Class 11th Maths – RD Sharma Chapter 5 : trigonometric Functions Multiple Choice Questions (MCQs Solutions

  Mark the correct alternative in each of the following:

  1. If tan x = x − 1/4x , then sec x − tan x is equal to
    (a) −2x , 1/2x
    (b) −1/2x , 2x
    (c) 2x
    (d) 2x , 1/2x  Watch Solution

  2. If sec x = x + 1/4x , then sec x + tan x =
    (a) x , 1/x
    (b) 2x , 1/2x
    (c) −2x , 1/2x
    (d) −1/x , x Watch Solution

  3. If π/2 < x < 3π/2 , then √((1 − sin x)/(1 + sin x)) is equal to
    (a) sec x − tan x
    (b) sec x + tan x
    (c) tan x − sec x
    (d) none of these Watch Solution

  4. If π < x < 2π , then √((1 + cos x)/(1 − cos x)) is equal to
    (a) cosec x + cot x
    (b) cosec x − cot x
    (c) − cosec x + cot x
    (d) − cosec x − cot x Watch Solution

  5. If 0 < x < π/2 , and if (y + 1)/(1 − y) = √((1 + sin x)/(1 − sin x)) , then y is equal to
    (a) cot x/2
    (b) tan x/2
    (c) cot x/2 + tan x/2
    (d) cot x/2 − tan x/2 Watch Solution

  6. If π/2 < x < π, then √((1 − sin x)/(1 + sin x)) + √((1 + sin x)/(1 − sin x)) is equal to
    (a) 2 sec x
    (b) −2 sec x
    (c) sec x
    (d) − sec x Watch Solution

  7. If x = r sin θ cos ϕ, y = r sin θ sin ϕ and z = r cos θ, then x² + y² + z² is independent of
    (a) θ, ϕ
    (b) r, θ
    (c) r, ϕ
    (d) r Watch Solution

  8. If tan x + sec x = √3, 0 < x < π, then x is equal to
    (a) 5π/6
    (b) 2π/3
    (c) π/6
    (d) π/3 Watch Solution

  9. If tan x = −1/√5 and x lies in the IV quadrant, then the value of cos x is
    (a) √5/√6
    (b) 2/√6
    (c) 1/2
    (d) 1/√6 Watch Solution

  10. If 3π/4 < α < π, then √(2 cot α + 1/sin² α) is equal to
    (a) 1 − cot α
    (b) 1 + cot α
    (c) −1 + cot α
    (d) −1 − cot α Watch Solution

  11. sin⁶ A + cos⁶ A + 3 sin² A cos² A =
    (a) 0
    (b) 1
    (c) 2
    (d) 3 Watch Solution

  12. If cosec x − cot x = 1/2 , 0 < x < π/2 , then cos x is equal to
    (a) 5/3
    (b) 3/5
    (c) −3/5
    (d) −5/3 Watch Solution

  13. If cosec x + cot x = 11/2 , then tan x =
    (a) 21/22
    (b) 15/16
    (c) 44/117
    (d) 117/44  Watch Solution

  14. sec² x = 4xy/(x + y)² is true if and only if
    (a) x + y ≠ 0
    (b) x = y, x ≠ 0
    (c) x = y
    (d) x ≠ 0, y ≠ 0 Watch Solution

  15. If x is an acute angle and tan x = 1/√7 , then the value of (cosec² x − sec² x)/(cosec² x + sec² x) is
    (a) 3/4
    (b) 1/2
    (c) 2
    (d) 5/4 Watch Solution

  16. The value of sin² 5° + sin² 10° + sin² 15° + … + sin² 85° + sin² 90° is
    (a) 7
    (b) 8
    (c) 9.5
    (d) 10 Watch Solution

  17. sin² π/18 + sin² 2π/9 + sin² 7π/18 + sin² 4π/9 =
    (a) 1
    (b) 4
    (c) 2
    (d) 0 Watch Solution

  18. If tan A + cot A = 4, then tan⁴ A + cot⁴ A is equal to
    (a) 110
    (b) 191
    (c) 80
    (d) 194 Watch Solution

  19. If x sin 45° cos² 60° = (tan² 60° cosec 30°)/(sec 45° cot² 30°) , then x =
    (a) 2
    (b) 4
    (c) 8
    (d) 16 Watch Solution

  20. If A lies in second quadrant and 3 tan A + 4 = 0, then the value of 2 cot A − 5 cos A + sin A is equal to
    (a) −53/10
    (b) 23/10
    (c) 37/10
    (d) 7/10 Watch Solution

  21. If cosec x + cot x = 11/2 , then tan x =
    (a) 21/22
    (b) 15/16
    (c) 44/117
    (d) 117/43 Watch Solution

  22. If tan θ + sec θ = eˣ, then cos θ equals
    (a) (eˣ + e⁻ˣ)/2
    (b) 2/(eˣ + e⁻ˣ)
    (c) (eˣ − e⁻ˣ)/2
    (d) (eˣ − e⁻ˣ)/(eˣ + e⁻ˣ) Watch Solution

  23. If sec x + tan x = k, cos x =
    (a) (k² + 1)/2k
    (b) 2k/(k² + 1)
    (c) k/(k² + 1)
    (d) k/(k² − 1) Watch Solution

  24. If f(x) = cos² x + sec² x, then
    (a) f(x) < 1
    (b) f(x) = 1
    (c) 1 < f(x) < 2
    (d) f(x) ≥ 2 Watch Solution

  25. Which of the following is incorrect?
    (a) sin x = −1/5
    (b) cos x = 1
    (c) sec x = 1/2
    (d) tan x = 20 Watch Solution

  26. The value of cos 1° cos 2° cos 3° … cos 179° is
    (a) 1/√2
    (b) 0
    (c) 1
    (d) −1 Watch Solution

  27. The value of tan 1° tan 2° tan 3° … tan 89° is
    (a) 0
    (b) 1
    (c) 1/2
    (d) not defined Watch Solution

  28. Which of the following is correct?
    (a) sin 1° > sin 1
    (b) sin 1° < sin 1
    (c) sin 1° = sin 1
    (d) sin 1° = π/180 sin 1 Watch Solution

  29. If tan θ = −4/3, then sin θ is equal to
    (a) −4/5 but not 4/5
    (b) −4/5 or 4/5
    (c) 4/5 but not −4/5
    (d) none of these Watch Solution

  30. If sin θ and cos θ are the roots of the equation ax² − bx + c = 0, then a, b and c satisfy the relation
    (a) a² + b² + 2ac = 0
    (b) a² − b² + 2ac = 0
    (c) a² + c² + 2ab = 0
    (d) a² − b² − 2ac = 0 Watch Solution

  31. If sin θ + cosec θ = 2, then sin² θ + cosec² θ is equal to
    (a) 1
    (b) 4
    (c) 2
    (d) none of these Watch Solution

  32. Which of the following is incorrect?
    (a) sin θ = −1/5
    (b) cos θ = 1
    (c) sec θ = 1/2
    (d) tan θ = 20 Watch Solution

  33. If for real values of x, cos θ = x + 1/x , then
    (a) θ is an acute angle
    (b) θ is a right angle
    (c) θ is an obtuse angle
    (d) No value of θ is possible Watch Solution

 

 

 

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