Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Trigonometry

Question:

If sinθ + cosec θ = 4 , find the value of sin2θ + cosec2θ.

Options:

15

18

16

14

Correct Answer:

14

Explanation:

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

Formula II → [If x + \(\frac{1}{x}\) = n and x2 + \(\frac{1}{x^2}\) = n2 - 2 ]

sinθ + \(\frac{1}{sinθ }\) = 4

⇒ sin2θ + \(\frac{1}{sin^2θ}\) = (4)2 - 2

⇒ sin2θ + cosec2θ = 16 - 2 = 14