Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Trigonometry

Question:

If sinθ + cosec θ = 4 , find the value of sin3θ + cosec3θ .

Options:

48

62

52

58

Correct Answer:

52

Explanation:

Formula I → [ cosec = \(\frac{1}{sinθ}\)]

Formula II → [If x + \(\frac{1}{x}\) = n and x3 + \(\frac{1}{x^3}\) = n3 - 3n]

sinθ + \(\frac{1}{sinθ}\) = 4

⇒ sin3θ + \(\frac{1}{sin^3θ}\) = (4)3 - 3 × 4

⇒ sin3θ + cosec3θ = 64 - 12 = 52