Tiêu đề TRIGONOMETRIC FUNCTIONS Q-8.pdf ✅

Class : XIth Subject : MATHS Date : DPP No. : 8 1. In a ∆ABC, if A = 45°,b = 6,a = 2, then B = a) 30° or 150° b)60° or 120° c) 45° or 135° d)None of these 2. Two sides of a triangle are 2 2 cm and 2 3 cm and the angle opposite to the shorter side of the two is π 4 . The largest possible length of the third side is a) ( 6 + 2) cm b)(6 + 2) cm c) ( 6 ― 2) cm d)None of these 3. The total number of ordered pairs (r,θ) satisfying rsin θ = 3,r = 4(1 + sin θ ), where r > 0 and θ ∈ [ ― π,π] is a) 0 b)2 c) 4 d)None of these 4. sin 65° + sin 43° ― sin 29° ― sin 7° is equal to a) cos 36° b)cos 18° c) cos 9° d)None of these 5. If sinB = 1 5 sin(2A + B), then tan(A + B) tanA is equal to a) 5/3 b)2/3 c) 3/2 d)3/5 6. If A + B + C = π andcosA = cosB cos C, then tanB tan C is equal to a) 1 2 b)2 c) 1 d) ― 1 2 7. If sin x + cosec x = 2 then, sinn x + cosec n x is equal to a) 2 b)2 n c) 2 n―1 d)2 n―2 8. If in a triangle ABC,a 2 ― b 2 a 2 + b 2 = sin(A ― B) sin(A + B), then the triangle is a) Right angled or isosceles b)Right angled and isosceles c) Equilateral d)None of these 9. In a ∆ABC,cosA = cosB cos C, then cotB cot C is equal to a) 2 b)3 c) 1/2 d)5 10. In a ∆ABC if a = 13,b = 14 and c = 15, then reciprocals of r1,r2 and r3 are in the ratio a) 6 :7 :8 b)6 :8 :7 c) 8 :7 :6 d)None of these 11. sin 7θ + 6 sin 5θ + 17 sin 3θ + 12 sin θ sin 6θ + 5 sin 4θ + 12 sin 2θ is equal to a) 2cos θ b)cos θ c) 2sin θ d)sin θ 12. In a triangle the angles are in A.P. and the lengths of the two larger sides are 10 and 9 respectively, then the length of the third side can be a) 5 ± 6 b)0.7 c) 5 +6 d)None of these 13. The general value of x for which cos 2x, 1 2 and sin 2x are in AP, are given by Topic :- TRIGONOMETRIC FUNCTIONS