Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Trigonometry

Question:

If sinθ + cosec θ = 5 , find the value of sin2θ + cosec2θ .

Options:

30

27

23

25

Correct Answer:

23

Explanation:

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

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

sinθ + \(\frac{1}{sinθ}\) = 5

⇒ sin2θ + \(\frac{1}{sin^2θ}\) = (5)2 - 2

⇒ sin2θ + cosec2θ = 25 - 2 = 23