Tiêu đề TRIGONOMETRIC FUNCTIONS Q-7.pdf ✅

Class : XIth Subject : MATHS Date : DPP No. : 7 1. The number of solutions for the equation sin 2x + cos 4x = 2 is a) 0 b)1 c) 2 d)∞ 2. If sin θ1 + sin θ2 + sin θ3 = 3, then cos θ1 + cos θ2 + cos θ3 = a) 3 b)2 c) 1 d)0 3. The equation ksin x + cos 2 x = 2 k ― 7 possesses solution, if a) k > 6 b)2 ≤ k ≤ 6 c) k > 2 d)None of these 4. Ifcos 2B = cos(A + C) cos(A ― C) , then tanA,tanB,tan C are in a) AP b)GP c) HP d)None of these 5. If n is an odd positive integer, then ( cosA + cosB sinA ― sinB ) n + ( sinA + sinB cosA ― cosB ) n = a) ―1 b)1 c) 0 d)None of these 6. If α,β are the solutions of atan θ + b sec θ = c, then tan(α + β) = a) 2 ac a 2 ― c 2 b) 2 ac c 2 ― a 2 c) 2 ac a 2 + c 2 d) ac a 2 + c 2 7. If tan θ + tan (θ + π 3 ) + tan (θ + 2π 3 ) = 3, then which of the following is equal to 1? a)tan 2θ b)tan 3θ c) tan2 θ d)tan3 θ 8. If y = 1 + 4sin2 x cos2 x, then a) 1 ≤ y ≤ 2 b) ―1 ≤ y ≤ 1 c) ―3 ≤ y ≤ 3 d)None of these 9. If α + β ― γ = π, then sin2α + sin2β ― sin2 γ is equal to a) 2sinα sinβ cos γ b)2cosαcosβcos γ c) 2sinαsinβsin γ d)None of the above 10. In a ∆ABC, cot A 2 + cot B 2 + cot C 2 cotA + cotB + cot C = a) (a + b + c) 2 a 2 + b 2 + c 2 b) a 2 + b 2 + c 2 (a + b + c) 2 c) s d)∆ 11. The expression tan2α + cot2α is a) ≥ 2 b) ≤ 2 c) ≥ ―2 d)None of these 12. For m ≠ n, if tan m θ = tan n θ, the different values of θ are in a) A.P. b)H.P. c) G.P. d)No particular sequence 13. If in a triangle ABC, sinA :sin C = sin(A ― B) :sin(B ― C) then, a 2 :b 2 :c 2 are in Topic :- TRIGONOMETRIC FUNCTIONS