Content text 6. Trigonometric Ratios CQ & MCQ Practice Sheet Solution [HSC 26].pdf
w·KvYwgwZK AbycvZ CQ & MCQ Practice Sheet Solution (HSC 26) 1 06 w·KvYwgwZK AbycvZ Trigonometric Ratios WRITTEN 1| O B A C e ̈vmva© OC = 6.5 cm I BC = 5 cm [iv. †ev. 19] (K) tanx = 3 4 , cosx abvZ¥K n‡j, sinx Gi gvb wbY©q Ki| (L) DÏxc‡Ki ABC Gi †ÿ‡Î cÖgvY Ki †h, sin2A – sin2B + sin2C = 0 (M) DÏxc‡Ki Qvqv‡Niv As‡ki †ÿÎdj wbY©q Ki| mgvavb: (K) †`Iqv Av‡Q, tanx = 3 4 , cosx abvZ¥K A_©vr, x †KvYwU cÖ_g PZzf©v‡M Aew ̄’Z| j¤^ I f~wg h_vμ‡g 3 I 4 GKK| AwZfzR = 3 2 + 42 = 5 sinx = 3 5 (Ans.) 4 5 3 (L) wPÎ Abymv‡i, B = 90 [ Aa©e„Ë ̄’ †KvY] A = 90 – C evgcÿ = sin2A – sin2B + sin2C = sin2 (90 – C) – sin2 90 + sin2C = cos2C – 1 2 + sin2C = cos2C + sin2C – 1 = 1 – 1 = 0 = Wvbcÿ sin2A – sin2B + sin2C = 0 (Proved) (M) †`Iqv Av‡Q, e„ËwUi e ̈vmva© OC = 6.5 cm AC = 2 6.5 cm = 13 cm Ges BC = 5 cm †h‡nZz ABC mg‡KvYx wÎfzR Ges B = 1 mg‡KvY| AC2 = BC2 + AB2 AB = AC2 – BC2 = 132 – 5 2 cm = 12 cm ABC wÎfz‡Ri †ÿÎdj = 1 2 BC AB = 1 2 5 12 = 30 cm2 Avevi, ABC Aa©e„‡Ëi †ÿÎdj = 1 2 3.1416 (6.5)2 cm2 = 66.366 cm2 Qvqv‡Niv As‡ki †ÿÎdj = (66.366 – 30) cm2 = 36.37 cm2 (Ans.) 2| `„k ̈Kí-1: f(x) = sinx `„k ̈Kí-2: OABC GKwU i¤^m Ges OAC e„ËKjv O †Kw›`aK e„‡Ëi Ask| C A B O 40 cm 45 [w`. †ev. 19] (K) cosecx + 16 sinx = 8 n‡j, cÖgvY Ki †h, sinn x + cosecn x = 22n + 2–2n (L) `„k ̈Kí-2 n‡Z ABCA As‡ki †ÿÎdj wbY©q Ki| (M) `„k ̈Kí-1 n‡Z y = f 2 – 2x ; – x Gi †jLwPÎ A1⁄4b Ki| mgvavb: (K) †`Iqv Av‡Q, sinx + 16cosecx = 8 sinx + 16 sinx = 8 sin2 x + 16 = 8sinx sin2 x – 2.4.sinx + 42 = 0 (sinx – 4)2 = 0 sinx = 4 GLb sinn x + cosecn x = sinn x + 1 sinn x = 4n + 1 4 n = 22n + 2–2n (Proved) (L) C A B O 40 cm 45
w·KvYwgwZK AbycvZ CQ & MCQ Practice Sheet Solution (HSC 26) 3 •ewkó ̈: (i) †jLwPÎwU Aew”Qbœ eμ‡iLv Ges AvK...wZ †XD Gi g‡Zv| (ii) †jLwPÎwU g~jwe›`yMvgx| (iii) sin2x Gi m‡e©v”P gvb 1 Ges me©wb¤œ gvb – 1 4| `„k ̈Kí-1: `„k ̈Kí-2: = 58 O B A f(x) = cotx [e. †ev. 19] (K) cos2A = 1 – cos4A n‡j, †`LvI †h, cot4A – cot2A = 1 (L) `„k ̈Kí-1 G cÖ`wk©Z e„‡Ëi cwiwa 31.416 †m.wg. n‡j e„ËwUi Qvqv‡Niv As‡ki †ÿÎdj wbY©q Ki| (M) `„k ̈Kí-2 n‡Z f 2 – x = y Gi †jLwPÎ AvuK, hLb – 2 < x < 2 mgvavb: (K) †`Iqv Av‡Q, cos2A = 1 – cos4A cos4A = 1 – cos2A cos3A = sin2A cot4A = 1 sin2A [sin4A Øviv fvM K‡i] cot4A = cosec2A cot4A = 1 + cot2A [cosec2A – cot2A = 1] cot4A – cot2A = 1 (Showed) (L) †`Iqv Av‡Q, e„‡Ëi cwiwa = 31.416 †m.wg. e„‡Ëi e ̈vmva© r n‡j, 2r = 31.416 r = 31.416 2 †m.wg. = 5 †m.wg. GLb AOB e„ËKjvi †ÿÎdj = 360 r 2 = 58 360 r 2 Ges m¤ú~Y© e„‡Ëi †ÿÎdj = r 2 e„ËwUi Qvqv‡Niv As‡ki †ÿÎdj = r 2 – 360 r 2 eM© †m.wg. = r 2 1 – 360 eM© †m.wg. = 3.1416 5 2 1 – 58 360 eM© †m.wg. = 3.1416 25 360 – 58 360 eM© †m.wg. = 3.1416 25 151 180 eM© †m.wg. = 65.886 eM© †m.wg. (Ans.) (M) †`Iqv Av‡Q, f(x) = cotx y = f 2 – x = cot 2 – x = tanx y = tanx; – 2 < x < 2 x Gi wewfbœ gv‡bi Rb ̈ y = tanx Gi gvb `yB `kwgK ̄’vb ch©šÍ wbY©q Kwi: x – 2 – 7 18 – 3 – 4 – 6 0 6 4 y – – 2.75 – 1.73 – 1 – 0.58 0 0.58 1 x 3 7 18 2 y 1.73 2.75 x Aÿ eivei ÿz`aZg e‡M©i 3 evû = 6 Ges y Aÿ eivei ÿz`aZg e‡M©i 3 evû = 1 GKK a‡i †jLwPÎwU A1⁄4b Kwi| Y Y X X O 2 – 2 5| `„k ̈Kí-1: f() = 1 + cos2 cos `„k ̈Kí-2: g(x) = cosx [iv., Kz., P., e. †ev. 18] (K) sin2 – cos = 0 n‡j cÖgvY Ki †h, tan4 – sec2 = 0 (L) `„k ̈Kí-1 G f() = 5 2 n‡j †`LvI †h, cosn + secn = 2n + 2–n (M) – 2 x 2 e ̈ewa‡Z g(3x) Gi †jLwPÎ A1⁄4b Ki| mgvavb: (K) sin2 – cos = 0 sin2 = cos sin4 = cos2 sin4 cos4 = 1 cos2 tan4 = sec2 tan4 – sec2 = 0 (Proved) (L) †`Iqv Av‡Q, f() = 5 2 1 + cos2 cos = 5 2 2cos2 + 2 = 5cos 2cos2 – 5cos + 2 = 0 2cos2 – 4cos – cos + 2 = 0 (cos – 2)(2cos – 1) = 0 cos – 2 = 0 cos = 2 (MÖnY‡hvM ̈ b‡n) A_ev, 2cos – 1 = 0 cos = 1 2 sec = 2 cosn + secn = 1 2 n + 2n = 2n + 2–n (Showed)
4 Higher Math 1st Paper Chapter-6 (M) †`Iqv Av‡Q, g(x) = cosx g(3x) = cos3x awi, y = cos3x; – 2 x 2 x Gi wewfbœ gv‡bi Rb ̈ y = cos3x Gi gvb `yB `kwgK ̄’vb ch©šÍ ewm‡q cvB, x 0 18 9 6 2 9 5 18 3 7 18 y 1 0.87 0.5 0 – 0.5 – 0.87 – 1 – 0.87 x 4 9 2 y – 0.5 0 † ̄‹j wba©viY: x Aÿ eivei ÿz`aZg e‡M©i 2 evû = 18 y Aÿ eivei ÿz`aZg e‡M©i 10 evû = 1 1 0.5 0 – 0.5 – 1 0 18 6 5 18 X X Y Y O 2 7 18 – 2 – 7 18 – 5 18 – 18 – 6 •ewkó ̈: (i) †jLwPÎwU g~jwe›`yMvgx bq (ii) †jLwPÎwU Aew”Qbœ †XD AvK...wZi (iii) †jLwPÎ †_‡K †`Lv hvq †h, cos3x Gi m‡e©v”P gvb 1 Ges me©wb¤œ gvb – 1 6| A B C D 42 6cm 6cm (K) e„ËKjv ABC Gi †ÿÎdj wbY©q Ki| [Xv. †ev. 17] (L) ABDC Gi cwimxgv wbY©q Ki| (M) Qvqv‡Niv As‡ki †ÿÎdj wbY©q Ki| mgvavb: (K) GLv‡b, r = 6 cm, = 42 = 42 180 e„ËKjv ABC Gi †ÿÎdj = 1 2 6 2 42 180 = 21 5 = 13.19 sq.cm (Ans.) (L) e„Ëvsk BC Gi •`N© ̈ = 6 42 180 = 7 5 cm ABDC Gi cwimxgv = 6 + 6 + 7 5 = 16.4 cm (Ans.) (M) e„‡Ëi e„ËKjvi †ÿÎdj = 6 2 = 36 eM© †m.wg. ABC wÎfz‡Ri †ÿÎdj = 1 2 6 6 sin42 = 12.04 eM© †m.wg. (cÖvq) Qvqv‡Niv As‡ki †ÿÎdj = 36 – 12.04 = 101.06 eM© †m.wg. (cÖvq) (Ans.) 7| wP‡Î, ABCD GKwU AvqZ‡ÿÎ Ges ADE GKwU e„ËKjv| B 12m C A D E 60 13m 8m F (K) DE e„ËPv‡ci •`N© ̈ wbY©q Ki| (L) AEDF mxgve× GjvKvi †ÿÎdj wbY©q Ki| (M) DE AF AbycvZwU †Kv‡Yi †h w·KvYwgwZK AbycvZ wb‡`©k K‡i Zvi †jLwPÎ A1⁄4b Ki; †hLv‡b – mgvavb: (K) GLv‡b, r = AE = AD = BC = 12m 1 = 60 = 3 DE e„ËPv‡ci •`N© ̈ = r1 = 12 3 = 4 m (Ans.) (L) GLv‡b, DF = AF2 – AD2 = 132 – 122 = 5m AEDF mxgve× GjvKvi †ÿÎdj = AED e„ËKjvi †ÿÎdj + ADF wÎfz‡Ri †ÿÎdj = 1 2 122 60 180 + 1 2 12 5 = 105.4 eM© GKK (Ans.) (M) DÏxc‡Ki wP‡Î, DF AF = sin awi, y = sin; – ≤ ≤ Gi wewfbœ gv‡bi Rb ̈ y = sin Gi gvb `yB `kwgK ̄’vb ch©šÍ wbY©q Kwi| 0 12 6 4 3 5 12 2 7 12 y 0 0.26 0.5 0.71 0.87 – 0.96 1 0.96 2 3 3 4 5 6 11 6 y 0.87 0.71 0.5 0.26 0