Trigonometry (Railway Maths) (Part – V)

Total Questions: 50

1. If 5sinθ + 12cosθ = 13, then find the value of 5 cosθ - 12 sin θ? [RRB NTPC 03/03/2021 (Morning) ]

Correct Answer: (c) 0
Solution:

2. If θ = 60°, then the value of 2 cot²θ / 1 - cot²θ = ? [RRB NTPC 04/03/2021 (Evening) ]

Correct Answer: (d) 1
Solution:

3. If A lies in the second quadrant and 13 sinA − 12 = 0, then 5 sinA + 12 cosA + tan²A − (sec²A − 1) = ? [RRB NTPC 05/03/2021 (Morning)]

Correct Answer: (c) 0
Solution:

4. The value of [RRB NTPC 05/03/2021 (Morning)]

Correct Answer: (b) 1/2
Solution:

5. Find the value of sin(5π/3). [RRB NTPC 07/03/2021 (Morning)]

Correct Answer: (c) −√3/2
Solution:

6. In triangle ABC, lengths of sides opposite respective angles are a = 25, b = 45, c = 30, then the value of cosA is: [RRB NTPC 07/03/2021 (Evening)]

Correct Answer: (b) 23/27
Solution:

7. ABC is a right-angled triangle, right angled at C. If A = 60° and AC = 20√3 units, then find AB. [RRB NTPC 08/03/2021 (Morning)]

Correct Answer: (a) 40√3 units
Solution:

8. If sinθ + cosθ = √3 cos(90° − θ), then tanθ = ? [RRB NTPC 08/03/2021 (Evening)]

Correct Answer: (b) 1 / (√3 − 1)
Solution:

9. Find the value of sec(2100°). [RRB NTPC 09/03/2021 (Morning)]

Correct Answer: (c) 2
Solution:

sec(2100)°
= sec(360 × 5 + 300)° = sec(300)°
= sec(360 − 60)° = sec(60)° = 2

10. Find the value of cos100° cos40° + sin100° sin40°. [RRB NTPC 09/03/2021 (Morning)]

Correct Answer: (d) 1/2
Solution:

cos100° cos40° + sin100° sin40°
(cos(A − B) = cosA cosB + sinA sinB)
= cos(100° − 40°)
= cos60° = 1/2