Trigonometry (Railway Maths) (Part – V)

Total Questions: 50

41. What is the value of tan(15°)? [RRB NTPC 24/07/2021 (Morning)]

Correct Answer: (a) 2 - √3
Solution:

tan(15°) = 2 - √3

42. The value of tan75° - cot75° is equal to: [RRB NTPC 24/07/2021 (Evening)]

Correct Answer: (c) 2√3
Solution:

tan 75° - cot 75°
= (2 + √3) - (2 - √3) = 2√3

43. Find the value of cos1°cos2°cos3°........cos89°cos90°. [RRB NTPC 26/07/2021 (Morning)]

Correct Answer: (c) 0
Solution:

As we know:
cos 90° = 0
Then the value of the following:
cos 1° × cos 2° × cos 3° × … × cos 89° × cos 90° = 0

44. If tanθ = -4/3, then sinθ is: [RRB NTPC 26/07/2021 (Evening)]

Correct Answer: (b) -4/5 or 5/4
Solution:

tan θ = -4/3 = p/b, h = 5
Now, sin θ = 4/5 or -4/5

45. The value of tan1° tan2° tan3° tan89° / tan is equal to: [RRB NTPC 31/07/2021 (Morning)]

Correct Answer: (c) 1
Solution:

46. If tanθ = √3 + 1 / 2, then the value of 2√3cotθ + 1 is: [RRB NTPC 31/07/2021 (Evening) ]

Correct Answer: (a)
Solution:

47. Find the value of sin(7π/4) × sin(π/4) × sin(3π/4) × sin(5π/4). [RRB JE 22/05/2019 (Afternoon)]

Correct Answer: (a) 1/4
Solution:

48. If 0° < θ ≤ 90°, solve for 'θ' where cos²θ - 3cosθ + 2 = 2sin²θ. [RRB JE 22/05/2019 (Afternoon)]

Correct Answer: (d) 90°
Solution:

49. Find the value of sin120° × sin240° × sin270°. [RRB JE 22/05/2019 (Afternoon)]

Correct Answer: (c) 3/4
Solution:

50. Simplify: tan(60° - θ) - cot(30° + θ) [RRB JE 22/05/2019 (Evening)]

Correct Answer: (c) 0
Solution: