = –4 C(0; –4) Clave E 09 M – 1 + 1 2 ; 5 + 1 2 = M(0; 3) MC = (4 – 0)2 + (5 – 3)2 = 2 5 Clave E (7; 7) 6 2 22 222 2 2 2 2 2 2 6 (5; 5) (3; 3) (1; 1) C(4; 5) M A(–1; 5) B(1; 1) 10 AB = 92 + 122 = 15 AC = 252 + 02 = 25 BC = 162 + 122 = 20 El 9 es rectángulo Clave D 11 C(7; 9) P(x; y) 3k 4k A(0; 0) • x = 0(3) + 7(4) 4 + 3 = 4 • y = 0(3) + 9(4) 4 + 3 = 36 7 x + y = 36 7 + 4 = 64 7 Clave C 12 El baricentro del 9ABC es el mismo que el baricentro del 9MNP x = 1 + 2 + (–6) 3 = –1 y = 3 + (–1) + (–5) 3 = –1 El baricentro es: (–1; –1) (–1) + (–1) = –2 Clave E 13 Siendo: G –5 + 3 – 1 3 ; 3 + 2 – 5 3 = G –1; 1 3 2 13C(–1; –4) B(3; 2) h q G –1; 1 3 –1 1 3 –1 –4 3 2 –1 1 3 S = 1 2 = 1 2 |3 + 43 3 |= 52 6 = 26 3 2 13 ⋅ h 2 = 26 3 h = 2 13 3 Clave B 14 • –a –b +r = x r x = ar r – b • S = 1 2 (xr) S = ar2 2(r – b) Clave B 20 15 25 (–b; –a) (a; b) r x–a –b r r EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 16 15 Siendo C(x; y) • –5 + x = –3 + 2 x = 4 • –1 + 2 = –5 + y y = 6 S = 1 2 |–42 – 40|= 41 S1 + S2 = 41 2 Clave B ACTIVIDADES CAP 09 R.T. DE ÁNGULOS DE CUALQUIER MEDIDA 01 I. (+) (–)(–) = (+) II. (–)(–) (–) = (–) III. (+)(+) – (–) = (+) Clave A 02 270° < a < 360° ⇒ 135° < a 2 < 180° 90° < a 3 < 120° I. T = (+)(–) = (–) II. M = [–(–)][–(+)] = (–) III. M + T = (–) + (–) = (–) Clave E 03 x = –3; y = –6; r = 3 5 G = 5 –6 3 5 – –3 3 5 = –1 Clave B 04 x = –3; y = 4 r = 5 seca + tana = 5 –3 + 4 –3 = –3 Clave B 05 β φ r r 0 Y X (–b; –a) (a; b) ⇒ tanφtanβ = –a –b b a ∴ tanφtanβ = 1 Clave E 06 a = 5k; β = 2k 5k – 2k = 360°n k = 120°n a = 600°n; β = 240°n 1441 < 600n – 240n < 2159 4,01 ... < n < 5,99 ... ⇒ n = 5 ∴ a = 600°(5) = 3000° Clave C A D C B A S = 1 2 = 1 2 –5 –5 –3 2 4 6 2 –1 –5 –5 07 r r 0 q Y P(–3; 5) (0; 0) H(3; –5) X x = 3; y = –5 r2 = 32 + (–5)2 ⇒ r = 34 ⇒ F = 3 34 3 2 – –5 3 ∴ F = 13 Clave A 08 0 a –β Y (–2; 4) X 2 5 a – β = 270° –β = 270° – a sec(–β) = sec(270° – a) secβ = – csca tanβ = cota ∴ sec2β – tanβ = – 2 5 4 2 – –2 4 = 7 4 Clave C 09 Y (–4; –3) (–3; –4) X –β ω –q a a – β = 270° –β = 270° – a cot(–β) = cot(270° – a) cotβ = –tana ω – q = –270° q = 270° + ω tanq = –cotω ∴ tanq·cotβ = – 4 3 – 4 3 = 16 9 Clave C 10 ω –a –β φ Y (–1; 2) X (–1; – 3) tanβ = –cotφ secβ = cscφ sena = cosω ⇒ 5 –1 5 – 3 2 – 3 + 3 –1 3 ∴ 1+ 2 – 1 = 2 Clave C CUADERNO DE TRABAJO 01 • csca < 0 a IIC o IIIC • tana > 0 a IC o IIIC a IIIC Clave C 02 • csca = r y csca = 5 –4 ; r2 = 32 + 42 • cota = x y cota = –3 –4 = 3 4 E = –5 4 + 3 4 = –2 4 = –1 2 Clave E 03 El ángulo coterminal es: 360°k + 20° 750° < 360°k + 20° < 8000° 37,5° < 18°k + 1 < 400° 21; 22 • 360°(21) + 20 = 7580° • 360°(22) + 20 = 7940° 15520° Clave E 04 a IIIQ b IVQ P a 2 a 2 – –3; Q(a 3; –a) tana = 3 1 tanb = 3 –1 E = tana + tanb = 0 = 0 Clave A 05 Como a y b son coterminales se cumple a – b = 360°k E = tan(3(a – b) + 45°) + csca · sena sen(2(a – b) + 30°) E = tan45° + 1 sen30° = 2 1 2 = 4 Clave C 06 I(F) II(V) III(F) IV(F) Solo II. Clave C 07 tanq = y x = 4 –7 tanq = –4 7 Y X (–7; 4) 4 7 –7 (4; 7) Clave B 08 • tana = –1 3 a IIC K = 3 10 –3 + 5 10 1 2(–3) Y X–3 1 10 K = 1 –2 10 2 = – 10 10 Clave B 09 tanq = –4 3 ; (q IVQ) r = 5 • cscq = –5 4 • secq = 3 5 Y X (3; –4) 3 5 –4 E = 12 5 3 +–5 4 = 5 Clave A EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 17 10 (4k + 1) p 2 ; (4k – 1) p 2 ; (2k – 1) p 2 son ángulos cuadrantales y lo reemplazamos por sus coterminales: E = a 3cot90° + sen270° atan180° + cos180° = a 3(0) + (–1) a(0) + (–1) = 1 Clave C TAREA 01 x = – 12 y = 5 r = 13 E = 13 –12 + 5 –12 = –18 12 = – 3 2 02 senq = –1 3 = y r y = – 1; r = 3: x = –2 2 secq = 3 –2 2 tanq = –1 –2 2 E = 2 –3 2 2 – 1 2 2 = 2 –4 2 2 = –2 03 Q = (+) ⋅ (+) (–) ⋅ (+) = (–) 04 • a = 5k ∧ q = 3k 5k – 3k = 360n k = 180n ∧ a = 900n; q = 540n • 4032 < 5k + 3k < 4608 4032 < 1440n < 4608 n = 3 a = 2700°; q = 1620° REFORZANDO 01 E = –sen270° + cos90° –csc90° – tanp E = –(–1) + 0 –1 – 0 = 1 –1 = –1 Clave A 02 sen 3p 2 = –1; cos2p = 1 sen p 2 = 1; csc p 2 = 1 sec p = –1 E = –(x – y)2 – 4xy(1) y2(1) + x2(1) – 2xy(–1) = –(x + y)2 (x + y)2 = –1 Clave A 03 • a2 + b2 = c2 • a b c + b a c = c 2ab = c2 2ab = a2 + b2 (a – b)2 = 0 a = b M = b a + a b = 1 + 1 = 2 Clave C 04 • T = (+) + (+) = (+) • R = (–) + (–) = (–) • C = [(+) + (+)][(–) + (–)] = (–) (+)(–)(–) Clave C 05 tanβ = –2 –3 = 2 3 Clave B 06 r = (–3)2 + 42 = 5 E = senq · cosq E = 4 5 –3 5 = – 12 25 Clave A 07 E = sen(–a) · cos(–a) E = –sena ⋅ cosa X Y (–1; –2) a E = – –2 5 –1 5 = – 2 5 Clave B 08 5(1 – 2sen2x) + 3senx = 4 10sen2x – 3senx – 1= 0 senx = 1 2 ∨ senx = – 1 5 Como x ∈ III C senx = – 1 5 y = – 1; r = 5 cosx = – 2 6 5 Clave D 09 senφ = – 3 5 y = –3; r = 5 ∧ x = 4 k = r x + y x k = 5 4 – 3 4 = 2 4 = 1 2 Clave C 10 E = sen90° + cos180° sen270° E = 1 – 1 –1 = 0 Clave C 11 a < β y cosa = cscβ X Y (–3; –2) (2; –3) β X Y(–3; 4) r = 5 q 2senx – 1 5senx 1 Piden: E = 2seca senβ = 2 cosa 1 cscβ = 2 Clave B 12 Siendo a el menor: 304° < a < 430° El mayor ángulo es: 360°k + a La suma es: 360°k + 2a = 2480° ......(3) a = 1240° – 180°k Reemplazo: 304° < 1240° – 180°k < 430° (2) (1) De (1) y (2): k = 5 De(3): a = 340° El mayor ángulo es: 2140° Clave D 13 E = cotβ – cscβ E = x y – r y E = 15 –20 – 25 –20 = –10 –20 = 1 2 Clave A 14 361° ∈ IC sen361° = (+) 455° ∈ IIC cos455° = (–) I. (+) ⋅ (–) = (–) II. (–) – (–) = (–) III. (+) ⋅ (+) = (+) (–) (–)(+) Clave C 15 (3sena – 4)(5sena + 2) = 0 sena = –2 5 Como a ∈ IIIC y = –2; r = 5; x = – 21 cota ⋅ cosa = – 21 –2 – 21 5 = –2,1 Clave D ACTIVIDADES CAP 10 CIRCUNFERENCIA TRIGONOMÉTRICA 01 Y C(senq;cosq) B(5;0)A(–4;0) q X senq AB = 5 – (–4) = 9 ; senq = cosq ⇒ q = p 4 Área: 1 2 (9)senq = 9 2 cosq Pero: 9 2 cosq > 9 4 ⇒ q ∈ 0 ; p 4 Clave B EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 18 02 Área: 1 2 (2)senq = 2 3 ⇒ senq = 2 3 Pitágoras: 2 3 2 + cos2q = 12 Y X B A C CT 1 11 senq q cosq = 5 2 Clave D 03 Área S = (2cos)(1 – senq) S = cos(1 – senq) Y X S CT 1 senqse nq cosqcosq q Clave B 04 Área: S = 1 2 (p–φ)12– 1 2 (–cosφ)senφ Y X CT 1 1 S senq cosq φ S = 2p – 2φ + sen2φ 4 Clave D 05 AC = 2sena CB = 1 Área de la región ABCD: S = 1 2 (1)(2sena) Y X D B A S C 1 1O 1 a = sena Clave B 06 cosa – n n = 1 + cosa 1 n = cosa 2 + cosa Área de la región sombreada S = 1 2 1 + cosa 2 + cosa (1) CT Y X cosa – n 1 +cosa S 1 O45° 1 n a S = 1 +cosa 2 + cosa Clave B 07 1 –2x = –sena –x + cosa –x + cosa = 2xsena cosa = x(1 + 2sena) CT Y X –sena cosaQ(x;0) 1 2 1 2 1 a x = cosa 1 + 2sena Clave A 08 Área de la región triángularAMB: S = 1 2 ( 2) 1 + 2 2 S = 1 + 2 2 Y XB A M 1 2/2 2/2 2/2 ω ω S = 1 2 tan 3p 8 Clave B 09 MT = –secq – 1 Área de región AMT S = 1 2 (–secq – 1)(–senq) –sen q Y XA T M O1 1 1 A' P q S = 1 2 [tanq + senq] Clave D 10 n 1 – n = 1 –cosq n = 1 1 – cosq Área de la región APN S = 1 2 (1)(1) + 1 2 (1) 1 1 – cosq Y XA P N A H O 1 qsenq cosq 45° 1–n n n S = 1 2 2 – cosq 1 – cosq Clave C CUADERNO DE TRABAJO 01 sena < 0 AB = –sena Y XA O B Clave B 02 cosq < 0 PQ = –cosq Y X P Q Clave D 03 Tenemos OA = sena, OB =|senb| Luego, AB = OA + OB = sena +|senb|= sena – senb, pues b es un ángulo del ter- cer cuadrante. Clave C 04 Los BDO y CAO son congruentes, lue- go OC= OB. OC = –seca. Clave A 05 De la figura, los triángulo AOM y AHP son semejantes, luego: OM 1 = |senq| 1 +|cosq| OM = senq 1 – cosq Y X P O A1H M Clave A 06 OB =|cosa|, OD = sena OB = PD AD = AO + OD Y X P O A 1 B D AD = 1 + sena PA = cos2a + (1 + sena)2 PA = 2 + 2sena Clave B 07 Del gráfico, PQ = –sena Luego, área sombreada: 1 2 (PQ)(1) P B A' A B' Q O 1 – 1 2 sena Clave C 08 En la figura, OA = secq, BC = senq, OC = cosq. Área OAB = 1 2 secq · senq = 1 2 tanq Área OCB = 1 2 cosq · senq Área sombreada = 1 2 (tanq – cosq · senq) = 1 2 tanq(1 – cos2q) = 1 2 sen3q · secq m2 Clave A 09 De la figura: S 2p 3 sec , 0 = S(–2; 0) base = 1 m T cos , senp 3 p 3 = T 3 2 – 1 2 , altura = 3 2 m Área sombreada = 1 2 (base)(altura) 1 2 (1) 3 2 = 3 4 m2 Clave E 10 P(cosq, senq) Área de la región sombreada: S = –(cosq + senq) 2 m2 Y X O P 1 1 1 Clave B TAREA 01 AB = –cosa 02 EF = –sena EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 19 03 Área = 1 2 (2)(–senq) = –senq 04 Área = 1 2 (–cosq) = – cosq 2 REFORZANDO 01 AB = –senq Clave E 02 PQ = –cosa Clave D 03 OB = cosa OA = –cosβ AB = cosa – cosβ Clave B 04 5p 4 = p + p 4 X Y O (1; 0) cos 5p 4 sen 5p 4 P(a) a cos 5p 4 = cos p + p 4 = –cosp 4 = – 2 2 sen 5p 4 = sen p + p 4 = –senp 4 = – 2 2 P(a) = P – 2 2 ; – 2 2 Luego, la suma de coordenadas es: – 2 2 + – 2 2 = – 2 Clave B 05 Del gráfico se tiene que el área: = sena 2 = 2 4 a = 3p 4 Luego arco = 3p 4 Clave C 06 Área: 1 2 (2)(senq) = senq Clave A senq 2 –cosq 1 A B 0 X A' 1 1 A Y O senq q 07 Nótese que: OM = tan q 2 XA 1 A Y C qq/2 O M B Clave D 08 x2 + y2 =1 1 4 + b2 = 1 b = ± 3 2 ÁreaABO = 3 2 seca 2 = 3 4 seca µ2 Clave A 09 Del gráfico: a = 360° – (φ – β), OB = OA = 1µ Área del 9AOB: = 1 2 OA ⋅ OB ⋅ sena = 1 2 (1)(1) ⋅ sen(–(φ – β)) = – 1 2 sen(φ – β) Clave A 10 = 1 2 1 – – 3 2 + 1 2 = 1 4 + 3 4 Clave A 11 OC = OB = secq A = ABOC – AAOD = 1 2 qsec2q – 1 2 q(1)2 = q 2 (sec2q – 1) = q 2 tg2q Clave A 12 Coordenadas del punto P: – 4 5 ; 3 5 , C es una circunferencia unitaria AB = |tga| OA = CB = 1 Perímetro buscado: = 2 + 2 |tga|= 2 + 2 – 3 4 Aseca a O B – 1 2 ; b X A B Y O φa β X (0; 1) 1 (1; 0) Y 30° – 3 2 ; 1 2 3 2 1 2 S = 1 2 = 0 1 – 3 2 1 2 1 0 0 1 = 2 + 3 2 = 7 2 = 3,5 µ Clave A 13 X Y O A B C cosβ cosa a β Área del triángulo AOC = 1 2 (1)(–cosa) Área del triángulo OCB = 1 2 (1)(cosβ) Área buscada = 1 2 (cosβ – cosa) µ2 Clave C 14 De la figura: S sec 2p 3 ; 0 = S(–2; 0) base = 1µ T cos p 3 ; sen p 3 = T – 1 2 ; 3 2 altura = 3 2 µ Area sombreada = 1 2 (base)(altura) = 1 2 (1) 3 2 = 3 4 µ2 Clave E 15 AS = (–cosq) ⋅ 1 2 + senq ⋅ 1 2 AS = senq – cosq 2 AS = 2 ⋅ sen(q – 45°) 2 AS = Máximo [sen(q – 45°)]Max = 1 Por lo tanto el área máxima es = 2 2 µ2 Clave E ACTIVIDADES CAP 11 C.T. REPRESENTACIÓN DE SENO Y COSENO 01 sen70° > sen140° > sen50° > sen210° > sen300° Y X se n3 00 °sen210° se n7 0° se n5 0° sen140° Clave B X A' B B' A 1 –1 Y Y O senq cosq EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 20 02 cot70° > cos310° > cos130°> cos220° > cos160° Clave C 03 FVV Clave E 04 VVF Clave E 05 FVV Clave E 06 VFF Clave C 07 FFV Clave B 08 FVV Clave B 09 cosx < 3 2 cosx < 0,86 Y XO IVCIIIC ICIIC x 0,86 30° < x < 330° Por lo tanto la desigualdad presenta solu- ciones en los cuatro cuadantes. Clave E 10 x = p 6 = 30° y = 5p 6 = 150° Y X 5p 6 10p 6 p 6 y = x = z = B C FE A D z = 10p 6 = 300° senx = 1 2 ; cosx = 3 2 seny = 1 2 ; cosy = – 3 2 senz = – 3 2 ; cosz = 1 2 senx + seny + senz + cosx + cosy + cosz = 3 2 – 3 2 Clave A CUADERNO DE TRABAJO 01 El mayor es sen190° 260° 330° 190° 210° 230° Y X Clave A 02 El mayor es sen255°. 255° 240° 200° 300° 340° Y X Clave C 03 VFV. 0,5 5,10 1,52 4 1,57 4,71 3,14 6,28 Y X Clave B 04 El mayor es sen1. 0,4 0 0,8 11,57 4,71 3,14 4,8 5,5 Y X Clave A 05 I. (F) II. (F) III. (V) IV. (F) cosx cosx senx senx senx Y X Clave B 06 FFV Clave B 07 I. cos80° > cos100° II. cos200° < cos300° III. cos50° > cos70° >; <; > Clave C 08 –1 senq 1 –4 4senq 4 –5 4senq – 1 3 [–5; 3] Clave D 09 –1 < cosa < 0 –2 < 2cosa < 0 –1 < 2cosa + 1 < 1 Clave D 10 p 8 < x < 5p 24 p 4 < 2x < 5p 12 0 < 2x – p 4 < p 6 0 < sen p 4 2x – < 1 2 0 < 2sen p 4 2x – < 1 1 < 2sen p 4 2x – + 1 < 2 1 2 < 2sen p 4 2x – + 1 1 < 1 I 2; 4 Clave C TAREA 01 cos70° < cos310° < cos40° Y X 70° 40° 310° 02 sen100° 03 –1 senq 1 –10 10senq 10 –4 10senq + q 16 [–4; 16] 04 p < a < 3p 2 –1 < cosa < 0 3 > –3cosa > 0 3 > M > 0 REFORZANDO 01 OP = senq PB = 1 – senq Clave B 02 OP = –cosq A'P = 1 – (–cosq) = 1 + cosq Clave B 03 I. (V) II.(V) Clave A 04 I. (F) II.(F) Clave D 05 |cos160°|> sen160° –cos160° > sen160° 0 > sen160° + cos160° I. (F) sen160° < cos160° II.(F) Clave B 06 Y X 75° 100° 60° Y X X Y 340° 100° 190° 70° X Y 160° X Y 100° 200° 300° EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 21 • |cos200°|> |sen200°| • |sen100°|> |cos100°| • |cos300°|< |sen300°| I. (V) II.(V) III.(F) Clave C 07 –1 < cosβ < 0 –2 < 2cosβ < 0 –1 < 2cosβ + 1 < 1 –1 < L < 1 L ∈ 〈–1; 1〉 Clave E 08 I. senx1 > senx2 (V) II. cosx1 > cosx2 (F) III. 2p < 2x1 < 2x2 < 3p (F) sen2x1? sen2x2 Clave E 09 p 2 < x 2 < p x 2 ∈ IIC –1 < cos x 2 < 0 –3 < 3cos x 2 < 0 –4 < 3cos x 2 –1 < –1 L ∈ 〈–4; –1〉 Clave D 10 • 17p 24 x 21p 24 17p 12 – p 12 2x – p 12 21p 12 – p 12 4p 3 2x – p 12 5p 3 X Y 60° 60° – 1 2 cos 2x – p 12 1 2 1 L 5 Clave C 11 0 cos2 1 0 2cos2q 2 3 2cos2q + 3 5 A ∈ [3; 5] Clave A 12 X Y x1 p 2x1 2x1 sen2x1 senx2 senx1 sen2x2 sen2x2 sen2x2 cosx1 cosx2 x2 2x2 2x2 3p 2 X Y 100° cos100° sen100° cos250° cos340°sen200° 200° 290°250° I. (F) II.(F) III.(F) Clave E 13 –1 cosq < 0 ∨ 0 < cosq 1 secq –1 ∨ secq ≥ 1 2k – 3 5 –1 ∨ 2k – 3 5 ≥ 1 k –1 ∨ k ≥ 4 –1 –1 < k < 4 Clave C 14 11 12 x 35 12 11p 24 px 2 35p 24 11p 24 – p 8 px 2 – p 8 35p 24 – p 8 p 3 px 2 – p 8 4p 3 –1 cos px 2 – p 8 1 2 –4 4cos px 2 – p 8 2 –3 4cos px 2 – p 8 + 1 3 C ∈ [–3; 3] Clave B 15 I. (V) II. (V) III. (V) cosx2 < cosx1 Clave E ACTIVIDADES CAP 12 C.T. REPRESENTACIÓN DE TANGENTE Y COTANGENTE 01 tan5 <tan2 < tan3 < tan1 < tan4 Clave D 02 FFF Clave D 03 I-V ; II-F ; III-V Clave A X Y 60° 240° 1 2 – 1 2 X x2 x1 senx1 > senx2 Y p 2 X x2 x1 |cosx2| > |cosx1| Y 04 VFV Clave D 05 Área de la región TPA S = 1 2 (–tanq)(1) Y XtanqS 1M O A P T q S = – 1 2 tanq Clave C 06 I-V ; II-F ; III-V ; IV-V Clave D 07 I-F ; II-V ; III-F Clave B 08 Área de la región THO: S = 1 2 (–cosq)(–tanq) Y Xcosq tanq S 1 M O A H T q S = 1 2 senq Clave E 09 I-F ; II-F ; III-V Clave D 10 AD = 1 – cosq Área de la región ABCD S = 1 2 (senq + tanq)(1 – cosq) Y X senq cosq tanqM O D S A B C q S = tanqsen2q 2 Clave E CUADERNO DE TRABAJO 01 Se tiene: q > 0, a < 0 OA = 1, AT = tanq T(1; tanq) Y XA(1; 0) B(0; 1) D P O Q OB = 1, BC = cota C(cota; 1) = 1 + tanq + cota + 1 = 2 + tanq + cota Clave C 02 I. (V) II. (F) III. (V) tan135° = tan315° tan300° tan100° tan200° tan50°Y X Clave B 03 Expresando en función de la tangente: I. cot20° > cot50° (V) II. cot120° < cot160° (F) III. cot220° > cot260° (V) EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 22 co t2 60 ° co t1 60 ° co t1 20 ° co t5 0° co t2 20 ° co t2 0°Y X Clave C 04 tan1 > tan0,5 > tan3,5 > tan3 > tan2,5 tan3 tan2,5 2,5 0,51,57 4,71 3,5 3,14 1 3 6,28 0 tan3,5 tan0,5 tan1 Y X El mayor es tan1. Clave D 05 PQ 2 = sen(180° – q) PQ = 2senq PO = cosq Área = cosq · 2senq 2 = senq · cosq Clave D 06 A = 1 2 (–tanq) + 1 2 (–cotq) – p 4 4A = –2tanq – 2 cotq – p 4A + 2cotq = –2tanq – p Clave C 07 0 tan2x < 1 0 3tan2x < 3 1 3tan2x + 1 < 4 1 –1 Y X 1 L < 4 [1; 4 Clave D 08 Y X tanx1 tanx2 I. tanx1 < tanx2 (V) II. tanx1 < tanx2 (V) Y X tanx1 tanx2 x2 x1 Y X tanx1 tanx2 III.|tanx1|<|tanx2| (V) Clave A 09 Área de la región sombreada: = – 1(–tana) 2 – (–a) 2 + p 2 + a 2 = tana 2 + a 2 + a 2 + p 4 Y XO 1 = – tana 2 + a + p 4 m2 Clave B 10 AD = –cota AC = 1 + cosb ÁreaABC = – cota 2 (1 + cosb) = –cota · cos2 b 2 Clave C TAREA 01 X Y tan80° = c tan65° = b tan135° = a a < b < c 02 X Y tan160° tan140° tan110° tan105° = tan285° tan100° 03 Área = 1 · 1 2 + (1) – tanq 2 = 1 – tanq 2 04 Hallando el orden de las tangentes: tan200° < tan230° < tan260° 1 tan200° > 1 tan230° > 1 tan260° cot200° > cot230° > cot260° El mayor es cot200° REFORZANDO 01 El mayor es tan2p 5 Clave E 02 I. (F) II. (F) III. (V) Clave D I. (F) II. (F) III.(V) X1 1 Y –tanq tanqq X Y tan230° 230° tan260° 260° tan200° 200° X Y tan 2p/5 tan p/4 tan 2p/9 tan p/5 tan 2p/5 03 El menor es cot100° Clave C 04 I. (V) II. (F) III. (V) Clave C 05 Área = 1 2 (tanq – tana) Clave D 06 X1O N AA' T M 1 Y q –tanq –tanq 2 = ON 1 ON = –tanq 2 Área = 1 ⋅ ON 2 = – tanq 4 Clave C 07 a = –cosq b = 1 + cosq X a b Y (0; 1) (–cosq; – senq) cosq senq 1; tanq S2 S1 –tanq q S1 = 1(–cosq) 2 S2 = –tanq(1 + cosq) 2 S1 + S2 = 1 2 (–senq – cosq – tanq) = – 1 2 (senq + cosq + tanq) Clave A 08 Analizando la gráfica se tiene: a = cosa, b = sena, c = 0, d = csca, e = 1, f = tga X Y cot100° cot80° cot70° cot205°cot245° X Y cot290° cot310° cot50° cot40° cot190°cot210° X1 Y tanq a q –tana EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 23 Luego: bf + dc |ae| = sena ⋅ tga + 0 |cosa| = sen2a –cos2a = –tan2a Clave C 09 x = 1 2 tanq O x 1 1 tanq q A P M A' A = 1 ⋅ x 2 A = tanq 4 Clave C 10 O q – p 2 q A M N Q Y P AN = tan q – p 2 = cotq MQ = 1 – cos q – p 2 = 1 – senq S = 0,5 cotq(1 – senq) Clave C 11 I. (V) II. (F) III. (F) Clave D 12 F = tan2q – 1 + 2tanq = (tanq + 1)2 – 2 – 1 2 senq 2 2 – sen p 6 senq sen p 4 – p 6 q p 4 tan – p 6 tanq tan p 4 – 3 3 tanq 1 1 – 3 3 tanq + 1 2 (tanq + 1)2 4 (tanq + 1)2 – 2 2 F 2 FMAX = 2 Clave C 13 • CD = senq OD = cosq AB = tanq A = senq + tanq 2 (1 – cosq) A = senq 2 ⋅ sen2q cosq = tanqsen2q 2 Clave E O A B' (c; d) (e; f) (a; b) tga sena cosa AA' tanqsenq 1 – cosq 14 O 1 C AA' Y M T senq q P S = PM ⋅ PA 2 S = senq(1 – cosq) 2 Clave E 15 –1 ≤ cosa ≤ 1 – p 3 ≤ p 3 cosa ≤ p 3 cot – p 3 ≤ cot p 3 cosa ≤ cot p 3 – 1 3 ≤ cot p 3 cosa ≤ 1 3 0 ≤ cot2 p 3 cosa ≤1 3 Clave C ACTIVIDADES CAP 13 REDUCCIÓN AL PRIMER CUADRANTE I 01 F = –sena sena + –cosa cosa + tana tana F = –1 – 1 + 1 = –1 Clave A 02 K = tan17° + cot17° tan17° + cot17° (–tan17°) K = –tan17° Clave A 03 C = (–sen60°)tan45° (–cos60°)tan30° = 3 2 (1) 1 2 1 2 C = 2 3 Clave B 04 C = –sena sena + cosa cosa C = –1 + 1 = 0 Clave E 05 senq = –2cosq ⇒ tanq = –2 R = (–cotq)(–secq)(tanq) (–senq)(–cscq)(–cosq) = – secq cosq R = –sec2q = –[1 + tan2q] = –[1 + (–2)2] R = –5 Clave B 06 K = sen60°(–cos60°)(–tan60°) (–sec45°) K = – 3 2 1 2 3 2 = – 3 2 8 Clave D 07 J = (–cotx)(tanx)(–cscx) J = cscx Clave B 08 K = (–senx)(–cscx) + (–tanx)cotx K = 1 – 1 = 0 Clave E 09 ω q ω 1212 12 12 5 A'(–12;5) A(12;5) tanq = –5/12 Clave C 10 a = q + 180° tana = tan(180° + q) tana = –tanq q a B 3 A 2 2 C 37° tana = – 3/2 Clave D CUADERNO DE TRABAJO 01 E = cos p + p 9 –sen p + 2p 3 –cot 2p + 2p 9 cos p 9 –sen p 6 –cot 2p 9 E = –cos p 9 cos p 9 · –sen p + 2p 3 sen p 6 · cot 2p 9 cot 2p 9 E = (–1) · 1 2 3 2 – · 1 = 3 Clave E 02 cos170° = –cos10° cos150° = –cos30° cos130° = –cos50° cos110° = –cos70° cos90° = 0 cos10° + cos30° + ... + cos170° = 0 Clave E 03 L = (–cos45°)(–cot60°)(sec60°) (cos30°)(tan37°)(–tan60°) L = – 2 2 3 3 2 3 2 3 4 3 ⋅ ⋅ ⋅ ⋅ = – 9 3 3 8 2 3 = – 27 8 6 Clave C 04 E = 4 2 1 2 2 2 3 4 3 2 1 2 ( ) ( ) − = ( 3 – 1)( 3 + 1) 3( 3 + 1) EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 24 E = 2 3( 3 + 1) Clave B 05 E = –senx –senx – cotx –cotx + secx secx E = 1 + 1 + 1 = 3 Clave E 06 E = 2x2(cos60°) + 3 2 x(tan53°) + 2(sen30°) x(+tan45°) – (–1) E = 2x2 · 1 2 + 3 2 x · 4 3 + 2 · 1 2 x(1) – (–1) = (x + 1)2 x + 1 = x + 1 Clave D 07 sen(–q) – cosq –senq – sen(q) = –senq – cosq –2senq = 1 2 (1 + cotq) Clave B 08 tana = – a b (b; a) (a; b) Clave C 09 E = –2(–cotx) cotx(–secx)(–cosx) = 2 Clave E 10 E = +senx –senx · –senx –senx = –1 Clave E TAREA 01 L = (cos30°)(sen60°) cos225° L = (cos30°)(sen60°) –cos45° = 3 2 ⋅ 3 2 – 2 2 = –6 4 2 = – 3 2 4 02 Procedemos, por partes: • sen240° = –sen60° = – 3 2 • cos120° = –cos60° cos120° = – 1 2 Reemplazando: C = – 3 2 – 1 2 C = 3 03 Por partes: • tan225° = +tan45° tan225° = 1 • sen330° = –sen30° sen330° = – 1 2 Luego: C = 1 – 1 2 C = –2 04 tanq = – 5 –2 = 5 2 REFORZANDO 01 E = cos2x (–cscx)2 – 1 + (–senx)2 sec2x – 1 E = cosx2 cot2x + senx2 tan2x E = sen2x + cos2x E = 1 Clave C 02 E = –sen(180° + 20°) – cos(270° – 20°) sen(180° – 20°) E = – (–sen20°) – (–sen20°) sen20° E = 2sen20° sen20° = 2 Clave B 03 sena = sen(180°– 42°+q) ⋅ tan(270°+28°–q) 2sen(42° – q) ⋅ cot(q – 28°) sena = –sen(q – 42°)(–cot (28° – q)) 2sen(42° – q) ⋅ cot(q – 28°) sena = 1 2 y = 1 r = 2 ∧ x = – 3 E = 2 – 3 + 1 – 3 = 3 – 3 = – 3 Clave B 04 C = (–cos45°)⋅ (–sen60°) ⋅ (–cot60°) (–cos30°) ⋅ (sen30°) C = cos45° ⋅ cos30° ⋅ tan30° cos30° ⋅ sen30° C = cos45° cos30° = 2 2 3 2 = 6 3 Clave A 05 M = –sen60° ⋅ (–sen37°) ⋅ (sen45°)2 M = – 3 2 ⋅ –3 5 ⋅ 2 2 2 M = 3 3 20 = 0,15 3 Clave C X Y 3 3 2 2 q 5 (–2; – 5) 5 06 L = (–senx)(–cotx) ⋅ tan(2p – x) sen 3p 2 – x sen 3p 2 + x L = senx ⋅(cotx)(–tanx) –cosx ⋅ –cosx L = –secxtanx Clave D 07 A = (+cosx)(–tanx) tan(180° + x) (–cosx) 1 cos(360° – x) sen(270° + x) A = –cosx ⋅ tanx ⋅ tanx (–cosx) 1 cosx (–cosx) = –tan2x Clave E 08 P = cos(2p – x) ⋅ cos(p – x) ⋅ tan(2p + x) sen p 2 – x ⋅ 1 tan(p + x) ⋅ sen 3p 2 + x P = cosx ⋅ (–cosx) ⋅ tanx (cosx) ⋅ 1 tanx (–cosx) = tan2x Clave E 09 tan(–β) = – 3 4 –tanβ = – 3 4 tanβ = 3 4 Clave D 10 cotq = x y = – 4 1 = –4 Clave D 11 –sen(180° – x) cos(90° – x) = –senx senx = –1 Clave B 12 x = 180° – y ⇒ tanx = – tany y = 270° – z ⇒ tany = cotz M = (–tany)(coty) + (cotz)(tanz) M = –1 + 1 = 0 Clave A 13 • A + B + C = 180° B + C = 180° – A sen(B + C) = sen(180° – A) = senA E = senA + senA + sen(180°) E = 2senA Clave B 37° 3 1 4 4 (–4 ; 1) 1 4 4 X Y q EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 25 14 tanq = y x = – 3 7 Clave D 15 E = sec 3p 2 – a = –csca E = –1 sena = –1 – 4 5 = 5 4 (–3; –4) Y X 5 a Clave E ACTIVIDADES CAP 14 REDUCCIÓN AL PRIMER CUADRANTE II 01 tan2933° = tan(8(360°) + 53°) = tan53° tan2933° = 4 3 Clave C 02 E = sen180° + cos2180° cos4270° = 0 + (–1)2 (–1)4 E = 1 1 = 1 Clave A 03 C = senx cos(–x) + tan(–x) C = tanx – tanx = 0 Clave C 04 M = sen140° sen40° + cos20° cos160° M = sen40° sen40° + cos20° –cos20° = 1 – 1 = 0 Clave E 05 E = sen70°cos160°tan(–110°) cot20°sen(–70°)sec160° E = –cos20°tan70° –70°(–sec20°) = –cos220° Clave D 06 E = |sen(p + q)|+|tan(4p/3 + q)|+|tan(p/2 + q)| E = |sen150°|+|tan210°|+|sec60°| E = |sen30°|+|tan30°|+|csc30°| E = 1 2 + 3 2 + 2 = 6 15 + 2 3 Clave C 07 cos(90°+a)cos(270°–a)–sen(180°–a)sen(–a) –sena(–sena)–sena(–sena) sen2a+sen2a 2sen2a Clave A 3 3 (7; 3) (7; –3) 4 3 3 4 Y q 08 sen[1 + (–senq)] = – 1 senq – sen2q = –1 Calculamos la segunda expresión: 1 – (–senq) + cos2q 1 + senq + 1 – sen2q 2 + senq+ – sen2q = 2 – 1 = 1 Clave D 09 cos 3p 2 – x (–sen(10p – x)) + sen(3p – x)cos p 2 – x –senxsenx + senxsenx = 0 Clave E 10 sec cot 13p 2 + y – sec(tany) + sen(x – y) sec cot p 2 + y – sec(tany) + sen13p 2 sec(–tany) – sec(tany) + sen p 2 sec(tany) – sen(tany) + 1 = 1 Clave B CUADERNO DE TRABAJO 01 sen(1800° + 60°) = sen60° sen(1860°) = 3 2 Clave D 02 tan(14p – x) = tan(7(2p) – x) tan(14p – x) = tan(–x) tan(14p – x) = –tanx Clave B 03 E = (–sen300° – 2tan60°) sec30° E = (sen60° – 2tan60°)cos30° E = 3 2 – 2 3 3 2 ⇒ E = – 9 4 Clave B 04 E = a2sen p 2 + 2abcos2p – b2sen3p 2 b2tan2p – 4absen3p 2 + (a – b)2cos2p E = a2 + 2ab – b2(–1) b2(0) – 4ab(–1) + (a – b)2 = a2 + 2ab + b2 4ab + (a – b)2 E = a2 + 2ab + b2 a2 + 2ab + b2 = 1 Clave E 05 E = 2sen30° + tan45° + 2 3cos30° E = 2 1 2 + 1 + 2 3 · 3 2 = 1 + 1 + 3 = 5 Clave D 06 E = x2(sen30°) + xcos300° x – (–tan45°) = x2 2 + x 2 x + 1 = x 2 Clave C 07 E = cos – p 4 tan – p 4 sec – 2p 3 cot – 7p 6 sen – p 3 csc – p 6 E = 2 2 1 2 3 3 2 2 −( ) − ( )( ) = 2 3 Clave D 08 N = p 2 q –sec(q) · sen cot(p – q) · cos 3p 2 + q = sec(q) (–cosq) (–cotq) (senq) N = secq · 1 Ncosq = 1 Clave B 09 E = senq – tanq –cscq + cotq = sen p 3 – tan p 3 –csc p 3 + cot p 3 E = 3 2 3 2 3 3 3 3 − − + = 3 2 Clave D 10 H = tan(p + x) sen p 2 – x secx cot 3p 2 + x senx tan p 4 H = tanx · senx · secx –tanx · senx · (1) = –secx Clave B TAREA 01 • tan(2580°) = tan(360° ⋅ 7 + 60°) = tan60° = 3 02 • sen(36p + x) = sen(18(2p) + x) = senx 03 • cos(14p – x) cos(7(2p) – x) = cos(–x) = cosx 04 • cot2580° cot(360° ⋅ 7 + 60°) = cot60° = 3 3 REFORZANDO 01 • cos(4005°) cos(360° ⋅ 11 + 45°) = cos45° = 2 2 Clave E EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 26 02 L = sen(24p + x) sen(14p – x) L = sen(x) sen(– x) = senx –senx = –1 Clave B 03 U = (2sec120° – 1) ⋅ (2sen143° – 1) 2cos240° – 1 U = (2(–2) – 1) ⋅ (2 3 5 – 1) 2 –1 2 – 1 = (–5) ⋅ 1 5 –2 = 1 2 Clave A 04 cos 157p 11 = cos 14p + 3p 11 = cos 3p 11 Como: cos 157p 11 ∈ IIC = cos p – 8p 11 = – cos 8p 11 Clave C 05 • sen87p + 4 ⋅ cosp + 5 ⋅ sec 2p 0 –1 1 – 4 + 5 = 1 Clave C 06 tan 941p 4 = tan 234p + 5p 4 = tan 5p 4 = 1 cot 199p 4 = cot 50p – p 4 = –cot p 4 = –1 E = 1 – 1 = 0 Clave C 07 csc 9p 2 + q + cot 11p 2 + q = 1 2 IIC IVC secq + (–tanq) = 1 2 secq – tanq = 1 2 Clave C 08 cos 2p 7 + cos 4p 7 + cos 6p 7 = sen 3 2 × 2p 7 sen 1 2 × 2p 7 = cos 2p 7 + 6p 7 1 2 = sen 3p 7 sen p 7 ⋅ cos 4p 7 = –2sen 3p 7 ⋅ cos 3p 7 2sen p 7 = –sen 6p 7 2sen 6p 7 = – 1 2 Clave A 09 a2⋅csc(90°)+4ab sen30°⋅cos(180°)+b2 sen90° a sec2180°⋅tan260°+b tan(–60°)⋅cot30° a2 + 4ab 1 2 (– 1) + b2 a(–1)2( 3)2 + b( 3)( 3) (a – b)2 3(a – b) = a – b 3 Clave D 10 P = sen p 6 + cos 2p 3 + tan p 4 P = 1 2 – cos p 3 + 1 P = 3 2 – 1 2 = 1 Clave B 11 sen 7p 12 cos p 12 + sen p 12 cos 7p 12 cos p 12 cos p 12 + sen p 12 –sen p 12 = 1 – 1 = 0 Clave A 12 G = 2tan(p + q) + 3cot p 2 – q 4sen(–q) + 5cos 3p 2 + q G = 2(tanq) + 3tanq –4senq + 5(senq) = 5tanq senq G = 5secq Clave C 13 • a ∈ IV cuadrante tana = 8sen(p – a) cos(– a) csc p 2 + a tana = 8sena ⋅ cosa seca sena cosa = 8sena ⋅ cosa seca sec3a = 8 seca = 2 Clave E 14 G p 8 = cot 9p 8 – tan 46 3 p 8 + 2sen 16 3 p 8 + sec10 p 8 = cot p 8 + tan p 12 + 2sen 2p 3 – sec p 4 = 2 + 1 + 2 – 3 + 2 3 2 – 2 G p 8 = 3 Clave E 15 E = sen –p 3 ⋅ cot p 4 = – 3 2 ⋅ (1) E = – 3 2 Clave B ACTIVIDADES CAP 15 IDENTIDADES TRIGONOMÉTRICAS FUNDAMENTALES 01 M = cosx senx senx 2 + senx cosx cosx 2 M = cos2x + sen2x = 1 Clave A 02 W = (1 – cos2x)senx (1 – sen2x)cosx 3 = sen3x cos3x 3 W = senx cosx = tanx Clave D 03 senx + 1 – cos2x = 1 ⇒ senx = cos2x E = 1 + tan2x – 1 = tan2x = sen2x cos2x E = sen2x senx = senx Clave E 04 E = 2sen2x – sen2x – cos2x E = (sen2x – cos2x)(sen2x + cos2x) 1 E = sen4x – cos4x Clave B 05 secx = tany = 7 P = 1 + tan2y – sec2x + 1 P = 1 + 72 – 72 + 1 = 2 Clave A 06 senx cosx + cosx senx = sen2x + cos2x senx · cosx = 4 1 = 4senxcos ⇒ senxcosx = 1 4 C = 1 4 Clave B 07 L = sec2x – tan2x – 1 + 2tanx L = 1 – 1 + 2tanx = 2tanx Clave D 08 (senx + cosx)(sen2x + cos2x – senxcosx) (senx + cosx) = 7 8 1 – senxcosx = 7 8 ⇒ senxcosx = 1 8 M = sen2x + cos2x senxcosx = 1 1 8 = 8 Clave E 09 9sen2x + cos2x + 6senxcosx = m2 ... (I) sen2x + 9cos2x – 6senxcosx = n2 ... (II) (I) + (II): 10(sen2x + cos2x) = m2 + n2 m2 + n2 = 10 Clave B EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 27 10 R = 3(2(sec2x + tan2x)) sec2x – tan2x= 6(1 + tan2x + tan2x) 1 R = 6 + 12tan2x = 6 + 12(cotx)–2 a + 3b(cotx) – c = 6 + 3(4)(cotx)–2 a = 6 ; b = 4 y c = 2 a + b + c = 12 Clave B CUADERNO DE TRABAJO 01 E = (sen2a + cos2a)2 cos2a = 1 cos2a = sec2a Clave A 02 sena(1 – sen2a) cosa = sena cos2a cosa = sena cosa Clave A 03 L = (senx – cosx)(senx + cosx)(sen2x + cos2x) (senx – cosx) – cosx L = (senx + cosx)(sen2x + cos2x) 1 – cosx L = senx + cosx – cosx = senx Clave C 04 senx cosx + senx = 2(1 + cosx) senx(1 + cosx) cosx = 2(1 + cosx) tanx = 2 (x III C) secx = – 5, cscx = 2 5– C = (– 5) 2 5– = 5 2 Clave B 05 E = (secq – 1)(1 + cosq)cosq sen2q E = sen2q 1 cosq (1 + cosq)cosq– 1 E = (1 – cos2q)cosq sen2q cosq = sen2q cosq sen2q cosq = 1 Clave A 06 E = cos2x(4cos2x – 1) sen2x(3 – 4sen2x) = cos2x(4cos2x – 1) sen2x(3 – 4(1 – cos2x)) E = cos2x(4cos2x – 1) sen2x(4cos2x – 1) = cot2x Clave E 07 • sec2x – secx – 1 = 0 (1 + tan2x) – secx – 1 = 0 sen2x cos2x = 1 cosx cosx = sen2x • M = cosx – cos2x sen2x M = cosx – cos2x cosx M = cosx – cosx = 0 Clave E 08 1 cos2x = n senx cosx senx cosx = 1 n (senx – cosx)(sen2x + senx cosx + cos2x) (senx – cosx)(sen2x – 2senx cosx + cos2x) 1 + senx cosx 1 – 2senx cosx = 1 + 1 n 1 – 2 n = n + 1 n – 2 Clave C 09 1 cosx + 1 senx = m senx + cosx senx cosx = m (I) senx + cosx = n 1 + 2senx cosx = n2 (II) De (I): n senx cosx = m senx cosx = n m En (II): 1 + 2n m = n2 2n m = n2 – 1 2n = m(n2 – 1) Clave D 10 E = a(sen2x ) 1 2 – bsenx a(1 + sen2x + cos2x + 2senx – cos2x) 1 2 – a 1 E = asenx – bsenx a(1 + senx) – a = asenx – bsenx asenx = a – b a Clave D TAREA 01 E = senx 1 senx + cosx 1 cosx + tanx 1 tanx E = sen2x + cos2x + tan2x 1 E = 1 + tan2x = sec2x 02 E = (1 + cosx) 1 senx – cosx senx E = (1 + cosx) (1 – cosx) senx E = 1 – cos2x senx = sen2x senx = senx 03 1 E = sen2x + cos2x + 2senx cosx – 1 senx cosx E = 2senx cosx senx cosx = 2 04 cosx 1 1 + senx + 1 1 – senx = 2 k cosx 2 1 – sen2x = 2 k cosx 2 cos2x = 2 k k = cosx REFORZANDO 01 4 senx cosx + cosx senx cosx senx – 4sen2x = 4 1 cosx senx cosx senx – 4sen2x = 4(1 – sen2x) = 4cos2x Clave E 02 sec2x – tan2x + 2senx cosx 1 = sen2x + cos2x + 2senx cosx = (senx+cosx)2 = (0,3)2 = 0,09 Clave C 03 sen2x csc4x + cos2x sec4x – sen6x = sen6x + cos6x – sen6x = cos6x Clave C 04 (tan2x + 1)2 sec4x = (sec2x)2 sec4x = 1 Clave B 05 cosx senx – 1 + senx + 1 sen2x – 1 = cosx(2senx) –cos2x = –2tanx = –10 Clave E 06 sec2a – tg2a – 2 1 tga + tga – cosa = 1 + 2 cosa sena + sena cosa – cosa = 1 + 2sena ⋅ cosa – cosa = (sena + cosa)2 – cosa = (sena + cosa) – cosa = sena Clave A 07 tan4a + 2tan2a cot2a + cot4a = 34 + 2 (tan2a + cot2a)2 = 36 tan2a + cot2a = 6 sec2a – 1 + csc2a – 1 = 6 sec2a csc2a = 8 sen2a cos2a = 1 8 Clave B 08 2A = tg3β – ctg3β sec2β ⋅ csc2β – 1 = (tgβ – ctgβ)(tg2β + tgβ ⋅ ctgβ + ctg2β) sec2β ⋅ csc2β – 1 = (tgβ – ctgβ)(sec2β – 1 + 1 + csc2β – 1) sec2β ⋅ csc2β – 1 = (tgβ – ctgβ)(sec2β ⋅ csc2β – 1) sec2β ⋅ csc2β – 1 = tgβ – ctgβ 2A = B B A = 2 Clave E EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 28 09 [(sen10° + cos10°) + 1][(sen10° + cos10°) – 1] – sen10° ⋅ cos10°= (sen10° + cos10°)2 – 12 – sen10° ⋅ cos10° = = sen210° + cos210° + 2sen10° ⋅ cos10° – 1 – sen10° ⋅ cos10° = 1 + 2sen10° ⋅ cos10° – 1 – sen10° ⋅ cos10° = sen10° ⋅ cos10° Clave E 10 E = (1 + ctg2x) – 10ctgx = (ctg2x – 10ctgx + 52) – 24 = (ctgx – 5)2 – 24 Como: (ctgx – 5)2 ≥ 0 (ctgx – 5)2 – 24 ≥ – 24 Min = 0 E ≥ – 24 Emin = – 24 Clave D 11 sec225° sen225°+cos225°+2sen25°⋅cos25° 1 cos25° + 1 sen25° = sec225° (sen25°+cos25°)2 sen25° + cos25° sen25° ⋅ cos25° = sen25° + cos25° sen25° + cos25° ⋅ sen25° ⋅ cos25° ⋅ sec225° = sen25° ⋅ cos25° ⋅ sec225° = sen25° cos25° = tg25° Clave D 12 senx (1 – secx) = –2cosx sen2x (1 – 2secx + sec2x) = 4cos2x 1 – 2secx + sec2x = 4ctg2x sec2x – 4cot2x 1 – 2secx = –1 Clave C 13 • k = secx – tanx 1 tanx – 1 secx = secx – tanx secx – tanx secx tanx k = secx tanx • De la condición: 1 = tan3x + tanx 1 = tanx (tan2x + 1) 1 = tanx sec2x 1 = tanx secx k = 1 Clave D 14 cosx (1 – senx) secx – tgx ⋅ secx + tgx secx + tgx = cosx (1 – senx)(secx + tgx) sec2x – tg2x = cosx 1 + senx cosx (1 – senx) 1 = 1 – sen2x = cos2x Clave B 15 Sea: secx = a tan2x = a2 – 1 Reemplazando: a2 + a4 + a2 (a2 – 1) + (a2 – 1)3 a3 + (a2 – 1) = a2 + a4 + a4 – a2 + a6 – 3a4 + 3a2 – 1 a3 + a2 – 1 = a2 + a 6 – (a4 – 2a2 + 1) a3 + a2 – 1 = a4 + a 6 – (a2 – 1)2 a3 + a2 – 1 = a2 + [a3 + (a2 – 1)][a3 – (a2 – 1)] a3 + a2 – 1 = a2 + a3 – a2 + 1 = a3 + 1 = sec3x + 1 ≡ secM(x) + N M + N = 3 + 1 = 4 Clave C ACTIVIDADES CAP 16 IDENTIDADES TRIGONOMÉTRICAS AUXILIARES 01 secxcscx = 3 J = sec2x + csc2x + 2secxcscx J = sec2xcsc2x + 2(3) J = (3)2 + 6 = 15 Clave D 02 R = secqcscq + 2 secqcscq – senq R = 1 + 2senqcosq – senq R = (senq + cosq)2 – senq R = senq + cosq – senq = cosq Clave B 03 sec2x – tan2x = 1 ; secx – tanx = 2 (secx + tanx)(secx – tanx) = 1 (secx + tanx)(2) = 1 ⇒ secx + tanx = 1 2 Sumando: 2secx = 5 2 ⇒ secx = 5 4 Clave B 04 sec2xcsc2x = 2cot2xsec3x 1 sen2x = 2 cos2x sen2x · 1 cosx cosx = 1 2 x = 60° ∨ 300° Clave E 05 secxcscx = 4 ⇒ senxcosx = 1 4 J = 1 – 3sen2xcos2x = 1 – 3 1 4 2 = 13 16 Clave E 06 sen4β + cos4β = 1 – cos4β 1 – 2sen2βcos2β = (1 –cos2β)(1 + cos2β) 1 – sen2β = 3sen2βcos2β 1 3 = sen2β senβ = 1 3 3 2 1 tanβ = 1 2 ⇒ tan2β = 1 2 Clave D 07 1 + 2senxcosx = 4 3 ⇒ senxcosx = 1 6 J = 1 senxcosx = 1 1 6 ⇒ J = 6 Clave B 08 senx + cosx = 1 3 1 + 2senxcosx = 1 9 senxcosx = – 4 9 J = 1 + senx + cosx + senxcosx J = 1 + 1 3 + – 4 9 = 8 9 Clave E 09 (sec2x –tan2x)2 = (1)2 sec4x + tan4x – 2sec2xtan2x = 1 a + bsec2xtan2x = 1 + 2sec2xtan2x a = 1 ; b = 2 2a + b = 2(1) + 2 = 4 Clave C 10 1 – 2sen2xcos2x = m ... (I) 1 + 2senxcosx = n2 senxcosx = n 2 – 1 2 ... (II) (II) en (I): 1 – 2 n 2 – 1 2 2 = m 2(1 – m) = (n2 – 1)2 Clave E CUADERNO DE TRABAJO 01 J = (tanx + cotx – cotx)cscx J = tanx · cscx = senx cosx · 1 senx = secx Clave B 02 E = 1 – 2sen2x cos2x – 1 1 – 3sen2x cos2x – 1 = –2sen2x cos2x –3sen2x cos2x E = 2 3 Clave C 03 C = (tanx + cotx – cotx)(tanx + cotx – tanx) C = tanx · cotx = 1 Clave A 04 secx · cscx = cotx + 1 tanx + cotx = cotx + 1 tanx = 1 x {45°; 225°} Clave E EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 29 05 senx cosx + cosx senx = 2 2 sen2x + cos2x senx cosx 1 = 2 2 senx · cosx = 1 22 = 2 4 J = 1 – 2sen2x · cos2x J = 1 – 2 2 4 2 = 1 – 1 4 = 3 4 Clave C 06 A = csc2x(sec2x – 1) sec2x(csc2x – 1) = csc2x · tan2x sec2x · cot2x A = cos2x sen2x · tan2x cot2x = cot2x · tan2x cot2x = tan2x Clave B 07 senx cosx + cosx senx = n senx cosx = 1 n (senx + cosx)2 = m2 1 – 2senx cosx = m2 1 + 2 1 n = m2 2 n = m2 – 1 n(m2 – 1) = 2 Clave A 08 • senx + cosx = m 1 + 2senx cosx = m2 senx cosx = m 2 – 1 2 • E = 1 + (senx + cosx) + senx cosx E = 1 + m + m 2 – 1 2 = 0,5(m + 1)2 Clave E 09 [sec8x – sec6x + sec4x – sec2x]csc2x [sec6x(sec2x – 1) + sec2x(sec2x – 1)]csc2x sec2x(sec2x – 1) [sec4x + 1]csc2x sec2x · tan2x [sec4x + 1]csc2x sec2x · sen2x cos2x [sec4x + 1] · 1 sen2x sec4x(sec4x + 1) = sec8x + sec4x sec8x + sec4x = secMx + secNx M + N = 12 Clave B 10 (secx+ tanx)2 = m2 sec2x + tan2x + 2secx tanx = m2 (sec2x + tan2x)2 = (m2 – 2n)2 sec4x + tan4x + 2sec2x tan2x = m4 – 4m2n + 4n2 1 + 4sec2x tan2x = m4 – 4m2n + 4n2 1 + 4n2 = m4 – 4m2n + 4n2 4m2n = m4 – 1 Clave C TAREA 01 E = (secx ⋅ cscx)cosx E = (secx ⋅ cosx)cscx E = cscx 1 02 Si secx – tanx = 2 secx + tanx = 1 2 2tanx = – 3 2 ↑ (–) tanx = – 3 4 03 E = 2(1 – 3sen2x cos2x) – 3(1 – 2sen2xcos2x) E = 2 – 6sen2x cos2x – 3 + 6sen2x cos2x E = – 1 04 M = (sec2x + csc2x – sec2x) ⋅ sen2x M = csc2x ⋅ sen2x = 1 REFORZANDO 01 sen4x + cos4x = 1 – 2sen2x cos2x sen4x + cos4x = 1 – 2 1 4 2 = 7 8 Clave A 02 sen2x csc4x + cos2x sec4x – 3sen4x = sen6x + cos6x – 3sen4x = 1 – 3sen2x cos2x – 3sen4x = 1 – 3sen2x (1 – sen2x) – 3sen4x = 1 – 3sen2x + 3sen4x – 3sen4x = 1 – 3sen2x Clave E 03 secx + tanx = 3 4 secx – tanx = 4 3 1 cosx – senx cosx = 4 3 1 – senx cosx = 4 3 Clave D 04 • tanx + cotx = 3 2 senx cosx + cosx senx = 3 2 1 senx cosx = 3 2 senx cosx = 2 3 • sen6x + cos6x = 1 – 3 sen2x + cos2x = 1 – 3 2 3 2 = – 1 3 Clave A 05 1senx + 1cosx = 2 y 12 + 12 = 2 senx = cosx = 1 2 x = 45° tanx + cotx = 1 + 1 = 2 Clave C 06 • senx = 2 3 2 3 x 5 cosx = 5 3 • sen6x + cos6x = 1 – 3 sen2x cos2x sen6x + cos6x = 1 – 3 2 3 2 5 3 2 = 1 – 20 27 = 7 27 Clave B 07 M = sec2x + 2secx cscx + csc2x secx cscx – secx cscx M = sec2x csc2x + 2secx cscx secx cscx – secx cscx M = secx cscx + 2 – secx cscx = 2 Clave D 08 3sen4x – 2sen6x + 3cos4x – 2cos6x = 3(sen4x + cos4x) – 2(sen6x + cos6x) = 3(1 – 2sen2x cos2x) – 2(1 – 3sen2x cos2x) = 3 – 6sen2x cos2x – 2 + 6sen2x cos2x = 1 Clave B 09 Si cscx + cotx = 3 x + 1 cscx – cotx = x + 1 3 Del dato: cscx – cotx = 2x – 2 3 x + 1 3 = 2x – 2 3 x = 3 Clave C 10 3 senx + 2 cosx = 5 se observa que: ( 3)2 + ( 2)2 = ( 5)2 senx = 3 5 y cosx = 2 5 Sea: E = 1 + 3 5 1 + 2 5 (1 – senx – cosx)6 E = 1 + 3 5 1 + 2 5 2(1 – senx)(1 – cosx) E = 1 + 3 5 1 + 2 5 2 1 – 3 5 1 – 2 5 E = 2 1 – 3 5 1 – 2 5 = 12 25 Clave B 11 sec2x + csc2x = sec2x csc2x sec2x + csc2x = 1 (senx cosx)2 sec2x + csc2x = 1 1 n 2 = n2 Clave C 12 (senx + cosx)2 = 1 + 3 2 2 1 + 2senx ⋅ cosx = 4 + 2 3 4 senx ⋅ cosx = 3 4 Luego: 16(sen6x + cos6x) + 3(sec2x + csc2x) = 16[1 – 3sen2x ⋅ cos2x] + 3sec2x ⋅ csc2x EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 30 = 16 1 – 9 16 + 3 16 3 = 16 7 16 + 3 16 3 = 7 + 16 = 23 Clave D 13 senx + 2cosx = 3 1senx + 2cosx = 3 Se observa: 12 + ( 2)2 = ( 3)2 senx = 1 3 y cosx = 2 3 sec2x + csc2x = sec2x csc2x sec2x + csc2x = 3 2 + 3 = 9 2 Clave E 14 Multiplicando por senx la condición: 3senx + 7 = 2cosx – 3senx + 2cosx = 7 Se observa: (– 3)2 + 22 = ( 7)2 senx = – 3 7 y cosx = 2 7 Reemplazando: – 7 3 4 + 2 – 7 3 2 + 7 2 4 + 2 7 2 2 = 91 9 + 105 16 = 2401 144 = 49 12 Clave E 15 k = 1 – 2sen6x sen2x (1 – sen2x) k = 1 – 2sen6x sen2x cos2x De la condición: 1 cos4x – sen2x cos2x = 2cos2x 1 – cos2x sen2x = = 2cos6x 1 – cos2x sen2x = 2(1–3sen2x cos2x–sen6x) 1 – 2sen6x = 5sen2x cos2x 1–2sen6x sen2x cos2x = 5 k = 5 Clave E ACTIVIDADES CAP 17 IDEN. TRIGON. FUNDAMENTALES DE SUMA Y DIFERENCIA 01 L = senxcosa senxcosa = tanx Clave A 02 a = ω – q tana = tanω – tanq 1 + tanωtanq q a ω a 1 23 2 tana = 1 + 3 2 1 5 3 2 – 1 5 = 1 Clave A 03 3q = 2q + q sen2q + cos2qtanq + cos2qcotq – sen2q cos2q(tanq + cotq) cos2q(2csc2q) 2cot2q Clave A 04 cosxcosy + senxseny = 3senxseny cosxcosy = 2senxseny tanxtany = 1 2 Clave C 05 y = cos(a + 45°) + [–sen(45° – a)] (a + 45°) + (45° – a) = 90° y = cos(a + 45°) – cos(a + 45°) y = 0 Clave D 06 L = 1 + tan40°tan5° + tan40° + tan5° tan(45° – 5°) = tan45° – tan5° 1 + tan45°tan5° tan40° = 1 – tan5° 1 + tan5° tan40°tan5° + tan40° + tan5° = 1 Reemplazando: L = 1 + 1 L = 2 Clave B 07 a – 3q = (a + 2β) – (3q + 2β) tan(a – 3q) = 2 – 7 1 + 2(7) = – 1 3 Clave D 08 a + 53° 2 = 45° a = 37° 2 tana = 1 3 45° 53°/2 5 2 E 5 5 B 5 a D C Clave B 09 Propiedad: x + y + z = 180° tanx + tany + tanz = tanxtanytanz Aplicando: 1 + tanatanβtanγ = 1 + tana + tanβ + tanγ 1 + tanatanβtanγ = 1+ 2013 = 2014 Clave A 10 E = cotAcotB + 1 + cotBcotaC + 1 + cotAcotC + 1 E = 3 + (cotAcotB + cotBcotC + cotAcotC) 1 E = 3 + 1 = 4 Clave E CUADERNO DE TRABAJO 01 sena cosb + cosa senb + sena cosb – cosa senb cosa cosb – sena senb + cosa cosb + sena senb 2sena cosb 2cosa cosb = tana Clave A 02 sen50°sen10°x – sen50°cos10°y = –1 sen50°sen10°x + sen10°cos50°y = 1 (–) y(sen10°cos50° + sen50°cos10°) = 2 ysen(10° + 50°) = 2 y 3 2 = 2 y = 3 4 y = 3 34 Clave A 03 tan(q + a) = tanq + tana 1 – tanq tana 2 = tan tan θ θ + − 1 2 1 2 2 1 3 tanq = 3 4 Clave D 04 tan x 7 = tan tan tan tan 4 3 4 3 x x x x 7 7 1 7 7 − + ⋅ = a – b 1 + ab tanx = tan tan tan tan 4 3 4 3 x x x x 7 7 1 7 7 + − ⋅ = a – b 1 – ab E = (1 – a2b2) a – b 1 + ab a – b 1 – ab = a2 – b2 Clave B 05 N = sen4a sen2a cos4a cos2a – 2 – tan22a N = sen4a cos2a – cos4a sen2a sen2a cos2a 2 – tan22a N = sen(4a – 2a) sen2a cos2a 2 – tan22a N = sec22a – tan22a = 1 N2 – 1 = 0 Clave C 06 • tan(x – y) = a – b a + b • tan(y – z) = 1 Siendo x – y + y – z = x – z tan(x – z) = tan(x – y) + tan(y – z) 1 – tan(x – y) · tan(y – z) tan(x – z) = a b a b a b a b − + + − − + 1 1 = a b cot(x – z) = b a Clave B 07 C = 3senx + 4cosx 32 + 42Máx = + 5 = 10 L = 1senx + 3cosx 312 + 2 Mín = – + 1= –1 10 + (–1) = 9 Clave C 08 tana = 2k; tanb = 3k; tanq = 5k Como a + b + q = 90° tana tanb + tanb tanq + tanq tana = 1 6k2 + 15k2 + 10k2 = 1 EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 31 k = 31 1 tanq = 31 5 cotq = 31 5 Clave D 09 k = 2cotA tanB + tanB tanB + 2cotB tanC + tanC tanC + 2cotC tanA + tanA tanA k = 3 + 2(cotA cotB + cotB cotC + cotC cotA) k = 3 + 2(1) = 5 Clave B 10 Del gráfico: tanb = 1 7 ; tan(a + b) = 2 7 ; 53° 43 3 1 1 1 tan(a + b + q) = 3 4 tan(a + b – b) = 2 7 – 1 7 1 + 2 7 · 1 7 = 7 51 tana = 7 51 tan(a + b + q – a – b) = 3 4 – 2 7 1 + 3 4 · 2 7 = 13 34 tanq = 13 34 1 – tanq 3tana = 21 51 21 34 = 51 34 = 3 2 Clave A TAREA 01 R = sen30°cosx + senxcos30° + sen30°cosx – senxcos30° R = 2sen30°cosx = 2 1 2 cosx R = cosx 02 V = cos45°cosx – sen45°senx + cos45°cosx + sen45°senx V = 2 2 2 cosx = 2cosx 03 tan(x + y) = tanx + tany 1 – tanxtany tan(x + y) = 2 + 3 1 – 2(3) = –1 04 tan(45° – 37°) = tan45° – tan37° 1 + tan45°tan37° tan8° = 1 + 1 3 4 1 – 3 4 = 1 7 REFORZANDO 01 senx = 1 2 1 2 x 3 cosy = 1 3 3 1 y 8 sen(x + y) = senx cosy + seny cosx sen(x + y) = 1 2 ⋅ 1 3 + 8 3 ⋅ 3 2 = 1 + 2 6 6 Clave E 02 tan(30° – x) = tan30° – tanx 1 + tan30° tanx tan(30° – x) = 3 3 – 3 1 + 3 3 ⋅ 3 = – 2 3 6 = – 3 3 Clave E 03 sen(x + y) sen(x – y) + cos2x + sen2y sen2x – sen2y + cos2x + sen2y = 1 Clave B 04 sen(x – y) cosx cosy + tany + tanx tanx – tany + tany + tanx = 2 tanx Clave C 05 cosx = cosy cosz y + z = p – x cos(y + z) = cos(p – x) cos(y + z) = –cosx cosy cosz – seny senz = –cosy cosz 2cosy cosz = seny senz coty cotz = 1 2 Clave D 06 tanφ = – 3 2 X (2; –3) (–2; 1) β aa – φ Y tanβ = – 1 2 φ – a = β a = φ – β tana = tan(φ – β) = – 3 2 – – 1 2 1 + – 3 2 – 1 2 = – 4 7 Clave C 07 • tana tanβ = 7 18 sena cosβ cosa senβ = 7 18 sena cosβ = 7k cosa senβ = 18k • sen(a + β) = 4 5 sena cosβ + senβ cosa = 4 5 k = 4 125 7k 18k • 25sen(β – a) = 25(senβ cosa – sena cosβ) 18k 7k 25sen(β – a) = 25 ⋅ 11k = 25 ⋅ 11 ⋅ 4 125 = 8,8 Clave D 08 • tan70° – tan20° = 2a cot20° – tan20° = 2a 2cot40° = 2a tan40° = 1 a • sen5° = sen(45° – 40°) sen5° = sen45° cos40° – sen40° cos45° sen5° = 1 2 (cos40° – sen40°) = 1 2 a a2 + 1 – 1 a2 + 1 = a – 1 2a2 + 2 Clave D 09 • Valor máximo: (2n)2 + (n2 – 1)2 = 5 4n2 + n4 – 2n2 + 1 = 25 n4 + 2n2 + 1 = 25 (n2+1)2 = 25 n2 + 1 = 5 n2 = 4 n = 2 • Máximo valor pedido: = (12 n–1)2 + 102 n2 = 144 2–1 + 100 4 = 169 = 13 Clave C 10 M = (cot40° – tan40°) – tan10° tan(180° + 10°) M = (2cot80°) – tan10° tan10° = 2tan10° – tan10° tan10° = 1 Clave E 11 Aplicamos la identidad auxiliar: sen(a – β) cosa cosβ = tana – tanβ k = (tan27° – tan2x) + (tanx – tan27°) +(tan2x – tanx) k = 0 Clave A 12 Del gráfico: tana = 2 x tanβ = 8 x tan(a + β) = 12 x En la identidad: tan(a + β) = tana + tanβ 1 – tana tanβ 12 x = 2 x + 8 x 1 – 2 x ⋅ 8 x 12 x 1 – 16 x2 = 10 x 16 x2 = 1 6 x = 4 6 Clave B 13 De i) cota cotβ = 2cosa cotβ (cota + cotβ) cosa sena ⋅ cosβ senβ = 2cosa cosβ sen(a + β) sena senβ sen(a + β) = 1 2 De ii) (1 – sen2a) – (1 – sen2β) = 1 3 sen2β – sen2a) = 1 3 sen(β – a) sen(β + a) = 1 3 1 40° a a2 + 1 EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 32 sen(β – a) ⋅ 1 2 = 1 3 sen(β – a) = 2 3 sen(a – β) = – 2 3 Clave A 14 Obsérvese que: p 5 – q + p 20 + q = p 4 p 5 – q = p 4 – p 20 + q Dato: tan p 20 + q = 2 3 tan p 5 – q = tan p 4 – p 20 + q tan p 5 – q = tan p 4 – tan p 20 + q 1 + tan p 4 tan p 20 + q tan p 5 – q = 1 – 2 3 1 + 1 ⋅ 2 3 = 1 5 Clave A 15 De la condición: sen(q–β) tana = 2cosq cosβ sen(q–β) cosqcosβ = 2tana tanq = tanβ + 2tana (1) En la expresión: k = sen(q – a) cosq cosa sen(a + β) cosa cosβ = tanq – tana tana + tanβ k = tanβ + 2tana – tana tana + tanβ = tanβ + tana tana + tanβ = 1 Clave D ACTIVIDADES CAP 18 IDENTIDADES TRIGONOMÉTRICAS DE ÁNGULO DOBLE 01 sena = – 3 5 ; a ∈ IIIC 3cos2a = 3(1 – 2sen2a) 3cos2a = 3 1 – 2 – 3 5 2 = 21 25 Clave B 02 E = 1 2 2sen p 12 cos p 12 + 3 2 2sen p 6 cos p 6 E = 1 2 sen p 6 + 3 2 sen p 3 E = 1 2 1 2 + 3 2 3 2 = 1 Clave C 03 2cos22a – 1 + 1 – cos2a = 0 2cos22a = cos2a cos2a = 1 2 2cos2a – 1 = 1 2 ⇒ cos2a = 3 4 Clave E 04 M = 2[2senxcosx](cos2x – sen2x) M = 2sen2xcos2x = sen4x Clave C 05 a + 2q = 90° cosa = sen2q q q a 2q 4 A C M B 2 2 6 6 cosa = 2senqcosq cosa = 2 2 6 2 6 cosa = 2 2 3 Clave D 06 E = – 2cot20° cot20° = –2 Clave B 07 tany 2 = 2x ⇒ 1 – cosy 1 + cosy = 2x 1 – cosy 1 + cosy = 2x ⇒ 1 + cosy 1 – cosy = 1 2x Se pide: 1 + cosy 1 – cosy + 1 + 1 2x = 1 2x + 1 + 1 2x = x + 1 x Clave B 08 E = 2sen2q + 2senqcosq 2cos2q + 2senqcosq E = 2senq(senq + cosq) 2cosq(senq + cosq) E = senq cosq = tanq Clave A 09 P = 2cos2x cos2x + 2sen2x sen2x P = 2 + 2 = 4 Clave A 10 M = 4(2sen20°cos20°)cos40°cos80° sen20° M = 2(2sen40°cos40°)cos80° sen20° M = 2sen80°cos80° sen20° = sen160° sen160° M = 1 Clave A CUADERNO DE TRABAJO 01 Siendo 0 < q < p 8 , 0 < 2q < p 4 sen2q = 26 1 , cos2q = 26 5 Piden: 13sen4q + 5 sen4q 1 5 26 = 26sen2q · cos2q + 5 2sen2q cos2q Pero: sen2q · cos2q = 26 1 · 26 5 = 5 26 26 5 26 + 2 5 26 5 = 5 + 13 = 18 Clave E 02 E = 2sen2x cos2x 2cos22x = sen2x cos2x = tan2x E = 2tanx 1 – tan2x = 2(2) 1 – 22 = –4 3 Clave A 03 • x IV cuadrante senx = 5– 6 , cosx = 6 1 56 1 x • 18cos4x = 18[1 – 2sen22x] Siendo sen2x = 2senx cosx sen2x = 2 5– 6 6 1 = 6 5–2 = – 5 3 18cos4x = 18 10 9 1 – = –2 Clave D 04 tanq = 2 x tan2q = 5 x 3 2 x Sabemos que tan2q = 2tanq 1 – tan2q 5 x = 2 2 1 2 2 x x ( ) − ( ) x = 2 5 tanq = 2 x = 2 52 = 5 1 Clave C 05 Por propiedad: 1 – sen40° = (sen20° – cos20°)2 C = 1 – sen40° + sen20° C = (sen20° – cos20°)2 + sen20° C =|sen20° – cos20°| + sen20° Por C.T. sen20° < cos20° C = cos20° – sen20° + sen20° = cos20° Clave A 06 1 sena – cosa sena = 1 5 csca – cota = 1 5 (1) Sabemos csc2a – cot2a = 1 (csca – cota) 1/5 (csca + cota) = 1 csca + cota = 5 (2) (1) y (2): csca = 13 5 sena = 5 13 , cosa = 12 13 sen2a = 2 5 13 12 13 = 120 169 cos2a = 12 13 5 – 5 13 5 = 119 169 EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 33 26(sen2a – cos2a) = 2 13 Clave B 07 E = tan55° – tan35° = cot35° – tan35° E = 2cot2(35°) = 2cot70° = 2tan20° = 2b Clave E 08 sen15° = 1 x CA 1 M D B 15°15° 120° 30° 30° x x Sabemos: cos2a = 1 – 2sen2a sena = 2 1 – cos2a sen15° = 2 1 – cos30° = 2 32 – 1 x = 2 32 – x = 2 32 + Clave A 09 Área = 1 2 1 2 1 2 + cos2a 1 2 sen2a Área = 1 8 (1 + cos2a)sen2a Área = 1 8 2cos2a 2sena cosa Área = 1 2 cos3a sena 1 2 1 2 1 2 1 2 Clave D 10 Usando cos2A = 1 + cos2A 2 = 1 2 + 1 2 cos2A 1 2 + 1 2 cos p 50 = cos2 p 100 E = 1 2 + 1 2 cos2 p 100 = 1 2 + 1 2 cos p 100 E = cos2 p 200 = cos p 200 Clave C TAREA 01 sen2q = 2senqcosq sen2q = 2 13 2 13 3 = 12 13 q 3 213 02 cos2q = cos2q – sen2q cos2q = 6 7 2 – 1 7 2 = 5 7 03 cotq = 4 ⇒ tanq = 1 4 tan2q = 2tanq 1 – tan2q = 1 – 1 4 2 2 1 4 = 8 15 04 cos2q = cos2q – sen2q 5 x = 5 3 2 – 2 3 2 2 3 x q q 5 x = 9 5 REFORZANDO 01 cos74° = cos2(37°) = 1 – 2sen237° = 1 – 2 3 5 2 = 1 – 18 25 = 7 25 Clave B 02 tan2a = 2tana 1 – tan2a x + 1 3 = 2 1 3 1 – 1 3 2 x + 1 3 = 3 4 ⇒ 4x + 4 = 9 x = 5 4 Clave A 03 • cotx = 5 12 • Construimos la figura con los datos: donde tanx 2 = 12 13 + 5 = 12 18 = 2 3 Clave B 04 Construimos la figura con sena = 3 10 sen2a = 2sena cosa sen2a = 2 3 10 ⋅ 7 10 = 21 5 Clave E 05 Construimos la figura con tan2a = 2 2 De la figura: sena = 2 2 2 6 = 3 3 a 2a 2 2 3 3 1 2 6 Clave D 06 2 tanq + 3tanq cotq = 1 + 2cotq 2 tanq – 2cotq = 1 – 3 cotq – tanq = 3 – 1 2 2cot2q = 3 – 1 2 cot2q = 3 – 1 2 2 Clave C x a a 3 1 13 x/2 x 13 12 5 a 7 3 10 07 • cosβ = – 3 5 • tanβ 2 = – 1 – cosβ 1 + cosβ • tanβ 2 = – 1 + 3 5 1 – 3 5 = –2 • tan2β = 2tanβ 1 – tan2β = 2 4 3 1 – 4 3 2 = – 24 7 3tanβ 2 – 7tan2β = 3(–2) – 7 – 24 7 = 18 Clave C 08 • sena = – 0,2 = – 1 5 • cota 2 = csca + cota cota 2 = –5 – 2 6 cota 2 + 5 = – 2 6 Clave D 09 tan2a = a + bsec2a bcota sec2a bsec2a(cota tan2a– 1) = a bsec2a tan2a tana – 1 = a bsec2a(sec2a) = a cos22a = b a cos4a = 2cos22a – 1 = 2b a – 1 = 2b – a a Clave A 10 Halle el máximo valor de: 2(cos5a sena– sen5a cosa)sen2a cos2a = 2cosa sena (cos4a – sen4a)sen2a cos2a = sen2a (cos2a – sen2a)sen2a cos2a = sen22a cos2a cos2a = sen22a Máx = 1 Clave C 11 K = [(sena–cosa)2]2 + 2sen2a + 1 2 (1–2 sen22a) K = (1 – sen2a)2 + 2sen2a + 1 2 – sen22a K = 1–2sen2a + sen22a + 2sen2a + 1 2 – sen22a K = 1 + 1 2 = 3 2 Clave D 12 3(cos4x + 8cos2x – 8cos4x) = 3[2cos22x – 1 + 8cos2x(1 – cos2x)] = 3[2cos22x – 1 + 8cos2x sen2x)] = 3[2cos22x – 1 + 2(2cosx senx)2] X Y (–3; –4) 5 β X Y (2 6 ; –1) 5a b c ota se c2 a b sec2a b cota b a a a EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 34 = 3[2cos22x – 1 + 2sen22x] = 3[2(cos22x + sen22x) – 1] = 3 Clave E 13 • tana cot a 2 = tana 1 + cosa 1 – cosa = tana 1 + cosa 1 – cosa ⋅ 1 – cosa 1 – cosa = tana sena 1 – cosa = tana sena 1 – cosa ⋅ 1 + cosa 1 + cosa = tana sena(1 + cosa) sen2a = 1 + cosa cosa = seca + 1 ≅ Aseca + B A = 1; B = 1 A2 + B + 1 = 3 Clave E 14 cos x 4 + sen x 4 cos x 4 – sen x 4 2sen x 4 1 – 2sen2 x 8 = cos2 x 4 – sen2 x 4 2sen x 4 cos x 4 = cos x 2 sen x 2 = cot x 2 Clave D 15 (1 + cos2a) + sen2a (1 – cos2a) + sen2a = 12 5 2cos2a + 2sena cosa 2sen2a + 2sena cosa = 12 5 2cosa (cosa + sena) 2sena (sena + cosa) = 12 5 cota = 12 5 En la figura: tan x 2 = 5 25 = 1 5 Clave D ACTIVIDADES CAP 19 IDENTIDADES TRIGONOMÉTRICAS DE ÁNGULO TRIPLE 01 C = 3senx – 4sen3x + senx cos2x C = 4senx(1 – sen2x) (1 – sen2x) = 4senx Clave C 02 L = senx(2cos2x + 1) senx + cosx(2cos2x – 1) cosx L = 2cos2x + 1 + 2cos2x – 1 = 4cos2x Clave C 03 BHT: cos2x = m – n 2n n n xx m m – n B T H A 2x 2x C m – n 2 Clave C 13 13 12 5 a/2 a 04 C = 4 4cos20°cos(60° – 20°)cos(60° + 20°) = 4 cos3(20°) C = 1 2 4 = 8 Clave A 05 K = sen2x(2cos4x + 1) sen2x – cos2x(2cos4x – 1) cos2x K = 2cos4x + 1 – 2cos4x + 1 = 2 Clave B 06 M = 4cos3a 3senacosa sena – sena(2cos2a + 1)cosa sena + 1 M = 3 – 2cos2a – 1 4cos2a + 1 = 1 – cos2a 2cos2a + 1 M = 2sen2a 2cos2a + 1 = tan2a + 1 = sec2a Clave E 07 1 cot2q = 4 ⇒ tan2q = 4 ⇒ tanq = 2 tan3q = 3tanq – tan3q 1 – 3tan2q = 3(2) – (2)3 1 – 3(2)2 ∴ 11tan3q = 2 Clave C 08 E = cos2a cos2a + cos3a cos3a – 8tana 2tana 1 – tan2a E = cos2a cos2a – sen2a cos2a + cosa(2cos2a – 1) cos3a – 4 + 4tan2a E = 1 – tan2a + 4cos2a – 3 cos2a – 4 + 4tan2a E = 1 + 3tan2a – 3sec2a E = 1 – 3(sec2a – tan2a) = 1 – 3 = –2 Clave E 09 K = csc2Asen2A(2cos2A + 1)2 + sec2Acos2A(2cos2A – 1)2 + 2(2cos22A – 1) K = 8cos22A + 2 + 4cos22A – 2 = 12cos22A Clave E 10 sen33°1 2 + cos33° 3 2 = a 2 sen33°sen30° + cos33°cos30° = a 2 cos(33° – 30°) = a 2 ⇒ cos3° = a 2 Se pide: cos9° = cos3(3°) cos9° = 4cos33° – 3cos3° cos9° = 4 a 2 3 – 3 a 2 cos9° = a3 – 3a 2 Clave C CUADERNO DE TRABAJO 01 A = 4cos3x – 3cosx – cosx sen2x = 4cos3x – 4cosx sen2x A = 4cosx(cos2x – 1) sen2x = 4cosx(–sen2x) sen2x A = –4cosx Clave E 02 M = senx(2cos2x + 1) senx – cosx(2cos2x – 1) cosx M = (2cos2x + 1) – (2cos2x – 1) = 2 Clave D 03 Del triángulo: H m = tan3x, H n = tanx mtan3x = ntanx msenx(2cos2x + 1) cosx(2cos2x – 1) = nsenx cosx m n = 2cos2x – 1 2cos2x + 1 n + m n – m = 4cos2x 2 2cos2x = n + m n – m Clave B 04 S = cos20° · cos(60° – 20°) · cos(60° + 20°) S = 1 4 · cos(3(20°)) = 1 4 · cos60° = 1 4 · 1 2 = 1 8 Clave D 05 tanx = tan12° · tan72° · cot42° tanx = tan12° · tan72° · tan48° tanx = tan12° · tan(60° + 12°) · tan(60° – 12°) tanx = tan3(12°) = tan36° x = 36° Clave A 06 E = 1 cos80° + 8cos280° = 1 + 8cos380° cos80° Siendo cos3(80°) = 4cos380° – 3cos80° 4cos380° = cos240° + 3cos80° 4cos380° = – 1 2 + 3cos80° E = cos80° 1 2 1 + 2 + 3cos80°– = 1 – 1 + 6cos80° cos80° E = 6 Clave B 07 J = 3sen(60° + x) – sen(180° + 3x) – sen3x J = 3sen(60° + x) + sen3x – sen3x J = 3sen(60° + x) Clave D 08 4J = 4cos3x + 4cos3(120° – x) + 4cos3(120° + x) 4J = 3cosx + cos3x + 3cos(120° – x) + cos3x + 3cos(120° + x) + cos3x EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 35 4J = 3cosx + 3cos3x + 3[cos(120° – x) + cos(120° + x)] 4J = 3cosx + 3cos3x + 3[2cos120°cosx] 4J = 3cosx + 3cos3x + 3 · 2 1 2 – cosx J = 3 4 cos3x Clave E 09 tan20° + tan40° + tan220° tan240° cot10° tan20° + tan40° + tan220° tan240° tan80° Por propiedad: tan20° tan40° tan80° = tan60° tan20° + tan40° + 3tan20° tan40° tan(20° + 40°) = 3 Clave B 10 DHC: tan2x = 11 5 NHC: cotx = 11 1 Luego: tan2x · cotx = 11 5 2 2 2 2 1 H B N C2k 2x 2k k x x x xx 2x 6 D A E 11 Clave A TAREA 01 Dato: sena = 1 5 , piden sen3a sen3a = Sen 3a – 4sen3a sen3a = 3 1 5 – 4 1 5 3 = 3 5 – 4 125 = 71 125 02 cosq = 1 3 , piden: cos3q cos3q = 4 cos3q – 3cosq cos3q = 4 1 3 3 – 3 1 3 = 4 27 – 1 = – 23 27 03 Tan = 3q = 3tanq – tan3q 1 – 3tan2q = 3(2) – 23 1 – 3(2)2 tan3q = 2 11 04 M = cos3x cosx +1 m = cosx(2cos2x – 1) cosx + 1 M = 2cos2x – 1 + 1 = 2cos2x REFORZANDO 01 senx = 0,5 senx = 1 2 sen3x = 3senx – 4sen3x sen3x = 3 1 2 – 4 1 2 3 = 1 Clave E 02 Se sabe que: sen3x = 3senx – 4sen3x sen3x + 4sen3x = 3senx sen3x + 4sen3x 3 = senx Clave A 03 Se sabe: I. sen3x = senx(2cos2x + 1) sen3x senx = 2cos2x + 1 II. cos3x = cosx(2cos2x – 1) cos3x cosx = 2cos2x – 1 Reemplazando en la expresión: (2cos2x + 1) + (2cos2x – 1) – 4cos2x = 0 Clave D 04 Se sabe: tan3x = tanx 2cos2x + 1 2cos2x – 1 tan3x tanx = 1 5 2 + 1 1 5 2 – 1 = – 7 3 Clave E 05 tanx = 11 tan3x = 3tanx – tan3x 1 – 3tan2x = 3(11) – (11)3 1 – 3(11)2 tan3x = 1298 362 = 3,58 Clave C 06 csc3x = 5 3 sen3x = 3 5 sen3x = sen(2x + x) = sen2xcosx + senxcos2x = 2senxcosxcosx + senxcos2x = senx(2cos2x + cos2x) = senx(1 + cos2x + cos2x) = senx + 2senxcos2x = 3 5 Clave A 07 cotx = 2 2 , construimos la figura: cos3x = 4cos3x – 3cosx cos3x = 4 2 2 3 3 – 3 2 2 3 cos3x = 10 2 27 Clave D 13 x 22 08 tan2a = 2tana 1 – tan2a x + 1 3 = 1 3 1 3 2 1 – 2 x = 5 4 tan3a = 3tana – tan3a 1 – 3tan2a 1 + x + y 3 = 1 3 1 27 1 9 3 – 1 – 3 . 1 + x + y 3 = 13 9 1 + 5 4 + y = 13 3 y = 25 12 Clave C 09 Se sabe que: cos3x = cosx(2cos2x – 1) cos3x = 6 2 15 (2 . 1 5 – 1) cos3x = 3 15 . –3 5 = – 3 15 25 Clave B 10 4cos3x – 3cosx cosx = m 4cos2x – 3 = m 2(1 + cos2x) = m + 3 cos2x = m + 1 2 Clave C 11 3senx – 4sen3x senx + 4cos3x – 3cosx cosx = 3 – 4sen2x + 4cos2x – 3 = –4(1 – cos2x) + 4cos2x = –4 + 8cos2x = – 4 + 4(1 + cos2x) = 4cos2x ≡ 2kcoskx k = 2 Clave C 12 cos3a – (4cos3a – 3cosa) cosa + sen3a + (3sena – 4sen3a) sena = – 3cos2a + 3 + 3 – 3sen2a = – 3(cos2a + sen2a) + 6 = 3 Clave C 13 sen2x = cos3x 2senxcosx = 4cos3x – 3cosx 2senx = 4(1 – sen2x) – 3 4sen2x + 2senx – 1 = 0 senx = –2 ± 4 – 4(4)(–1) 2(4) , x∈〈0; p 2 〉 senx = 5 – 1 4 Clave A 1 x y 3 15 5 x x 2x 62152 EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 36 14 tan2φ = 2tanφ 1 – tan2φ 7 y = 3 y 3 y 2 1 – 2 y = 3 7 tan3φ = 3tanφ – tan3φ 1 – 3tan2φ x + 7 3 7 = 3 3 7 3 3 7 3 3 7 3 3 2 – 1 – 3 x + 7 3 = 5 x = 8 Clave E 15 BH = sen2x = 2cos3x 2senxcosx = 2(4cos3x – 3cosx) senx = 4(1 – sen2x) – 3 4sen2x + senx – 1 = 0 senx = –1 ± 12 – 4(4)(–1) 2(4) senx = 17 – 1 8 Clave A ACTIVIDADES CAP 20 TRANSFORMACIONES TRIGONOMÉTRICAS I 01 E = 2sen60°cos10° cos10° = 2 3 2 = 3 Clave B 02 M = 2sen6xcos2x + 2 3cos2x cos2x M = 2sen6x + 2 3; 9x – 4(180°) = 0 ⇒ x = 80° M = 2sen(+480°) + 2 3 M = +2sen120° + 2 3 = +2 3 2 + 2 3 M = 3 3 Clave D 03 R = 1 + cos4a + 2sen4acos2a (1 + 2sen2a)(1 + cos4a) R = 2cos22a + 2(2sen2acos2a)cos2a (1 + 2sen2a)(2cos22a) R = 2cos22a(1 + 2sen2a) (1 + 2sen2a)2cos2a = 1 Clave A 04 3cosa = sen70° – sen10° –(–cos20°) 3cosa = 2sen30°cos40° + cos20° 3cosa = 2 1 2 cos40° + cos20° 3cosa = 2cos30°cos10° 3 4 x y φ φφ 1 2 A H C B 2x 3x 3cosa = 2 3 2 cos10° a = 10° Clave C 05 2E = 2sen30°cos10° – cos10° 2E = 2 1 2 cos10° – cos10° E = 0 Clave D 06 2M sen4° cos8° = 2sen8°cos1° + 2sen8°cos8° 2cos8°cos1° + cos2(8°) + 1 2M sen4° cos8° = 2sen8°(cos1° + cos8°) 2cos8°cos1° + 2cos28° 2M sen4° = sen8°(cos1° + cos8°) (cos1° + cos8°) 2M sen4° = 2sen4°cos4° M = cos4° Clave E 07 ksen40°cos40°cos100° = cos100° + cos40° – k 2 sen80°cos80° = 2cos70°cos30° – k 4 sen160° = 2sen20° 3 2 – ksen20° = 4 3sen20° k = –4 3 Clave E 08 Propiedad: F = 4senAsenBsenC senAsenBsenC = 4 Clave D 09 E = sen40° + cos70° cos10° = sen40° + sen20° cos10° tana = 2sen30°cos10° cos10° = 2 1 2 = 1 tana = tan45° ⇒ a = 45° = p 4 Ca = 45° = p 4 Clave E 10 x = –1 ; y = –2 r = 5 E = 2sen3acos2a X Y O (–1; –2) (–2; 1) a 5 E = 2(3sena – 4sen3a)(1 – 2sen2a) E = 2 3 –2 5 – 4 –2 5 3 1 – 2 –2 5 2 25 5E = –12 Clave C CUADERNO DE TRABAJO 01 Por transformación de suma a producto: 2sen2x cosx –2sen2x senx = –cotx Clave C 02 Transformando de suma a producto: 2sen3x · cos2x 2cos3x · cos2x = 3 tan3x = 3 3x = 60° x = 20° Clave B 03 Usando 0,5 como sen30°. sen30° + 2sen20° + sen10° = Asen20°cos25° 2sen20°cos10° + 2sen20° = Asen20°cos25° 2sen20°(1 + cos10°) 2cos25° = Asen20°cos25° 4sen20°cos25° = Asen20°cos25° A = 4 Clave A 04 2csc18° + 4sen6°csc18° 4csc18° 1 2 + sen6° 4csc18°(sen30° + sen6°) 4csc18°(2sen18°cos12°) 8csc18°sen18° 1 cos12° 8cos12° Clave B 05 ksen82° = sen8° + 2cos38° ksen82° = sen8° + cos38° + cos38° ksen82° = sen8° + sen52° + cos38° ksen82° = 2sen30° 1/2 cos22° + cos38° ksen82° = cos22° + cos38° kcos8° = 2cos30°cos8° k = 2 3 2 = 3 Clave C 06 E = sen2130° – sen210° 2E = 2sen2130° – 2sen210° 2E = (1 – cos260°) – (1 – cos20°) 2E = cos20° – cos260° = 2sen140° sen120° E = sen40° sen60° = 3 2 sen40° = 2csc40° 3 Piden: 2Ecsc40° = 3 Clave C 07 Factorizando 8sen3a: 8sen3a (2sen4a – 3sen2a + 1) 8sen3a (2sen2a – 1)(sen2a – 1) 8sen3a (1 – 2sen2a)(1 – sen2a) 8sen3a · cos2a · cos2a 2sena · cos2a (4sen2a · cos2a) sen22a sena · sen2a (2sen2a · cos2a) sena · sen2a · sen4a Clave E 08 Llevando senos y cosenos EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 37 = = senA senB cosA cosB A B A B A B A B + + = +( ) −( ) +( ) −( ) 2 2 2 2 2 2 sen cos cos cos = tan A + B 2 = tan60° = 3 Clave D 09 cos(2a + b) – cos(2b + a) = m –2sen 3 2 (a + b) sen a – b 2 = m –2sen 3 2 5p 3 sen a – b 2 = m – 2 m = csc a – b 2 – 2 m = –csc b – a 2 csc b – a 2 = 2 m Clave D 10 2sen5a – sen3a = 0 sen5a + sen5a – sen3a = 0 sen(4a + a) + 2cos4a sena = 0 sen4a cosa + cos4a sena + 2cos4a sena = 0 Dividiendo entre cos4a cosa: tan4a + tana + 2tana = 0 tan4a = –3tana Piden: a = tan4a – 2 + 3tana 0 = –2 aa = (–2)–2 = 1 4 Clave C TAREA 01 J = 2sen4xcos3x cos3x J = 2sen4x 02 H = 2cos2xcosx sen2x = 2cot2xcosx 03 M = 2sen16°cos64° sen26° = 2sen16°sen26° sen26° M = 2sen16° 04 P = 2sen45°sen25° sen25° P = 2 2 2 = 2 REFORZANDO 01 2sen 5x + 3x 2 cos 5x – 3x 2 sen4xcosx = 2sen4xcosx sen4xcosx = 2 Clave B 02 2cos 3x + x 2 cos 3x – x 2 2cosxcos2x = 2cos2xcosx 2cosxcos2x = 1 Clave A 03 cos165° + cos105° = cos 165° + 105° 2 cos 165° – 105° 2 = cos135°cos30° = – 2 2 . 3 2 = – 6 4 Clave E 04 sen7x + senx sen4x = 2sen4xcos3x sen4x = 2cos3x Clave D 05 (sen20° + cos20°)sec25° = (cos70° + cos20°) 1 cos25° = 2cos45°cos25° cos25° = 2cos45° = 2 2 2 = 2 Clave B 06 (cos3a+ cosa) + cos2a (sen3a + sena) + sen2x = 2cos2acosa + cos2a 2sen2acosa + sen2a = cos2a (2cosa + 1) sen2a (2cosa + 1) = cos2a sen2a = cot2a Clave C 07 (cos40° + cos40° + cos80°)csc80° = (cos40° + 2cos60°cos20°)csc80° = (cos40° + cos20°)csc80° = 2cos30°cos10°csc80° = 2 3 2 . sen80°csc80° = 3 Clave C 08 M = 2cos60°senx = senx N = 2cos30°senx = 3 senx MN = senx( 3 senx) = 3 sen2x Clave A 09 M = sen10° + sen70° + sen50° sen70° + sen10° – sen50° M = 2sen 30°cos20° + sen70° 2cos60°sen10° + sen10° M = 2sen70° 2sen10° = cos 20° sen 10° Msen10° = cos20° Clave B 10 [6csc10°cos65° – 3 2csc10°] sen35° = [6csc10°(cos65° – 2 2 )] sen35° = [6csc10°(cos65° – cos45°)] sen35° = [6csc10°(–2sen55°sen10°)] sen35° = –6csc10°sen10° (2cos35°sen35°) = –6sen70° = –6cos20° Clave D 11 1 2 + sen10° 2cos10° 2 sen40° + sen30° = 2(sen30° + sen10°)sen40° 2cos10° + sen30° = 2(2sen20°cos10°)sen40° 2cos10° + sen30° = 2sen40°sen20° + sen30° = cos20° – cos60° + sen30° = cos20° Clave C 12 • cos220° – 1 4 = cos220° – sen230° = 2cos220° - 2sen230° 2 = (1 + cos40°) – (1 – cos60°) 2 = cos40° + cos60° 2 = 2cos50°cos10° 2 = cos50° . cos10° A = 50° , B= 10° • 4 3 sen(A + B) = 4 3 sen60° = 4 3 3 2 = 6 Clave B 13 Tenemos : 4csc25° . sen5°(2sen25°.cos10° + sen25°) = 4csc25° . sen5° . sen25°(2cos10° + 1) = 4csc25° . sen5° . sen25° sen15° sen5° = 4sen15° = 4 6 - 2 4 = 6 - 2 Clave C 14 cos42x – cos44x (cos6x.cos2x + 1)sen6x.sen2x = (cos22x + cos24x)(cos2x + cos4x)(cos2x – cos4x) (cos6x.cos2x + 1)sen6x.sen2x EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 38 = (cos6xcos2x + 1)(2sen3xcos3x)(2senxcosx) 1 + cos4x 2 1 + cos8x 2 + (2cos3xcosx)[–2sen3xsenx] = 1 2 (cos4x + cos8x + 2) cos6x.cos2x + 1 = 1 2 (2cos6x.cos2x + 2) cos6x.cos2x + 1 = 1 Clave A 15 sen2a + sen2β + sen2ω = 2sen(a + β)cos(a – β) + sen2ω = 2senω . cos(a – β) + 2senω . cosω– = 2senω[cos(a - β) + cosω] = 2senω2cos a – β + ω 2 cos a – β – ω 2 = 4 senω . senβ . sena ∴ Si E es el número buscado, E = 4sena.senβ.senω –10senω.senβ.sena = – 2 5 Clave C ACTIVIDADES CAP 21 TRANSFORMACIONES TRIGONOMÉTRICAS II 01 M = sen70° + sen20° – cos20° + cos90° M = sen70° + sen20° – sen70° + 0 M = sen20° Clave E 02 Ysen10° = sen70° – 2cos80°cos20° – 2cos80°cos40° – (1)cos80° Ysen10° = sen70° – cos100° – cos60° – cos120° – cos40° – cos80° Ysen10° = sen70° – sen50° = 2sen10°cos60° Y = 2 1 2 = 1 Clave E 03 P = 3cos10° – 6sen20°sen10° P = 3cos10° – 3(cos10° – cos30°) P = cos30° = 3 2 3 Clave A 04 2Y = sen120° + sen20° + sen540° – sen20° 2Y = sen60° + 0 ⇒ 2Y = 3 2 Y = 3 4 Clave C 05 2M = 1 + 2(cos10° – cos60°) M = cos10° 3M – 4M3 = 3cos10° – 4sen310° = – cos30° 3M – 4M3 = – 3 2 Clave D 06 M = sen7x – senx – sen7x + sen3x cos11x + cos3x – cos11x – cosx M = sen3x – senx cos3x – cosx Pero: x = p 24 ⇒ 12x = p 2 M = cos9x – cos11x sen9x – sen11x = – 2sen10xsenx 2cos10xsenx M = –tan10x = – tan10 p 24 = – tan75° M = – 6 + 2 6 – 2 = –(2 + 3) Clave D 07 2H = cosx 2 2 + senx 2 2 + 2 2 sen3x – 2 2 senx cosx – cos 3x + p 2 2H = 2 2 (cosx + sen3x) cosx + sen3x = 2 2 1 = 2 H = 2 2 Clave A 08 Evalunado para: x = p6 = 30° 16(sen30°)5 = Asen30° + Bsen90° + Csen150° 16 1 2 5 = A 1 2 + B(1) + C 1 2 A + 2B + C = 1 Clave C 09 L = sen6q – sen3q + sen4q + sen3q 2sen2qsen5q L = sen6q + sen4q 2sen2qsen5q = 2sen5qcosq 2sen2qsen5q L = cosq 2senqcosq = cscq 2 Clave D 10 dato: a + γ = 153°30' mBB = 26°30' = 53° 2 a γ 26°30' S A c = cos26° B C a = sen27° sen1° = 7 400 S = 1 2 sen27°cos26°sen53° 2 S = 1 4 (sen53° + sen1°) 1 5 S = 5 20 4 5 + 7 400 = 327 5 8000 Clave E CUADERNO DE TRABAJO 01 E = 2cos80° + 4sen70°sen10° E = 2cos80° + 2[cos60° – cos80°] E = 2cos60° = 2 1 2 = 1 Clave A 02 Multiplicamos por 2 para generar la transformación: 2E = 2senx sen3x + 2senx sen5x + 2senx sen7x + 2senx sen9x 2E = cos2x – cos4x + cos4x – cos6x + cos6x – cos8x + cos8x – cos10x 2E = cos2x – cos10x = 2sen6x sen4x E = sen6x sen4x Clave B 03 Factorizando: = 2sen20° 3 2 + sen20° 2sen70° + cos60° = 2sen20°(sen60° + sen20°) 2sen70° + cos60° = 2sen20° 2sen40° cos20° 2sen70° + cos60° = 2sen20° sen40° + cos60° = cos20° – sen60° + cos60° = cos20° Clave B 04 M = sen12° cos18° + sen18° cos12° sen30° + cos48°cos12° M = 1 2 + cos48°cos12° = 1 + 2cos48°cos12° 2 M = 1 + cos60° + cos36° 2 M = 1 + 1/2 + cos36° 2 cos36° = 4M – 3 2 Clave C 05 Sea M = csc10° – 4cos20°= 1 sen10° – 4cos20° M = 1 – 4sen10°cos20° sen10° M = 1 – 2(sen30° – sen10°) sen10° M = 1 – 2sen30° + 2sen10° sen10° = 2 Clave E 06 (sen6x – sen4x) + sen4x (cos3x + cosx) – cosx = 2sen3x cos3x cos3x 2sen3x Clave D 07 R = cos60° – 2cos(15° + x) sen(15° – x) + sen4x cos4x + cos2x R = cos60° – (sen30° – sen2x) + sen4x 2cos3x cosx EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 39 R = sen2x + sen4x 2cos3x cosx = 2sen3x cosx 2cos3x cosx tan3x Clave C 08 senx 1 + cos2x 2 = asenx + bsen3x senx 2 + senx cos2x 2 = asenx + bsen3x 2senx 4 + 2senx cos2x 4 = asenx + bsen3x 2senx + sen3x – senx 4 = asenx + bsen3x senx + sen3x 4 = asenx + bsen3x 1 4 senx + 1 4 sen3x = asenx + bsen3x a + b = 1 4 + 1 4 = 1 2 Clave A 09 2cos2a cosa + cosa – cos3a 2sen3a cosa cos3a + cosa + cosa – cos3a 2sen3a cosa = 2cosa 2sen3a cosa csc3a Clave B 10 • 2sen210° = 1 – a 1 – cos20° = 1 – a a = cos20° • Piden: 1 + 2(2cos40° sen10°) 2 1 + 2(sen50° – sen30°) 2 sen50° = cos40° = 2cos220° – 1 = 2a2 – 1 Clave C TAREA 01 A = cos30° + cos10° – cos10° A = 3 2 02 E = sen50° + sen30° – cos40° E = cos40° + 1 2 – cos40° E = 1 2 03 E = sen70° + sen30° – sen90° – sen70° E = 1 2 – 1 = – 1 2 04 P = cos6x – cos8x + cos8x P = cos6x REFORZANDO 01 2 2 sen45°cos15° = 1 2 (sen60° + sen30°) = 1 2 3 2 – 1 2 = 3 – 1 4 Clave B 02 2sen41°cos12° – sen29° = sen(41° + 12°) + sen(41° – 12°) – cos29° = sen53° + sen29° – sen29° = 4 5 Clave D 03 2 2 2 cos8° = 2cos45°cos8° = cos53° + cos37° = 3 5 + 4 5 = 7 5 Clave E 04 2 3 2 sen7° + sen23° = 2cos30°sen7° + sen23° = sen37° – sen23° + sen23° = 3 5 Clave C 05 M = sen60° + sen20° – sen20° cos45° + cos25° – cos25° M = sen60° sen45° = 3 2 2 2 = 3 2 = 6 2 Clave B 06 2(2senxcos2x)sen3x + 2sen3xsenx 2(sen3x – senx) sen3x + 2sen3xsenx = 2sen23x – 2senxsen3x + 2sen3xsenx = 2sen23 p 6 = 2sen2 p 2 = 2 Clave A 07 M = 2cos40°cos20° + 2sen50°cos80° –2(2sen60°cos10°) M = cos60° + cos20° + sen130° – sen30° –2(sen70° + sen50°) M = sen70° + sen50° –2(sen70° + sen50°) = – 1 2 Clave D 08 1 2 (2sen6xsen2x) + cos24x = 1 2 (cos4x – cos8x) + 1 2 (1 + cos8x) = 1 2 (1 + cos4x) = 1 2 (2cos22x) = cos22x Clave B 09 2M = cos(a+β) + cos(a–β) + cos(β+γ) + cos(β–γ) + cos(γ+a) + cos(γ–a) – [cos(a–β) + cos(β–γ) + cos(γ-a) - 1] 2M = –cosγ – cosa – cosβ + 1 2M = –2cos γ + a 2 cos γ – a 2 + 2sen2 β 2 2M = –2sen β 2 cos γ – a 2 + 2sen2 β 2 2M = 2sen β 2 sen β 2 – cos γ – a 2 = 2sen β 2 cos γ + a 2 – cos γ – a 2 2M = 2sen β 2 –2sen γ 2 sena 2 M = –2sena 2 sen β 2 sen γ 2 Clave C 10 E = 1 4 + + 2cos55°sen45° 2 2sen80°sen20° 2 = 1 4 + – + – sen100° 2 cos100° 2 sen10° 2 cos60° 2 = 1 2 + – –cos10° 2 sen10° 2 –sen10° 2 = 1 +cos10° 2 = 2cos25° 2 = cos5° Clave C 11 4cos20° – 3 cot20° = 4cos20° – 3 cos20° sen20° = 2sen40° – 3 cos20° sen20° = 2(2sen30°sen40° – cos30°cos20°) sen20° = 2(cos10° – cos70°) – (cos50° + cos10°) sen20° = cos10° – cos50° – 2cos70° sen20° = 2sen30°sen20° – 2sen20° sen20° = –sen20° sen20° = –1 Clave B 12 tg x 2 . tg 5x 2 = a 2sen 2cos sen cos 5x 2 5x 2 x 2 x 2 = a cos2x – cos3x cos3x + cos2x = a EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 40 cos2x(1 – a) = cos3x(a + 1) cos2x cos3x = a+ 1 1 – a Clave D 13 Multiplicando por senx el 1° miembro: senx + 4cos3xcosxsenx senx = sen(Ax) sen(Bx) senx + 2(2senxcosx)cos3x senx = sen(Ax) sen(Bx) senx + 2sen2xcos3x senx = sen(Ax) sen(Bx) senx + (sen5x – senx) senx = sen(Ax) sen(Bx) sen5x senx = sen(Ax) sen(Bx) A = 5 ∧ B = 1 AB + A – B = 9 Clave C 14 M = cos2p 7 + cos4p 7 + cos6p 7 2sen3p 7 M = 2sen3p 7 cos2p 7 + 2sen3p 7 cos4p 7 + 2sen3p 7 cos6p 7 = sen5p 7 + sen p 7 + sen7p 7 – sen p 7 + sen9p 7 – sen3p 7 = sen2p 7 + 0 – sen2p 7 – sen3p 7 M = – 1 2 Clave B 15 Multiplicando por 2 y transformando: 2E = cos2p 7 – cos6p 7 + cos2p 7 – cos10p 7 – 3cos2p 7 2E = –cos6p 7 – cos10p 7 – cos2p 7 Pero: cos10p 7 = cos4p 7 2E = –(cos2p 7 + cos4p 7 + cos6p 7 ) 2E = –(– 1 2 ) E = 1 4 Clave D ACTIVIDADES CAP 22 FUNCIONES TRIGON.: SENO Y COSENO 01 –2cosx – 1 ≥ 0 ⇒ cosx ≤ – 1 2 x ∈ 2p 3 ; 4p 3 prob. 14 –cosx ≥ 0 ⇒ cosx ≤ 0 x ∈ p 2 ; 3p 2 dom(f) = 2p 3 ; 4p 3 Clave D 02 –1 ≤ senx ≤ 1 – p 4 ≤ p 4 senx ≤ p 4 – 2 2 ≤ cos p 4 senx ≤ 2 2 – 2 ≤ –2cos p 4 senx ≤ 2 1 – 2 ≤ 1 – 2cos p 4 senx ≤ 1 + 2 a = 1 – 2 ; b = 1 + 2 a + b = 2 Clave D 03 f(x) = senx – 2 2 – senx + 1 = 1 3 – senx – 1 –1 ≤ senx ≤ 1 2 ≤ 3 – senx ≤ 4 1 4 ≤ 1 3 – senx – 1 ≤ 1 2 – 3 4 ≤ f(x) ≤ – 1 2 Clave A 04 1 + sen 2px – p 2 = 1 sen 2px – p 2 = 0 2px – p 2 = 0 ⇒ x = 1 4 2px – p 2 = p ⇒ x = 3 4 Por lo tanto, el número de valores de x en el intervalo [0 ; 1] es 2. Clave E 05 x ∈ p 2 ; p ; f(x) = (senx + 3)2 – 5 0 < senx ≤ 1 3 < senx + 3 ≤ 4 9 < (senx + 3)2 ≤ 16 4 < (senx + 3)2 – 5 ≤ 11 ∴fmín = 5 Clave C 06 sen(nx)cos(2mx) + sen(2mx)cos(nx) = sen(nx + 2mx) = sen(n + 2m)x Clave B 07 f(x) = [(cos2x + sen2x)(cos2x – sen2x)] = |cos2x| Periodo: T = p 2 p 4 p 2 3p 4 p 1 Y X0 T T Clave D 08 f(x) = –2sen3x Clave E 09 p 4 p 2 p 2 Y cosx X S 2 2 2 2 p 4 –p 2 – p 4 ; 2 2 ⇒ S = p 2 2 2 ∴ S = p 2 4 u2 Clave E 10 f(x) = sen2x – 1 + sen2x sen2x – 1 ≥ 0 ⇒ sen2x ≥ 1 ⇒ sen2x = 1 senx = ± 1 ⇒ x = (2n – 1) p 2 ; n ∈ p 2 p 2 3p 2 Y X0– Clave C CUADERNO DE TRABAJO 01 Ran(f) = [–1; 1] Clave A 02 T = 3p 4 – p 4 – = p Y X Clave A 03 I. (F) f(x) = cos2x y f(x) = 2cosx tienen el mismo dominio . II. (F) El rango de f(x) = cos2x es [–1; 1] y el de f(x) = 2cosx, [–2; 2]. III. (V) El dominio de ambos es . Clave B 04 El gráfico corresponde a la función: f(x) = 5sen3x Clave E 05 EDITORIALINGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 41 Respecto al gráfico: I. (F) El dominio de f(x) es [–p/6; 3p/2 II. (F) El rango de f(x) es [–5; 5] III. (V) El periodo T = 2p 3 – 0 = 2p 3 Clave C 06 Según el gráfico es correcto: I. (F) Si a = 2 n = p 4 II. (F) Si a = 3 n = p 6 III. (V) Si a = 1 2 n = p Clave C 07 Ran(f) = 1 2 3 2 ; 1 2 3 2 Clave C 08 f(x) = 3secx + 4 = 3 cosx + 4 Como –1 cosx 1 – < 1 cosx –1 1 1 cosx < – < 3 cosx + 4 1 7 3 cosx + 4 < f(x) –; 1] [7; + No pertenecen: 2; 3; 4; 5; 6 Piden: 2 + 3 + 4 + 5 + 6 = 20 Clave E 09 Como x p ; 5p 4 |senx|= –senx f(x) = 1 + 2(–senx)cosx = (senx – cosx)2 f(x) =|senx – cosx|= senx – cosx f(x) = 2sen p 4 x – Siendo p < x < 5p 4 3p 4 < x – p 4 < p 0 < sen p 4 x – < 2 2 0 < 2sen p 4 x – < 1 0 < f(x) < 1 Clave B 10 A Y XB C x y y1 x1 x1 = p 4 x2 = 5p 4 y1 = 2 2 y2 = 2 2– A p 4 ; 2 2 B(p; 0) C ;5p 4 2 2– A = 8 2p (Por determinantes) Clave D TAREA 01 Ran(f) = [–1; 1] 1 –1 Ran(f) = [–1; 1] 02 –1 1 y = sen3x 2 03 f(x) = sen(x + p/5): x ∈ ⇒ x + p/5 ∈ 〈–∞;∞〉 ⇒ Domf = R ⇒ Domg = ∴ Domf = Domg = 04 senxcosx ≠ 0 ⇒ 2senxcosx ≠ 0 ⇒ sen2x ≠ 0 senx = 0 ⇔ x = 0; p, 2p; ...; np; n ∈ ⇒ sen2x ≠ 0 ⇔ 2x ≠ np ⇒ x ≠ np 2 ∴ Domf = – {np 2 /n∈} REFORZANDO 01 –3 O 3 f(x) = 3sen2x Ran(f) Ran(f ) = [–3;3] Clave A 02 – y = f(x) O –3 3 y = 3senx T = 3p 8 – (– p 8 ) = p 2 Clave B 03 I. (V) II. (F) III. (F) Clave A 04 De la ecuación: y = cos(2x – p) = cos(p –2x) y = cos2x ⇒ t = p Clave C 05 – – y = f(x) –3 3 Respecto al gráfico: I. (V) Donf(x) es 〈–3p/5; 3p/5〉 II. (V) Ranf(x) es [–3; 3] III. (F) T = 3/5 Clave D 06 Sea 2(x + p 5 ) = q En f(x) = Asenq, el rango depende solamente de A y no de q. Clave E 07 I. (F) Elrango de f(x) = 2cos2x es [–2;2] II. (F) El dominio de f(x) = cos2x es . III. (V) El rango depende de A. Clave B 08 El gráfico corresponde a la función f(x) = 2cos2x Clave C 09 El dominio es tal que T = p f(x) = cos2x T = f(x) = cos3x T = f(x) = cosx/2 f(x) = –4cosq Ran(f) Ran(f) = [–4;4] y = senx –4 4 EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 42 sen x 2 ≠ 0 ∧ cos x 2 ≠ 0 ⇒ x 2 ≠ np/n ∈ ∧ x 2 ≠ (2n+1) p 2 / n ∈ ⇒ x ≠ 2np/n ∈ ∧ x ≠ (2n+1)p/ n ∈ ⇒ x ≠ 2kp/k ∈ ∴ x ∈ – {kp/k ∈ } Clave A 10 Dado que f(x) = 1 – senx – cos2x = sen2x – senx f(x) = sen2x – senx + 1 4 – 1 4 f(x) = (senx – 1 2 )2 – 1 4 Como: – 1 ≤ senx ≤ 1 – 3 2 ≤ senx – 1 2 ≤ 1 2 0 ≤ (senx – 1 2 )2 ≤ 9 4 – 1 4 ≤ (senx – 1 2 )2 – 1 4 ≤ 8 4 ∴ – 1 4 ≤ f(x) ≤ 2 Clave C 11 Dando la forma a f(x) f(x) = senx – 2 + 3 senx – 2 = 1 + 3 senx - 2 Siendo: – 1 ≤ senx ≤ 1 – 3 ≤ senx – 2 ≤ –1 – 1 ≤ 1 senx – 2 ≤ – 1 3 – 3 ≤ 3 senx – 2 ≤ – 1 – 2 ≤ 1 + 3 senx – 2 ≤ 0 ∴ –2 ≤ f(x) ≤ 0 Clave E 12 Si L = asenx + bcosx Lmáx = a2 + b2 Lmín. = – a2 + b2 Para f(x) = 3senx + 2cosx Ranf = [– 32 + 22 ; + 32 + 22 ] Ranf = [– 13; 13] Clave B 13 – 1 ≤ sen(2px – p 2 ) ≤ 1 0 ≤ 1 + sen(2px – p 2 ) ≤ 2 0 ≤ f(x) ≤ 2 Clave C 14 g(x) = sen3x f(x) = cos3x Del dato: Sen23x + 2cos23x = 1 1 +cos23x = 1 cos23x = 0 cos3x = 0 3x = p 2 ; 3p 2 ; 5p 2 ; 7p 2 x = p 6 ; p 2 ; 5p 6 ; 7p 6 ∴ p 6 + p 2 + 5p 6 = 3p 2 Clave E 15 Siendo –1 ≤ senx ≤ 1 ⇒ –3 ≤ senx – 2 ≤ –1 ⇒ |senx – 2 | (–) = 2 – senx Piden: f(x) = senx – 2 2 – senx + 1 = senx – 2 3 – senx = 1 3 – senx – 1 Sabemos que: –1 ≤ senx ≤ 1 –1 ≤ –senx ≤ 1 2 ≤ 3 – senx ≤ 4 1 4 ≤ 1 3 – senx ≤ 1 2 – 3 4 ≤ 1 3 – senx – 1 ≤ – 1 2 ∴ – 3 4 ≤ f(x) ≤ – 1 2 Clave D ACTIVIDADES CAP 23 FUNCIONES TRIGON.: TANGENTE 01 f(x) = 1 tan2xtanx tanx ≠ 0 ⇒ x ∉ [... ; –p ; 0 ; p ; 2p ; ...] tan2x ≠ 0 ⇒ 2x ∉ [... ; –p ; 0 ; p ; 2p ; ...] ∴ Domf = – { kp 4 /k ∈ } Clave B 02 f(x) = 3 – tanx + tanx – 1 3 – tanx ≥ 0 ⇒ tanx ≤ 3 tanx – 1 ≥ 0 ⇒ tanx ≥ 1 ∴ Ranf = [1 ; 3] Clave C 03 f(x) = 1 tanx + 1 senx = cosx senx + 1 senx f(x) = 1 + cosx senx senx ≠ 0 ⇒ x ∉ {... ; –p ; 0 ; p ; 2p ; ...} ∴ Domf = – {kp/k ∈ } Clave A 04 f(x) = tan2x – 1 – tan2x 2tanx f(x) = 2tan3x + tan2x – 1 2tanx tanx ≠ 0 ⇒ x ∉ {... ; –p ; 0 ; p ; 2p ; ...} ∴ x ∈ – {kp/k ∈ } Clave A 05 f(x) = 3tanx ; x ∈ 2p 3 ; 7p 6 f 2p 3 = 3(– 3) = –3 f 7p 6 = 3 3 3 = 1 ∴ (–3)(1) = – 3 Clave C 06 p 4 ≤ x ≤ p 3 ⇒ 1 ≤ tanx ≤ 3 0 ≤ tanx – 1 ≤ 3 – 1 1 – 3 ≤ 1 – tanx ≤ 0 f(x) = tanx – 1 + –(1 – tanx) = 2tanx – 2 1 ≤ tanx ≤ 3 ⇒ 2 ≤ 2tanx ≤ 2 3 0 ≤ 2tanx – 2 ≤ 2 3 – 2 ∴ Ranf = [0 ; 2 3 – 2] Clave D 07 Área: S = p(2 3) ∴ S = 2p 3 Clave D 08 Área: S = p(1) ∴ S = pu2 Clave D 09 f(x) = 2senxcosxsenx 2senxcosx = senx f(x) = senx ; x ∈ [0 ; 2p] Clave B 10 f(x) = senx ; g(x) = tanaa ; x ∈ [0 ; 4p] p 4 1 2 3 4 5 6 7 8 9 p 2p 3p 4p Por lo tanto hay 9 puntos de intersección. Clave B CUADERNO DE TRABAJO 01 i) tanx x (2k + 1)p 2 (1) ii) tan2x 2x (2k + 1)p 2 x (2k + 1)p 4 (2) iii) tan2x 2x kp x kp 2 (3) De (1), (2) y (3): x kp 4 Dom f(x) – kp 4 / k Clave C EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 43 02 Dom f(x) – kp 6 Y X 3x (2k + 1)p 2 x (2k + 1)p 6 3x kp x kp 3 Clave A 03 El dominio de f(x) es tal que: 3x 2 (2k + 1)p 2 x (2k + 1)p 3 Dom f(x) – (2k + 1)p 3 Clave E 04 Como f(x) = sen2x + cos2x + tan2x x x – (2k + 1)p 2 Dom f = – (2k + 1)p 2 / k ∈ Clave B 05 Dando forma f(x) = atan2x + btanx Completando a cuadrados: f(x) = a tan2x + b a tanx = a tanx + b 2a 2 – b 2 4a Luego: 0 tanx + b 2a 2 < 0 a tanx + b 2a 2 < –b2 2a a tanx + b 2a 2 – b 2 4a < –b2 4a f(x) < Clave E 06 g(x) = ( 3tanx)2 + 2( 3tanx) 1 32 + 2 1 32 – 2 1 32 g(x) = 2 1 32 3tanx + – 1 12 g(x) = (6tanx + 1)2 12 – 1 12 Como x – p 4 ; p 4 –1 < tanx < 1 –6 < 6tanx < 6 –5 < 6tanx + 1 < 7 0 (6tanx + 1)2 < 49 0 (6tanx + 1)2 12 < 49 12 – 1 12 (6tanx + 1)2 12 – 1 12 < 48 12 – 1 12 f(x) < 4 Clave E 07 Como p 12 x p 2 p 6 2x p p 3 2x + p 6 7p 6 Y X 3 3 3/3 tan p 6 2x + –; 3 3 ] [ 3; + Clave C 08 Del dato: – p 4 < x p 4 – p 4 –x < p 4 0 p 4 – x < p 2 f(x) [0; mínimo = 0 Clave C 09 Cálculo del periodo: T = 2p = p B B = 1 2 (I) También p 3 ; 3 f(x) f p 3 = Atan p/3 2 = Atan p 6 3 = A 3 3 A = 3 y = f(x) = AtanBx = 3tan x 2 Clave E 10 h Y X – y = tan(Mx) Se observa T = 2p 3 x1 = p 6 También T = p M = 2p 3 M = 3 2 f(x) = tan 3 2 x h = f p 6 = tan p 6 3 2 · = tan p 4 = 1 Área = 1 2 4p 3 (1) = 2p 3 m2 Clave C TAREA 01 • tan p 3 = 3 • tan – p 6 = – 3 3 ⇒ Ranf = [– 3 3 ; 3 〉 02 • tanx = –1 ⇒ x = – p 4 • tanx = 1 ⇒ x = p 4 ⇒ Ranf = – p 4 ; p 4 03 f(x) = 2tanx 1 – tan2x ⇒ f(x)= tan2x Dom tan2x = – (2n + 1) p 4 , n ∈ p 3 p 6 p 4 p 4 –1 1 04 Domf(x) = ...; p 4 ; 5p 4 ; 9p 4 ; ... Domf(x) = kp + p 4 , k ∈ REFORZANDO 01 • tan – p 4 = 1 • tan p 3 = 3 ⇒ Ranf = 〈– 1; 3 ] Clave B 02 • x ∈ p 4 ; p 2 ⇒ f ∈ = [1 ; ∞〉 • x ∈ p 2 ; 5p 4 ⇒ f ∈ 〈–∞; 1] ⇒ Ranf = 〈–∞; 1] ∪ [1 ; ∞〉 Ranf = 〈–∞; + ∞〉 = Clave B 03 • f(x) = cotx ⇒ f(x) = 1 tanx ⇒ tanx ≠ 0 • tanx = 0 ⇔ x ∈ {..., –p; 0; p; 2p;....} x = kp, k ∈ ⇒ Domf(x) = – {kp}; k ∈ Clave E 04 • Se observa que el período de f(x) = tanAx es 2 p 5 • Se sabe que el período de tanx es p ⇒ A 2p 5 = p ⇒ A = 5 2 ∴ tanAx = tan 5 2 x Clave C 05 En la figura: a1 = p 3 ; a2 = p + p 3 , a3 = 2p + p 3 , ... ⇒ ai ∈ np + p 3 /n∈ Clave D p 4 5p 4 9p 4 1 tanx –1 p 3 p 4 3 p 4 p 2 5p 4 1 EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 44 06 • a = 9p 2 + p 6 a = 14p 3 • b = 11p 2 – p 6 b = 16p 3 ⇒ Domf(x) = 14p 3 ; 16p 3 Clave B 07 Ranf = [0 ; 3 ] Clave A 08 I. (V) Ran (tanx) = Ran (tan2x) = II. (V) y = tanx e y = |tanx| tienen las mismas asíntotas ⇒ tienen el mismo dominio. III. (V) El dominio depende de los va- lores que puede tomar x. En tanx y 2tanx, x puede tomar los mis- mo valores. Clave E 09 f(x) = tg3x – ctg3x + 1 = –2ctg6x + 1 x ∈ Dom(f) ⇔ x ∈ ∧ 6x ≠ np, n ∈ ⇔ x ∈ ∧ x ≠ np 6 , n ∈ [Dom(f )]° = np 6 /n∈ Clave D 10 f(x) = sec22x + 4ctg22x = sen22x + 4cos42x sen22xcos22x = 4(sen22x + 4cos42x) sen24x Entonces x ∈ Dom(f) ⇔ sen4x ≠ 0 Entonces Dom(f) = – np 4 /n∈ Clave E 11 Como x∈ 3p 10 , 5p 6 , ⇒ 1 4 ≤ 1 2 senx ≤ 1 2 ⇒ p 4 ≤ p 2 senx ≤ p 2 ⇒ 1 ≥ ctg p 1 2 senx ≥ 0 ⇒ Ran(f) = [0,1] Clave B 9p 2 p 3 p 3 10p 2 11p 2 – a b 3 3 p 6 p 12 3 3 p 4 – 3 Ranf f(x) = |tan2x| Tienen el mis- mo rango 12 f(x) = 2ctg2x tgx + 2 = 2 tgx 1 – tg2x 2tgx + 2 = = cot2x + 1 = csc3x ....... (I) Como x ∈ p 4 , p 3 ⇒ 2 3 ≤ cscx ≤ 2 y de (I) ⇒ Ranf(x) = 4 3 , 2 ∴ 3a – b2 = 0 Clave D 13 • Período de tanx es p: – tan2x: 2T1 = p ⇒ T1 = p 2 – tan3x: 3T2 = p ⇒ T2 = p 3 • Período de f(x) = tan2x + tan3x contiene a p 2 y p 3 ⇒ MCM p 2 , p 3 = p Clave A 14 Domf = – (2n + 1) p 4 /n ∈ p 6 2p 6 3p 6 g(x) = tan3x Domg = – (2n + 1) p 6 /n ∈ Domf ∩ Domg = = – (2n + 1) p 4 , (2n + 1) p 6 /n ∈ Clave A 15 f(x) = (cot2x + tan2x)2 – 4 + 5 = 4csc24x – 4 + 5 = 2 csc24x – 1 + 5 = 2|ctg4x|+ 5 ⇒ Ran(f) = [5, +∞〉 ∧ T = p 4 ⇒ secMT = sec 5p 4 = – 2 Clave B ACTIVIDADES CAP 24 FUNCIONES TRIGONOMÉTRICAS INVERSAS 01 I - V ; II - F ; III - V Clave E p 4 p 4 2p 4 3p 4 f(x) = tan2x – 02 H = –sen 1 2 arcsen 2 2 3 = –sen 1 2 q q q = arcsen 2 2 3 ⇒ senq = 2 2 3 q 1 2 23 H = –sen q 2 = – 1 – cosq 2 = – 1 – 1 3 2 H = – 3 3 Clave D 03 R = 6cos 2arccos 2 3 = 6cos2q q q = arccos 2 3 ⇒ cosq = 2 3 R = 6cos2q = 6{2cos2q – 1} = 6 2 2 3 – 1 R = 2 Clave B 04 E = (–2)arcsen cos p 2 + p 10 E = 2arcsen sen p 10 = 2 p 10 E = p 5 Clave E 05 x ∈ [–1 ; 1] – p 2 ≤ arcsenx ≤ p 2 ∧ 0 < arccotx < p ⇒ arcsenx – arccotx < p 2 Luego: [a ; b] = [–1 ; 1] ∴ a2 + b2 = 2 Clave D 06 E = sen(2arccosx) ⇒ E = sen2q q q = arccosx ⇒ cosq = E = 2senqcosq = 2( 1 – x2 )x 1 – x 2 x 1 q E2 = 4(1 – x2)x2 Clave D 07 M = tan(arctan(1) + arctan( 26 – 5)) + tan(arctan(1) + arctan – ( 26 – 5)) M = tan arc tan 1 + 26 – 5 1 – 26 + 5 + tan arc tan 1 – 26 + 5 1 + 26 – 5 M = 26 – 4 6 – 26 + 6 – 26 26 – 4 = 2 26 5 Clave E 08 f(x) = arcsen(2x – 1) + arccos(2x + 1) –1 ≤ 2x – 1 ≤ 1 ∧ –1 ≤ 2x + 1 ≤ 1 0 ≤ 2x ≤ 2 ∧ –2 ≤ 2x ≤ 0 0 ≤ x ≤ 1 ∧ –1 ≤ x ≤ 0 ∴ Domf = {0} Clave D EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 45 09 tan(arcsen 4 – x2 ) = sen(arctan2) q ω ⇒ tanq = senω q = arcsen 4 – x2 ⇒ senq = 4 – x2 ω = arctan2 ⇒ tanω = 2 Reemplazando: 4 – x2 x2 – 3 = 2 5 4 – x2 x2 – 3 = 4 5 ⇒ 3|x| = 4 2 Clave D 10 f(x) = |arcsenx|+|arctanx| ; x ∈ [–1 ; 1] – p 2 ≤ arcsenx ≤ p 2 ⇒ 0 ≤|arcsenx|≤ p 2 – p 4 ≤ arctanx ≤ p 4 ⇒ 0 ≤|arctanx|≤ p 4 Luego: ranf = 0 ; 3p 4 Clave C CUADERNO DE TRABAJO 01 b = arc sen 3 2 + arc cos 2 2 – arc tan 3 3 b = p 3 + p 4 – p 6 = 5p 12 Clave E 02 Por propiedad: arc cos(cosx) = x, 0 x p E = arc cos p 7 –sen = arc cos p 7 p 2 +cos E = arc cos 9p 14 cos E = 9p 14 Clave A 03 w = tan 1 2 2p 4 sen3arc cos w = tan 1 2 p 2 sen3arc cos 1 w = tan 1 2 3arc cos p/3 = tanp = 0 Clave A 04 cos(arc senx) + sen p 2 – arc senx = 3 2 cos(arc senx) + cos(arc senx) = 3 2 2cos(arc senx) = 3 2 cos(arc senx) = 3 4 arc senx = a sena = x cosa = 3 4 x = 1 – cos2a = 1 – 9 16 = 7 4 Clave A 05 arc cotx = arc cot 1 1 – x arc tan 1 x = arc tan 1 1 – x 1 x = 1 1 – x x2 = 1 – x x2 + x – 1 = 0 x = 2 –1 5 x = 2 –1 + 5 Clave A 06 f(x) = 3arc sen 3x – 4 5 + 5arc cos x2 – 2 2 + p 4 –1 3x – 4 5 ≤ 1 –1 x 2 – 2 2 1 – 1 3 x 3 0 x2 4 – 1 3 x 3 –2 x 2 x – 1 3 ; 2 El menor es – 1 3 Clave A 07 El dominio: –1 4x – 7 10 1 –3 4 x 17 4 x – 3 4 ; 17 4 Calculamos el rango: – p 2 arc sen 4x – 7 10 p 2 – 2p 15 2 3 arc sen 4x – 7 10 + p 5 8p 15 E – 2p 15 ; 8p 15 – 3 4 ; 17 4 ; – 2p 15 ; 8p 15 Clave A 08 Buscamos el dominio de f(x): f(x) = arc cosx + arc cotx x [–1; 1] x Dom f [–1; 1] Luego: 0 arc cosx p p 4 arc cotx 3p 4 (+) p 4 f(x) 7p 4 Comparando: m = p 4 ; M = 7p 4 M m = 7 Clave D 09 Si f(x) = p 2 arc sen x2 – 8 + p 3 arc cos x 4 0 x2 – 8 1 –1 x 4 1 8 x2 9 –4 x 4 x [–3; –2 2] [2 2; 3] x [–4; 4] x [–3; –2 2] [2 2; 3] = [–b; –a] [a; b] a2 + b2 = 17 Clave C 10 Calculamos los valores donde exista la función: f(x) = arc senx + arc cosx + arc tan(1/|x|+ 1) x [–1; 1] x [–1; 1] x x [–1; 1] Luego: f(x) = p 2 + arc tan 1 |x|+ 1 Partiendo: –1 x 1 0 |x| 1 1 |x|+ 1 2 1 2 1 |x|+ 1 1 arc tan 1 2 arc tan 1 |x|+ 1 p 4 f(x) p 2 + arc tan 1 2 ; 3p 4 Clave C TAREA 01 • f(0) = arc sen0 = 0 • f(0,5) = arc sen(0,5) = p 6 ⇒ f(0) + f(0,5) = 0 + p 6 = p 6 02 • f(1) = arc tan(1) = p 4 • f 3 3 = arc tan 3 3 = p 6 ⇒ f(1) + f 3 3 = p 4 + p 6 = 5p 12 03 Ranf = p 4 , p 3 04 • arc sena = p 4 ⇒ a = sen p 4 = 2 2 • arc sen(–1) = b ⇒ senb = –1 ⇒ b = – p 2 ⇒ a – b = 2 2 – p 2 = 2 – p 2 REFORZANDO 01 • f 3 2 = arc sen 3 2 = p 3 • f 2 2 = arc sen 2 2 = p 4 ⇒ f 3 2 + f 2 2 = p 3 + p 4 = 7p 12 Clave E 2 2 3 2 p 3 p 4 f(x) 4–x 2 x2–3 1 q 1 2 5ω EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 46 02 • f(–1) = arc tan(–1) = – p 4 • f( 3 ) = arc tan( 3 ) = p 3 ⇒ f(–1) + f( 3 ) = – p 4 + p 3 = p 12 Clave B 03 • f 1 3 = arc sen a 1 3 + arc sen β 2 3 ⇒ sena = 1 3 y senβ = 2 3 2 2 3 ⇒ cos a = 5 3 ⇒ cos β = • sen f 1 3 = sen(a + β) sen f 1 3 = senacosβ + senβcosa = 1 3 · 5 3 + 2 3 · 2 2 3 = 5 + 4 2 9 Clave B 04 • arc tan(2) = a ⇒ tana = 2 • arc tan(–3) = b ⇒ tanb = –3 • tan(a + b) = tana + tanb 1 – tanatanb tan(a + b) = 2 – 3 1 – 2(–3) = – 1 7 Clave E 05 Sea: a = arc sen 5 13 ∧ sena = 5 13 ∧ β = arc cos 1 5 ∧ cosβ = 1 5 Luego: M = tg(a + β) = 29 2 Así: csc pM 87 = csc p 6 = 2 Clave D 06 Sea: E = sen 1 2 arc sen – 2 2 3 E = – sen q 2 ; q = arc sen 2 2 3 – E = – 1 – 1 3 2 E = – 3 3 Clave D 5 a 13 12 ; tga = 5 12 2 β 1 ; tgβ = 25 2 q 3 1 2 ⇓ 07 Sea: q = arc tg x + 2 2 ∧ a = arc tg x 3 Luego: q – a ≥ p 4 ⇒ tg(q – a) ≥ tgp 4 x + 2 2 x + 2 2 x 3 x 3 – 1 + ≥ 1 x(x + 1) ≤ 0 ∴ x ∈ [–1 ; 0] Clave A 08 – 1 ≤ 1 –|x| ≤ 1 ∧ –1 ≤ x + 2 3 ≤ 1 |x| ≤ 2 ∧ –3 ≤ x + 2 ≤ 3 –2 ≤ x ≤ 2 ∧ –5 ≤ x ≤ 1 Domf = [–2, 2] ∩ [–5, 1] = [–2 ; 1] Clave B 09 arctanp + arctanq + arctanr = p ... (I) φ = arctanp ⇒ tanφ = p ω = arctanq ⇒ tanω = q ... (II) r = arctanr ⇒ tanr = r (II) en (I): φ + ω + r = p ⇒ tanq + tanω + tanr = tanqtanωtanr Reemplazando: p + q + r = pqr ∴ p + q + r pqr = 1 Clave B 10 Como: – 1 ≤ 3x – 4 5 ≤ 1 ∧ – 1 ≤ x 2 – 2 2 ≤ 1 –5 ≤ 3x – 4 ≤ 5 – 2 ≤ x2 – 2 ≤ 2 – 1 3 ≤ x ≤ 3 – 2 ≤ x ≤ 2 ∴ x ∈ – 1 3 ; 2 Clave A 11 g(x) = p 6 + arc sen x – 1 2 + arc cos(2x + 2) – 1 ≤ x – 1 2 ≤ 1 ∧ –1 ≤ 2x + 2 ≤ 1 –2 ≤ x – 1 ≤ 2 ∧ –3 ≤ 2x ≤ –1 –1 ≤ x ≤ 3 ∧ – 3 2 ≤ x ≤ – 1 2 ⇒ Dom(g) = – 1 ; – 1 2 Clave A 12 g(x) = arc tg1 2 + arc tg1 4 + arc tg1 8 tg[g(2)] = 1 8 1 8 1 4 1 4 1 8 1 8 1 4 1 4 1 2 1 2 1 – 1 – + + + 1 – = 11 10 Clave A 13 Como x ∈ 1 + 3 2 ; + ∞ ⇒ 2 + 3 ≤ 2x 5p 12 ≤ arc tg2x < p 2 25p 12 ≤ f(x) < 5p 2 Ran(f) = 25p 12 ; 5p 2 Clave A 14 A = 1 + tg2 arc tg – 1 2 + 1 – cos2 arc cos 7 8 + 1 – sen2 arc sen 3 8 = 1 + 1 4 + 1 – 7 8 + 1 – 3 8 = 3 + 1 4 – 5 4 A = 2 Clave B 15 Como x ∈ – 1 4 ; 3 4 ⇒ – 1 4 ≤ x ≤ 3 4 ⇒ – 1 2 ≤ 2x ≤ 3 2 ⇒ – p 6 ≤ arc sen2x ≤ p 3 ⇒ – p 3 ≤ 2arc sen2x ≤ 2p 3 ⇒ – p 3 + p 6 ≤ 2arc sen2x + p 6 ≤ 2p 3 + p 6 ⇒ – p 6 ≤ f(x) ≤ 5p 6 ⇒ f(x) ∈ – p 6 ; 5p 6 min f(x) = – p 6 Clave A ACTIVIDADES CAP 25 GRÁFICA DE LAS FUNC. TRIGON. INVERSAS 01 A = 1 3 – – 1 3 ⇒ = 2 3 2 3 arccosB(0) + C = 0 2 3 p 2 + C = 0 ⇒ C = – p 3 2 3 arccosB(8) – p 3 = – p 3 ⇒ B = 1 8 ∴f(x) = 2 3 arccos x 8 – p 3 Clave B 02 f(–1) = arccos(–1) = p Área de la región sombreada: S S = 1 2 [2(p)] S = p u2 Clave D EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 47 03 y = karccosBx ⇒ k = 4 Área de la región sombreada: S S = 1 2 [8(4p)] ⇒ S = 16p Sk = 64p Clave D 04 f(x) = 4arctanx Clave C 05 y = arccosx ⇒ cosy = x y = arctanx ⇒ tany = x cosy = x ⇒ 1 1 + x2 = x 1 xy1 + x 2 x 1 + x2 = 1 ⇒ x2(1 + x2) = 1 Luego: x 2 sen2y + seny = x 2 2senycosy + seny = x 1 1 + x2 1 1 + x2 + x 1 + x2 = x4 x2(1 + x2) + x2 x 1 + x2 ∴ x 2 sen2y + seny = x4 + x2 = x2(1 + x2) = 1 Clave B 06 Área de la región: S = p 2 (2) ∴ S = pu2 Y X p 2 p 2 p/2 11 –1 –arc senx –arc cosx 10 S p – Clave A 07 x ≥ 2 ⇒ 0 < 1 x ≤ 1 2 0 < arcsen 1 x ≤ p 6 p 3 < 2arcsen 1 x + p 3 ≤ p 3 + p 3 p 3 < f(x) ≤ 2p 3 ∴ a + b = p 3 + 2p 3 = p Clave A 08 x ≥ 2 ⇒ 0 < 1 x ≤ 1 2 0 < arcsen 1 x ≤ p 6 p 6 < 3arcsen 1 x + p 6 ≤ p 2 + p 6 ∴ 2(b – a) = 2 4p 6 – p 6 = p Clave A 09 f(x) = sen2 p 2 + arcsenx = sen2(arccosx) f(x) = 1 – cos2(arccosx) = 1 – x2 x ∈ [–1 ; 1] Y X O 1 1 –1 Clave D 10 f(x) = arccos(sen4x + cos4x) f(x) = arccos(1 – 2sen2xcos2x) 0 ≤ sen2xcos2x ≤ 1 –2 ≤ –2sen2xcos2x ≤ 0 –1 ≤ 1 – 2sen2xcos2x ≤ 1 p ≤ arccos(1 – 2sen2xcos2x) ≤ 0 ∴ Ranf = [0 ; p] Clave B CUADERNO DE TRABAJO 01 Como – p 2 arc senBx p 2 – Ap 2 Aarc senBx Ap 2 –p p A = 2 Luego: –1 Bx 1 – 1 B x 1 B –2 2 B = 1 2 y = f(x) = 2arc sen x 2 Clave E 02 Como –1 x – 2 5 1 –3 < x 7 También: 0 arc cos x – 2 5 p 0 3arc cos x – 2 5 3p 10 –3 70 Y X Piden el área: b×h = 10 3p 2 = 15p Clave D 03 Trasladando áreas tenemos: Área sombreada: b×h = 1(2A) = 4p A = 2p A –A Y X –1 1 Clave B 04 y = f(x) = 2arc sen2x + p –1 2x 1 1 2 x 1 2 También: – p 2 arc sen2x p 2 1 2 – 1 2 Y X 0 arc sen2x + p 2p Clave C 05 En el punto P las ordenadas de ambas funciones son iguales, entonces: g(x) = f(x) arc senx = arc cosx = p 2 – arc senx 2arc senx = p 2 arc senx = p 4 y = arc senx = p 4 Clave B 06 Dato: A TOP = p 3 (1)(y) 2 = p 3 y = 2p 3 arc cosx = 2p 3 x = cos 2p 3 = – 1 2 Y Q R T O P X y x–1 11 En el TQR: A = 1 2 b×h = 1 2 1 2 (p – y) = 1 4 2p 3 p – = p 12 Clave E 07 Como y = f(x) = arc senx y = arc sena (I) También: y = 1 – a (II) Igualando (I) y (II): Y X 1 – a y a 1 1 – a = arc sena a + arc sena = 1 Clave E 08 arc cos 1 2 = p 3 arc tan(1) = p 4 También arc cosx = p 2 – arc senx Luego en: f(x) = p 3 – p 4 + 2p p 2 – arc senx arc senx f(x) = p2 arc senx – 23p 12 (I) Como x 1 2 ; 3 2 p 6 arc senx p 3 1 2 Y X 3 2 3 p 1 arc senx 6 p Luego: 13p 12 f(x) 49p 12 a f(x) b b – a = 3p Clave D 09 Y X – x1–x1 y = f(x) =|arctanx| y = f(x) = arccosx Por la simetría se observa que si x1 es so- lución – x1 como solución. La suma de soluciones en [–8p; 8p] es cero. Clave D 10 Si y = f(x) = x x 0 arc tan2x – 5arc tanx + 4 0 arc tanx –4 arc tanx –1 arc tanx –; 1] [4; O EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 48 ¡Pero! arc tanx – p 2 ; p 2 Interceptando se tiene: arc tanx – p 2 ; 1] Y X – x 1 x –∞; tan1] ∪ [tan4 ; ∞〉 Clave B TAREA 01 x f(x) = arc senx –1 –p/2 0 0 1 p/2 02 x f(x) = arc sen2x – 1 2 – p 0 0 1 2 p 03 x f(x) = arc cos x 2 –2 p 0 p/2 2 0 04 x f(x) = 2arc senx –1 2 – p 2 = –p 0 2(0) = 0 1 2 p 2 = p REFORZANDO 01 El gráfico de f(x) = arc tanx es: Clave B –1 p 2 – 1 p 2 – –p p 1 2 1 2 p 2 –2 2 p –p p –1 1 0 p 2 – p 2 02 El gráfico debe estar trasladado 1/4 hacia la derecha. Entonces: a = 1 4 Clave A 03 El gráfico está trasladado p 2 unidades ha- cia arriba, entonces la función es: f(x) = arc senx + p 2 Clave C 04 El gráfico puede corresponder a: f(x)= –arc senx Clave A 05 El gráfico corresponde a la función: f(x) = 2arc sen2x Clave D 06 • arc sena = p 6 ⇒ a = 1 2 • arc senb = p 4 ⇒ b = 2 2 ∴ a + b = 1 + 2 2 Clave C 07 El gráfico de f(x) = arc tan2x es: Clave B 08 • a = 2 arc sen 2 3 ⇒ a 2 = arc sen 2 3 • a = 2 arc cosb ⇒ a 2 = arc cosb ⇒ cos a 2 = b ⇒ b = 5 3 Clave C 09 • f(x) = Aarc tanBx • Del gráfico A = 2 • Del gráfico f(2) = p 2 ⇒ p 2 = 2 arc tanB(2) ⇒ p 4 = arc tan (2B) ⇒ 2B = 1 ⇒ B = 1 2 ∴ A + B = 2 + 1 2 = 5 2 Clave D 10 • f(x) = Aarc cosBx f(–1) = p f(0) = 3p 2 0 p 4 – p 4 2 a/2 3 5 • 3p 2 = Aarc cos(0) 3p 2A = arcos0 ⇒ 3p 2A = p 2 ⇒ A = 3 • p = 3arc cos(–B) ⇒ cosp 3 = –B ⇒ B = – 1 2 ∴ A + B = 3 – 1 2 = 5 2 Clave D 11 El gráfico de f(x) = arc cot2x es: Clave C 12 Sea: f(x) = Aarc cos(Bx + C) + D pA = 11p 6 + 2p 3 = 5p 2 ⇒ A = 5/2 2 B = 8 – 2 ⇒ B = 1 3 C B = 2 + 8 2 ⇒ C = 5 3 D = – 2p 3 ∴ f(x) = 5 2 arc cos x 3 – 5 3 – 2p 3 Clave C 13 El gráfico de f(x) = –3arc cot2x es: Clave D 14 La función es f(x) = 2 arc sen3x, pero re- flejado respecto a Y y trasladado p 6 hacia la izquierda, entonces es: f(x) = –2arc sen3 x + p 6 3p p 2p 3p/2 –1 1 2 0 –4p 4p 2 8C/B D pA 2/B 11p 6 – 2p 3 0 –6p –3p EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 49 f(x) = –2arc sen 3x + p 2 Clave E 15 S = AB · PH 2 S = p + p 2 1 – 2 2 1 2 S = 3p 8 (2 – 2) A P B H y = arc cosx y = arc senx p –p/2 p/2 p/4 –1 12 2 Clave D ACTIVIDADES CAP 26 ECUACIONES TRIGONOMÉTRICAS 01 sen2x = 1 2 ⇒ VP = 30° = p 6 2x = kp + (–1)k p 6 x = k p 2 + (–1)k p 12 k = 0 ⇒ x = p 12 ; k = 1 ⇒ x = 5p 12 ∴ p 12 + 5p 12 = p 2 = 90° Clave B 02 cos(3x – 30°) = 3 2 ⇒ 3x – 30° = 30° 3x = 60° Luego: 3x = 2kp ± 60° x = 2p 3 k ± 20° = 120°k ± 20° k = –1 x = –100° x = –140° ; k = 0 x = 20° x = –20° k = 1 x = 140° x = 100° ∴ ∃ 7 soluciones Clave B 03 tan(3x – 15°) = –1 ⇒ 3x – 15° = –45° 3x = –30 Luego: 3x = kp + (–30°) x = k p 3 – 10° = 60°k – 10° k = –5 ⇒ x = –310° ; k = –4 ⇒ x = –250° k = –3 ⇒ x = –190° ; k = –2 ⇒ x = –130° k = –1 ⇒ x = –70° ; k = 0 ⇒ x = –10° k = 1 ⇒ x = 50° ; k = 2 ⇒ x = 110° k = 3 ⇒ x = 170° ; k = 4 ⇒ x = 230° k = 5 ⇒ x = 290° ; k = 6 ⇒ x = 350° ∴ ∃ 13 soluciones Clave D 04 tan3x = – 3 ⇒ VP = –60° 3x = kp + (–60°) ⇒ x = 60°k – 20° k = 0 ⇒ x = –20° Clave B 05 sen3x = 2 2 ⇒ VP = p 4 Luego: 3x = kp + (–1)k p 4 ⇒ x = 60°k + 15°(–1)k k = 0 ⇒ x = 15° ; k = –1 ⇒ x = – 75° Donde: a = –75° ⇒ 2a = –150° sen2a = sen(–150°) = –sen30° ∴ sen2a = – 1 2 Clave B 06 2sen23x = 2 1 – cos6x = 2 cos6x = – 1 ⇒ VP = p Luego: 6x = 2pk ± p ∴ x = (2k ± 1) p 6 Clave D 07 (tan2x – 3)(2senx – 1) = 0 • tan2x = 3 ⇒ VP = 60° 2x = kp + 60° ⇒ x = 90°k + 30° k = 0 ⇒ x = 30° • senx = 1 2 ⇒ VP = 30° x = kp + (–1)k30° k = 0 ⇒ x = 30° Clave E 08 sen5x = 2 2 ⇒ VP = p 4 = 45° 5x = k(180°) + (–1)k45° ⇒ x = 36°k + (–1)k9° k = –1 ⇒ x = –45° ; k = 0 ⇒ x = 9° Clave D 09 cotx – 2cotxsenx = 0 cotx(1 – 2senx) = 0 • 1 – 2senx = 0 ⇒ senx = 1 2 ⇒ VP = 30° = p 6 Luego: x = kp + (–1)k p 6 k = –1 ⇒ x = – 7p 6 • cotx = 0° ⇒ x = – p 2 Clave D 10 (2cos2x + 1) sen3x – 3 2 = 0 • cos2x = – 1 2 ⇒ VP = 2p 3 = 120° 2x = 2pk ± 2p 3 ⇒ x = kp ± p 3 k = 0 ⇒ x = p 3 ; k = 1 ⇒ x = 2p 3 • sen3x = 3 2 ⇒ VP = p 3 3x = kp + (–1)k p 3 ⇒ x = k p 3 + (–1)k p 9 k = 0 ⇒ x = p 9 ; k = 1 ⇒ x = 2p 9 k = 2 ⇒ x = 7p 9 ; k = 3 ⇒ x = 8p 9 ∴ p 3 + 2p 3 + p 9 + 2p 9 + 7p 9 + 8p 9 = 3p Clave E CUADERNO DE TRABAJO 01 De la ecuación: sen x 2 = – 1 2 Vp = –30° Luego x 2 = 180k + (–1)k(–30°) x = 360°k + (–1)k(–60°) k = 0 x = –60° Mayor k = 1 x = 420° k = 2 x = 660° k = –1 x = –300° Menor Piden la diferencia entre la mayor y me- nor solución: –60° – (–300°) = 240° Clave B 02 Se tiene: cos(2x – 15)° = 2 2 Vp = –45° Luego aplicamos solución general: 2x – 15° = 360°k Vp = 360°k 45° k = 0 x = 30° = –15° k = –1 x = –150° = –195° k = –2 x = –330° = –375° x = { –330°; –195°; –150°; –15°} Menor solución negativa = –330° Clave C 03 De la ecuación: cos2x = 1 Vp = 0 Luego 2x = 2kp Vp 2x = 2kp x = kp/k Clave C 04 De la ecuación: tan3x = – 3 Vp = – p 3 Luego 3x = kp + Vp 3x = kp – p 3 x = kp 3 – p 9 ; k ∈ Clave E 05 De la ecuación: cos x 2 = 1 + 0 + (–1) = 0 cos x 2 = 0 Vp = p 2 Luego: x 2 = 2kp p 2 x = 4kp p Si k = 0 x = –p x = p ( al intervalo pedido) Si k = 1 x = 3p x = 5p Clave A 06 De la ecuación: tan25x = 1 tan5x = 1 i) tan5x = 1 Vp = p 4 Luego: 5x = kp + Vp 5x = kp + p 4 x = kp 5 + p 20 k = 0 ⇒ x = p 20 k = 1 ⇒ x = p 4 EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 50 k = 2 ⇒ x = 9p 20 k = 3 ⇒ x = 13p 20 k = 4 ⇒ x = 17p 20 ii) tan5x = –1 Vp = – p 4 Luego: 5x = kp – p 4 x = kp 5 – p 20 k = 1 x = 3p 20 k = 2 x = 7p 20 k = 3 x = 11p 20 k = 4 x = 15p 20 k = 5 x = 19p 20 Clave E 07 Igualando cada factor a cero: i) 2senx + 1 = 0 senx = – 1 2 Vp = –30° Luego: x = 180°n + (–1)n(–30°) n = 0 x = –30° n = 1 x = 210° n = 2 x = 330° ii) senx – 1 = 0 senx = 1 x = 90° soluciones: 210° + 330° + 90° = 630° Clave B 08 3tan2x – 3 = 0 tan2x = 3 3 = 3 Vp = 60° Luego: 2x = 180°k + Vp 2x = 180°k + 60° x = 90°k + 30° Si k = 0 x = 30° k = 1 x = 120° k = 2 x = 210° k = –1 x = –60° k = –2 x = –150° k = –3 x = –240° Piden: –150° – 60° + 120° + 30° = –60° = – p 3 Clave B 09 Si senx – cosx = 0 senx = cosx tanx = 1 Vp = 45° Luego: x = 180°n + Vp x = 180°n + 45° n = –2 x = –315° n = –1 x = –135° n = 0 x = 45° n = 1 x = 225° 2 soluciones. Clave C 10 (sen3x – 3)(sen3x + 1) = 0 i) sen3x = 3 ...(No existe solución) ii) sen3x = –1 Vp = – p 2 Luego: 3x = kp + (–1)k p 2 – x = kp 3 + (–1)k + 1 p 6 Clave D TAREA 01 cos2x = 3 2 ⇒ Vp = p 6 ⇒ 2x = 2np ± p 6 ⇒ x = np ± p 12 , n ∈ 02 2senxcosx =2 1 4 ⇒ cos2x = 1 2 ⇒ 2x = p 3 ⇒ x = p 6 03 cos2x – sen2x = 2 2 ⇒ cos2x = 2 2 ⇒ 2x = p 4 ⇒ x = p 8 04 (1 + sen2x)cos2x = 0 (2+2sen2x)2cos2x = 0 (2 + 1 – cos2x) (1 + cos2x) = 0 (3 – cos2x) (1 + cos2x) = 0 ⇒ cos2x = 3 ∨ cos2x = –1 ⇒ VP = p descartado ⇒ 2x = 2pk ± p ∴ x = pk ± p 2 / k ∈ REFORZANDO 01 tan4x = cos p 2 ⇒ tan4x = 0 ⇒ Vp = 0 ⇒ 4x = kp , k ∈ ∴ x = kp 4 ; k ∈ Clave D 02 sen2x = sen36° – cos54° ⇒ sen2x = 0 0 ⇒ Vp = 0 Entonces: 2x = {kp/k ∈ } ∴ x = kp 2 ; k ∈ Clave E 03 (2 + sen2x) ≠ 0 (2senx – 1) = 0 ⇒ senx = 1 2 ⇒ x = p 6 , 5p 6 ⇒ La suma es p Clave C 04 sen2x – sen245° = 0 ⇒ sen2x = 1 2 ⇒ Vp = p 6 2x = kp + (–1)k × p 6 , k ∈ ∴ x = kp 2 + (–1)k × p 12 , k ∈ Clave A 05 tan2x = 2 · tanx – 1 : x ∈ [0; 2] tan2x – 2 · tanx + 1 = 0 (tanx – 1)2 = 0 → tanx = 1 tanx = tan p 4 ⇒ Vp = p 4 Luego: x = kp + p 4 ; k ∈ k = 0 ⇒ x = p 4 ; k = 1 ⇒ x = 5p 4 ∴ p 4 + 5p 4 = 3p 2 Clave B 06 (2sen2x + 1) (sen2x – 2) ≠0 = 0 ⇒ sen2x = – 1 2 ⇒ 2 = – 5p 6 ⇒ x = – 5p 12 Clave B 07 sen4xcos2x – cos4xsen2x sen2xcos2x = 2 ⇒ sen(4x – 2x) sen2xcos2x= 2 ⇒ sen2x sen2xcos2x = 2 ⇒ sec2x = 2 ⇒ cos2x = 1 2 ⇒ 2x = p 3 ⇒ x = p 6 Luego: a = p 6 ⇒ tg2a = 3 Clave C 08 cos4x – cos2x – sen3x = 0 ⇒ –2sen3xsenx – sen3x = 0 ⇒ –sen3x(2senx + 1) = 0 sen3x = 0 ∨ 2senx + 1 = 0 ⇒ + p 3 + – p 6 = p 3 – p 6 = p 6 Clave D 09 2cos2x = sen(x + 36°) – sen(x – 36°) 2cos2x = 2cosx sen36° cosx(cosx – sen36°) = 0 ⇒ cosx = 0 ∨ cosx = sen36° = cos54° ⇒ x = (2k + 1)p 2 ∨ x = 2pk ± 3p 10 ⇒ La menor solución positiva es 3p 10 Clave E 10 (1 – cos2x) + (1 – cos4x) + (1 – cos8x) = 0 ⇒ sen2x + sen22x + sen24x = 0 ⇒ senx = sen2x = sen4x = 0 ⇒ x = np , 2x = np , 4x = np , n ∈ ⇒ C.S. = {np/n ∈ } Clave D sen3x = 0 ⇒ x = ± p 3 senx = – 1 2 ⇒ x = – p 6 , x = 7p 6 EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 51 11 cotx tany = 3 ⇒ tany = 3tanx tanx – tany = 1 – 3 ⇒ tanx – 3tanx = 1 – 3 ⇒ tanx(1 – 3) = 1 – 3 ⇒ tanx = 1 ∴ x = kp + p 4 , k ∈ Clave B 12 1 – 2sen2x + 5senx – 5cosx = 0 Recordemos que (senx – cosx)2 = 1 – sen2x Entonces: (senx – cosx)2 + 5(senx – cosx) = 0 (senx – cosx)2 + 5(senx – cosx) = 0 (senx – cosx) (senx – cosx + 5) ≠0 = 0 De donde solo es posible senx – cosx = 0 ⇒ senx = cosx tanx = 1 ∴ x = kp + p 4 k ∈ Clave B 13 2sen3x – 4sen2x – senx + 2 = 0 Factorizamos 2sen2x(senx – 2) – (senx – 2) = 0 (senx – 2) ≠ 0 (2sen2x – 1) = 0 ⇒ 2sen2x – 1 = 0 → cos2x = 0 2x = (2k ± 1) p 2 ; k ∈ x = (2k ± 1) p 4 ; k ∈ Clave B 14 senxcos5x – sen5xcosx = 1 8 senxcosx(cos4x – sen4x) = 1 8 senxcosx(cos2x + sen2x)(cos2x – sen2x) = 1 8 sen2x 2 × (cos2x) = 1 8 sen4x 4 = 1 8 → sen4x = = 1 2 Entonces: 4x = np + (– 1)n p 6 ; n ∈ ∴ x = np 4 + (– 1)n p 24 ; n ∈ Clave C 15 sen2q + cos2q ≥ 3 + 2 (senq – cosq) (sen2q – 2senq) + (cos2q + 2cosq – 3) ≥ 0 (2senqcosq – 2senq) + ((2cos2q – 1) + 2cosq – 3) ≥ 0 2senq(cosq – 1) + (2cos2q + 2cosq – 4) ≥ 0 2senq(cosq – 1) + (2cosq + 4)(cosq – 1) ≥ 0 2(cosq – 1) · (senq + cosq + 2) (+) ≥ 0 cosq – 1 ≥ 0 → cosq ≥ 1 Entonces: cosq = 1 ∴ q = 2kp , k ∈ Clave A ACTIVIDADES CAP 27 ECUACIONES TRIGONOMÉTRICAS NO ELEMENTALES 01 2sen2xcos3x = 2cos3x cos3x(sen2x – 1) = 0 sen2x = 1 ⇒ Vp = p 2 2x = kp + p 2 ⇒ x = k p 2 + p 4 ; k ∈ Clave D 02 2cos6xcos2x = 0 cos6x = 0 Vp = p 2 6x = kp ± p 2 ⇒ x = k p 3 ± p 12 ; k ∈ k = 0 ⇒ x = p 12 ⇒ a = p 12 Luego: sen2a = sen p 6 = 1 2 Clave B 03 2senxcosx = cosx cosx(2senx – 1) = 0 senx = 1 2 ⇒ VP = p 6 x = kp + (–1)k · p 6 k = 0 ⇒ x = p 6 ; k = 1 ⇒ x = 5p 6 cosx = 0 ⇒ Vp = p 2 x = 2pk ± p 2 k = 0 ⇒ x = p 2 ; k = 1 ⇒ x = 3p 2 Suma: p 6 + 5p 6 + p 2 + 3p 2 = 3p Clave C 04 2senxcosx + 2cos2xsenx = 0 2senx(cosx + cosx) = 0 senx(2cos2x + cosx – 1) = 0 senx(2cosx – 1)(cosx + 1) = 0 cosx = 1 2 ⇒ x = p 3 Clave A 05 (sen2x + cos2x)(sen2x – cos2x) = 1 – cos2x = 1 cos2x = – 1 ⇒ Vp = p 2x = 2pk ± p ⇒ x = pk ± p 2 k = 0 ⇒ x = p 2 ; x = – p 2 ⇒ a = – p 2 sen3a – cos2a = – (–1) = 2 Clave D 06 sec2(2x) – tan2(2x) – tan2(2x) – 1 = 0 1 tan2(2x) = 0 ⇒ tan2x = 0 ⇒ Vp = 0 2x = kp + 0 ⇒ x = k p 2 k = 1 ⇒ x = p 2 ; k = 2 ⇒ x = p ; k = 3 ⇒ x = 3p 2 Suma: p 2 + p + 3p 2 = 3p Clave B 07 cot4x – 2cos2x – sen2x sen2x = 0 cot4x – 2cot2x + 1 = 0 (cot2x – 1)2 = 0 cot2x = 1 ⇒ 1 tan2x = 1 ⇒ tan2x = 1 tanx = ± 1 ⇒ Vp = ± p 4 Luego: x = kp ± p 4 k = 0 ⇒ x = p 4 ; k = 1 ⇒ x = 3p 4 ; x = 5p 4 k = 2 ⇒ x = 7p 4 ∴ ∃ 4 soluciones Clave C 08 2senxcos2x + senx = 2coxcos2x – cosx sen3x – senx + senx = cos3x + cosx – cosx sen3x = cos3x ⇒ tan3x = 1 ⇒ Vp = 45° = p 4 Luego: 3x = kp + p 4 ⇒ x = k p 3 + p 12 k = 0 ⇒ x = p 12 ; k = 1 ⇒ x = 5p 12 ; k = 2 ⇒ x = 9p 12 ; k = 3 ⇒ x = 13p 12 no cumple Suma: p 12 + 5p 12 + 9p 12 = 5p 4 Clave E 09 tan3x + tan2x + tan5xtan3x + tan2x = 3 tan5x tan5x = 3 ⇒ 5x = 60° ∴ x = 12° Clave C 10 senpx – cospx > 0 2sen px – p 4 > 0 sen px – p 4 > 0 ; I y II Cuadrante x ∈ [0 ; 2] ∧ 0 < px – p 4 < p 0 ≤ x ≤ 2 ∧ 0 < x – 1 4 < 1 1 4 < x < 5 4 Luego: [0 ; 2] ∩ 1 4 ; 5 4 = 1 4 ; 5 4 Clave B EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 52 CUADERNO DE TRABAJO 01 Aplicando las transformaciones: 2sen9x cos4x = 3(2cos9x cos4x) cos4x(tan9x – 3) = 0 i) cos4x = 0 4x = p 2 x = p 8 ii) tan9x = 3 9x = p 3 x = p 27 La menor solución positiva es p 27 . Clave A 02 De la ecuación: senq + cosq = –1 2sen p 4 q + = –1 sen p 4 q + = – 1 2 Y C.T. X 3 q + p 4 = 3p 4 ; 7p 4 q = p 2 ; 3p 2 Suma = 2p Clave A 03 6sen(2x) – 8cosx + 9senx – 6 = 0 12senx cosx – 8cosx + 9senx – 6 = 0 Factorizando: 4cosx(3senx – 2) + 3(3senx – 2) = 0 (3senx – 2)(4cosx + 3) = 0 Como x – p 2 ; p 2 : senx = 2 3 Como senx > 0 x 0; p 2 Por lo tanto, existe un único valor para x. Clave A 04 sen2x secx = 1 2senx cosx secx = 1 2senx cosx 1 cosx = 1 Entonces: cosx 0 x (2n + 1)p 2 Luego: 2senx = 1 senx = 1 2 x = 30° Clave B 05 Cálculo de a: sen42x – sen24x = cos24x – cos42x sen42x + cos42x = sen24x + cos24x = 1 3 4 + cos8x 4 = 1 cos8x = 1 8x = 2p x = p 4 Luego la mayor raíz de: x2 – (5tana)x + 6tana = 0, tana = 1 x2 – 5x + 6 = 0 x –3 x = 3 (mayor raíz) x –2 x = 2 Clave E 06 Por propiedades: (1 + sen2x)2 + cos22x + tan2x = sec2x Desarrollando el binomio al cuadrado y llevando tan2x al 2° miembro, formamos las identidades trigonométricas siguientes: 1 + 2sen2x + (sen22x + cos22x) 1 = 1 1 + 2sen2x = 0 sen2x = – 1 2 Clave E 07 Factorizando la ecuación: 2sen3x + sen2x – 2senx – 1 = 0; 0 x 2p sen2x(2senx + 1) – (2senx + 1) = 0 (2senx + 1)(sen2x – 1) = 0 I. senx = – 1 2 x = 7p 6 ; 11p 6 II. senx = 1 x = p 2 III. senx = –1 x = 3p 2 Entonces la solución es: x1 + x2 + x3 + x4 = 5p Clave A 08 Usando: cos4q = 3 + 4cos2q + cos4q 8 En el problema: 3 + 4cosx + cos2x 8 – cos2x 8 = 7 8 3 + 4cosx = 7 cosx = 1, x = 2np, n x = {0; 2p} Número de soluciones: 2 Clave B 09 Tenemos: (senq)x – y = 0 (1) x + (4cosq)y = 0 (2) Para que el sistema admita más de una solución, estas ecuaciones deben de veri- ficar que: senq 1 = –1 4cosq 2senq cosq = – 1 2 sen2q = – 1 2 Dado que se pide el menor valor positivo: 2q IIIC 2q = 180° + 30° q = 105° Clave B 10 De sen(px) – cos(px) < 0 2sen p 4 px – < 0 sen p 4 px – < 0 Como x 1; 3 sen < 0 sen < 0 Y X C.T. p < px < 3p 3p 4 < px – p 4 < 11p 4 ...(I) ¡Pero! sen p 4 px – < 0 p < px – p 4 < 2p ...(II) Intersectando I y II: 3p 2 ; 11p 2 ∩ 〈p ; 2p 〉 p < px – p 4 < 2p 5 4 < x < 9 4 Clave B TAREA 01 cos2x + cos2x – 1 = 1 2cos2x – 1 = 1 ⇒ cos2x = 1 ⇒ 2x = p ⇒ x = p 2 02 Por legendre: 4senxcosx = 1 ⇒ 2senxcosx = 1 2 sen2x = 1 2 ⇒ Vp = p 6 ⇒ 2x = np + (–1)n p 6 ⇒ x = np 2 + (–1)n p 12 , n ∈ 03 En 1 – cos4x secx = 0, como secx = 1 cosx ⇒ cosx≠0 para que secx esté definido ⇒ cosx ≠ 0 y x ∈ 0, 3p 2 ⇒ x ≠ p 2 En 1 – cos4x = 0 ⇒ cos4x = 1, pero 0 ≤ x ≤ 3p 2 ⇒ 0 ≤ 4x ≤ 6p ⇒ 4x = 0 ; 2p ; 4p ⇒ x = 0; p 2 ; p , pero x ≠ p 2 ⇒ x = 0; p 04 5sen4x –(1 – 2sen24x) + 3 = 0 2sen24x + 5sen4x + 2 = 0 (2sen4x + 1) (sen4x + 2) ≠ 0 = 0 ⇒ 2 sen4x + 1 = 0 ⇒ sen4x = –1 2 ; Vp = –p 6 ⇒ 4x = np +(–1)n – p 6 ⇒ x = np 4 + (–1)n+1 p 24 ⇒ x = p 4 n + (–1)n+1 6 , n ∈ REFORZANDO 01 cos4x – sen4x = 1 (cos2x + sen2x) 1 (cos2x – sen2x) cos2x = 1 ⇒ cos2x = 1 ⇒ 2x = 2np ⇒ x = np , n ∈ Clave A EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 53 02 2cos2x + sen2x = 0 2cos2x + 2senxcosx = 0 2cosx(cosx + senx) = 0 cosx = 0 ⇒ x = p 2 tanx = –1 ⇒ x = 3p 4 ∴ menor solución = p 2 Clave B 03 (2sen3x – senx) – 2cos2x = 0 senx(2sen2x – 1) – 2cos2x = 0 senx(–cos2x) – 2cos2x = 0 –cos2x(senx + 2) ≠0 = 0 ⇒ cos2x = 0 ⇒ 2x = – p 2 ⇒ x = – p 4 Clave C 04 sen3x + senx cos3x + cosx = 3 ⇒ 2sen2xcosx 2cos2xcosx = 3 cosx ≠ 0 ⇒ x ≠ (2n + 1) p 2 ⇒ tg2x = 3 ⇒ x = np 2 + p 6 , n ∈ Número de soluciones es 2 Clave B 05 ctgx + tgx – 4ctg2x = 0 ⇒ 2csc2x – 4cos2x sen2x = 0 ⇒ 1 – 2cos2x sen2x = 0 ⇒ 1 – 2cos2x = 0 ⇒ cos2x = 1 2 Entonces la menor solución positiva es p 6 Clave C 06 cos5xcos3x = cosxcos7x ⇒ (cos8x + cos2x) – (cos8x + cos6x) = 0 ⇒ cos2x – cos6x = 0 ⇒ 2sen4xsen2x = 0 ⇒ x = np 4 ∨ x = np 2 , n ∈ Clave B 07 tanx = cot(2x + a) Si tana = cotq ⇒ a + q = (2k + 1) p 2 / k ∈ ⇒ 3x + a = (2k + 1) p 2 / k ∈ x = (2k + 1) p 6 – a 3 / k ∈ Clave A 08 sen6xcos3x cos3x = 0 ⇒ sen6x = 0 si cos3x ≠ 0 cos3x ≠ 0 ⇒ x = p 6 , p 2 , 5p 6 , 7p 6 , 9p 2 , 11p 6 cos6x = 0 ⇒ Vp = p 2 6x = 2pk ± p 2 ⇒ x = p 3 k ± p 12 ∴ ∃ 11 soluciones Clave B 09 sen42x + cos42x – sen22x = 1 ⇒ 1 - 2sen22xcos22x – sen22x = 1 ⇒ sen22x (–1–2cos22x) = 0 ⇒ sen22x (2 + cos4x) = 0 ⇒ sen2x = 0 ⇒ x = np 2 ⇒ C.S. = np 2 /n ∈ Clave A 10 1 – tg2x 1 + tg2x = 1 – cos4x 1 + sen4x cos2x – sen2x cos2x + sen2x = 1 – cos4x (sen2x + cos2x)2 cos4x = 1 – cos4x 4x = 2np ± p 3 C.S. = np 2 ± p 12 /n ∈ Clave C 11 4sen2x cos2x – 8sen2x = 6 ⇒ 4sen2x – 8sen2xcos2x = 6cos2x ⇒ 2(1 –cos2x) - 2sen22x = 3(1 + cos2x) ⇒ 2sen22x + 5cos2x + 1 = 0 ⇒ (cos2x – 3)(2cos2x + 1) = 0 ⇒ cos2x = – 1 2 ⇒ x = – p 3 = a Catetos: 10cosa= 5 ∧ –8 3sena = 12 ⇒ El perímetro es 30 cm. Clave B 12 tan(x + 45°) + tan(x – 45°) – 2cotx = 0 cot(45° – x) – tan(45° – x) – 2cotx = 0 2 . cot(2(45° – x)) – 2cotx = 0 cot(90° – 2x) = cotx tan2x = cotx De acuerdo a la nota del problema ante- rior se tendrá que: 3x = (2k + 1) p 2 / k ∈ x = (2k + 1) p 6 / k ∈ Clave B 13 I. x – y = 53° 2 II. coty – cotx = 2 En (II) sen(x – y) senx · seny = 2 sen(x – y) = 2senx · seny sen(x – y) = cos(x – y) – cos(x + y) Reemplazamos en (I) sen 53° 2 = cos 53° 2 – cos(x + y) 1 5 = 2 5 – cos(x + y) cos(x + y) = 1 5 ⇒ x + y = 127° 2 Clave A 14 cos2x ≠ 0 ⇒ 2x ≠ p 2 ; 3p 2 ⇒ x ± p 4 ; 3p 4 sen6x + sen2x cos2x = 0 ⇒ 2sen4xcos2x cos2x = 0 ⇒ sen4x = 0 ⇒ 4x = 0; p; 2p; 3p; 4p ⇒ x = 0, p 4 , p 2 , 3p 4 ; p ⇒ 3 soluciones Clave C 15 sen4x senx – sen6x sen3x = 2 . senx 4 . senx . cosx . cos2x senx – 2 . sen3x . cos3x sen3x = 2 . senx 4.cosx.cos2x – 2 . cos3x = 2 . senx 2.cosx.cos2x – cos3x = 2 2 senx (cos3x + cosx) - cos3x = 2 2 senx cosx = 2 2 senx → tanx = 2 Las soluciones pertenecientes al intervalo de 〈0; 2p〉 son: ∴ |x2 – x1| = p Clave B ACTIVIDADES CAP 28 RESOLUCIÓN DE TRIÁNGULOS OBLICUÁNGULOS 01 q 2 q 2 2 2 3 n n n A H B D C 30° a 2sen q 2 – 3sena = 2 n 2 – 3 n 3 ∴ 2sen q 2 – sena = 0 Clave A x ∈ IC : x1 = arc tan( 2) x ∈ IIIC : x2 = p + arc tan( 2) EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 54 02 El triángulo mostrado es un : 60° xL L 2xL 60° n 3 n 2n ⇒ L = xL 3 ∴ x = 3 3 Clave D 03 H C A l h 3l 2a 2q B E = sen2a · tan(a – q) sen2q · tan(a + q) E = h l h 3l × 3l – l 3l + l = 1 1 1 3 × 2 4 ∴ E = 3 2 Clave D 04 60° C H B H x ax ax ax 330°120° x2 = (2ax)2 + (ax 3)2 ⇒ 1 = 4a2 + 3a2 ⇒ a2 = 1 7 ∴ a = 7 7 Clave B 05 2n 3 2n 3 n 13 4n 4n 2n 2n 2n n n A B N T C D DTM: (n 13)2 = (n 3)2 + (2n 3) – 2n 3(2n 3)cosq ⇒ cos = 1 6 ∴ q = arccos 1 6 Clave C 06 5tana = 5 3 tana = 3 ⇒ a = 60° A 12 9 a C B x x2 = 122 + 92 – 2(9)(12)cos60° ⇒ x = 3 13 ≅ 11 Luego: 12 + 9 + 11 3 = 10 + 2 3 Por lo tanto, son necesarias 11 estacas para cercar el terreno. Clave D 07 Por lo expuesto anteriormente Se concluye que: γ = 2a 42 = 52 +62 – 2(5)(6)cosa C A B6 4 5 γ 2a a ⇒ cosa = 3 4 sen(a + γ) senγ = sen3a sen2a = sena(2cos2a + 1) sena sen(a + γ) senγ = 2(2cos2a – 1) + 1 2cosa = 4cos2a – 1 2cosa ∴ sen(a + γ) senγ = 4 3 4 2 – 1 2 3 4 = 5 6 Clave A 08 21sena = 21 5 2 3 21 ∴ 21sena = 5 2 3 B A A 60° N 5 C 3 2 5 2 5 3/2 21 Clave C 09 B 4 C A 2 3 senB 2 = 9 2 – 4 2 9 2 – 8 2 2(4) = 10 8 ⇒ tanB 2 = 15 9 senA 2 = 9 2 – 4 2 9 2 – 6 2 2(3) = 10 4 ⇒ tanA 2 = 15 3 ⇒ tan A – B 2 = 15 3 – 15 9 1 + 15 3 × 15 9 ⇒ tan A – B 2 = 15 7 Clave E 10 b2 + c2 – a2 2abc + a 2 + c2 – b2 2abc + a 2 + b2 – c2 2abc = a 2 + b2 + c2 R3 ⇒ 2abc = R3 ... (I) Se sabe: senA = a 2R ; senB = b 2R ; senC = c 2R ⇒ senAsenBsenC = abc 8R3 ... (II) (I) en (II): senAsenBsenC = abc 8(2abc) ∴ senAsenBsenC = 1 16 Clave D CUADERNO DE TRABAJO 01 Aplicando ley de senos: 10 sena = sen2a 10 3 1 sena = 2sena cosa 3 cosa = 3 2 a = 30° En el triángulo: 30° + 60° + x = 180° x = 90° Clave C 02 Por ley de cosenos: 52 = (8)2 + (6)2 – 2(8)(6)cosA 96cosA = 75 cosA = 75 96 secA = 96 75 A B 6 5 8 C Luego: 25secA = 25 96 75 = 32 Clave B 03 Ley de senos: a – 1 sena = a + 1 sen2a a – 1 a + 1 a (Lado mayor) (Lado menor) a – 1 sena = a + 1 2sena cosa 2cosa = a + 1 a – 1 (Lado menor) (Lado mayor) Clave A 04 Ley de cosenos: x2 = (x + 1)2 + (x – 2)2 – 2(x + 1)(x – 2)1 2 x = 7 Perímetro = 3x – 1 = 3(7) – 1 = 20 Clave D 05 Del dato: a b + c = c b – a – 1 = c + a – b b – a ab – a2 = bc + ab – b2 + c2 + ac – bc b2 = a2 + c2 + ac ...dando forma de ley de cosenos b2 = a2 + c2 + 2ac 1 2 – cosb b = 120° Piden: 3(cotb – tanb) = 3 – 3 1 – (– 3) = –1 + 3 = 2 Clave D 06 Por ley de senos: b = 2RsenB 32 = 2R(0,8) = 2R 8 10 R = 20 cm 32 = b R R A COB Clave C 07 Como A + B + C = 180° senA = sen(180° – (B + C)) senA = sen(B + C) Ley de cosenos: ( 28)2 = 42 + 36 – 2(6)(4)cosA cosA = 16 + 36 – 28 2(6)(4) = 24 48 = 1 2 A = 60° Piden: sen(B + C) = senA = 3 2 Clave A 2ax n 3 EDITORIAL INGENIOSOLUCIONARIO - TRIGONOMETRÍA 5° 55 08 Ley de senos: a + 1 sen2a = a – 1 sena ; A B C a – 1 a + 1 a cosa = a + 1 2(a – 1) ...(1) Ley de cosenos: (a – 1)2 = (a + 1)2 + a2 – 2(a + 1)acosa ...(2) Reemplazando (1) en (2): a2 – 5a = 0 a = 5 Suma de lados: 3a = 15 Clave C 09 Aplicando ley de tangente, b = 3 c = 2 B + C 2 tan B – C 2 tan = b + c b – c tan(60°) B – C 2 tan = 5 1 tan B – C 2 = 3 5 B – C 2 28 5 3 Piden: 28cos2 B – C 2 = 28× 28 5 2 28×25 28 = 25 Clave A 10 ACB (Isósceles) Sea AB = 2 BC = sec80° BPC (Ley de senos) 2 senx = sen80° sen(160° – x) 2 senx = sen80° sen(20° + x) 2sen(160° – x) = senx sec80° 2sen(20° + x) = sena cos80° 2sen(20° + x)cos80° = senx sen(100° + x) – sen(60° – x) = senx sen(80° – x) = senx + sen(60°– x) sen(80° – x) = 2sen30° cos(30° – x) sen(80° – x) = cos(30° – x) 80° – x + 30° – x = 90° x = 10° Piden: sen3x = sen30° = 1 2 Clave B TAREA 01 x sen45° = 3 2 sen30° ⇒ x = 6 02 a senA = b senB = c senC = 2R ⇒ senA = a 2R ADC: 8 senA = b sen90° ⇒ 8 = bsenA ⇒ 8 = b a 2R ⇒ R = ab 8 A C x 105° 30° B 3 2 03 (I) Ley de senos: 3 + 1 senβ = 1 sen15° ⇒ senβ = 2 2 ⇒ β = 45° (II) a = 120° y tga = – 3 04 (I) Ley de senos: sena senq = 3 2 (II) Ley de tangentes: tg a + q 2 tg a – q 2 = 5 De (I) y (II): senq sena . tg a + q 2 tg a – q 2 = 2 3 (5) = 10 3 REFORZANDO 01 m n = ? Del gráfico por el teorema de senos m n = sen2a sena → m n = 2.sena.cosa sena ∴ m n = 2cosa Clave B 02 Por teorema de Pitágoras: d2 = 92 + 402 = 41 Clave C 03 asenB = bsenA Ley de senos: asenC = csenA A D C b a 8 8 B CA B 1cm 15° a β ( 3 + 1)cm A C 2k 3k a q B A C n m 2a a B S N O E 20° 70° 40 d Barco 1 9Barco 2 E = asenB + bsenA asenC + csenA = bsenA + bsenA csenA + csenA E = 2bsenA 2csenA = 3c c = 3 Clave A 04 mBAPB = ? Del gráfico se tiene que x = 5q Pero 8q = 90° → q = 11°15' Reemplazamos en x: x = 5x(11°15') ∴ x = 56°15' Clave D 05 Por ley de senos: d sen135° = b sen15° ⇒ d = sen45° sen15° ⇒ d = 2 2 6 – 2 4 2 ⇒ d = 2 2( 6 + 2) 4 2 ⇒ d = 3 + 1 Clave C 06 a2 = b2 + c2 – 2bccosA Ley de cosenos: b2 = a2 + c2 – 2accosB ⇒ k = –(2bccosA) senA cosA + (2accosB) senB cosB k = –2c[bsenA – asenB] = –2c(0) = 0 ⇒ k + 1 = 1 Clave D 07 E = senA – senB senA + senB + b – a b + a ⇒ E = ⇒ E = tgA – B 2 ctgA + B 2 – tgA – B 2 ctgA + B 2 ⇒ E = 0 Clave C P E O AB Persona (B) Persona (A) 4q x N O N 1/ 4N E 4q 3q 4qq Oeste Este1km A d B 45°30° 15° + sen A – B 2 tg A – B 2 cos A – B 2 tg A + B 2 2cos A + B 2 2sen A + B 2 EDITORIAL INGENIO SOLUCIONARIO - TRIGONOMETRÍA 5° 56 08 Ley de senos: a = ksenA b = ksenB c = ksenC E = acosA + bcosB 2cosAcosB + cosC E = k(2senAcosA + 2senBcosB) 2(2cosAcosB + cosC) E = k(sen2A + sen2B) 2[cos(A + B) + cos(A – B) + cosC] E = 2ksen(A + B)cos(A – B) 2cos(A – B) = ksenC = c Clave E 09 E = a3 . c2(acosC – ccos(B + C))sen2B . senC = a3 . c2(acosC + ccosA)sen2B . senC = a3 . c2 . b . sen2B . senC = a3(c2 . sen2B) (b . senC) = a3(c2 . sen2B) (c . senB) = a3 . c3 . sen3B = 8 acsenB 2 3 = 8 . ( 73 )3 = 56 Clave C 10 H = ? Del gráfico: Hcot30° = 10 3cos15° H 3 = 10 3 32 + 2 ∴ H = 5 32 + Clave B 15° E H aO S 10 3 30° Diana Alejandro 11 3 cot2a = ? cota = n 2 n 3 ⇒ cota = 2 3 ⇒ 3cot2a = 2 Clave B 12 A + B + C = 180° ⇒ C = 30° a senA = b senB = c sen30° = 2c ⇒ a = 2csenA b = 2csenB a2 = 4c2sen2A ⇒ b2 = 4c2sen2B ⇒ a2 + b2 = 4c2[2sen2A + 2sen2B] = 2c2[2 – (cos2A + cos2B)] 4c2(cos2A + cos2B) = 4c2 – a2 – b2 Clave C 13 Ley de cosenos: c2 = a2 + b2 – 2abcosC ⇒ 0 = a2 + b2 – (a2 + b2 – 2abcosC) + 1 2 ab ⇒ cosC = – 1 4 ctg2 C 2 = 1 +cosC 1 – cosC = 1 – 1 4 1 – – 1 4 = 3 4 5 4 = 3 5 Clave B a n 2 n 3 n 60° Posición (1) Posición (2) Poste 14 d = ? d A B T 75m S O 30° 60° Torre • AT = 25 3 • BT = 75 3 d = (25 3)2 + (75 3)2 ⇒ d = 25 30 Clave A 15 tana cotβ = ? Del gráfico se tiene que tana = 4h n y cotβ = n 6h Multiplicamos: tana cotβ = 4h n n 6h ∴ tana cotβ = 2 3 Clave B h h h h h a a β β h n n