Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Trigonometry

Question:

\(\sqrt { \frac{1- cos θ}{1+cosθ} } × \sqrt { \frac{cosecθ - cosθ}{cosec θ+cot θ} } = \frac{1-r}{1+r}\), find the value of r.

Options:

sin θ

 cos θ

tan θ

cot θ

Correct Answer:

 cos θ

Explanation:

⇒ \(\sqrt { \frac{1- cos θ}{1+cosθ} } × \sqrt {\frac{\frac{1}{sinθ}-\frac{cosθ}{sinθ}}{\frac{1}{sinθ}+\frac{cosθ}{sinθ}}} = \frac{1-r}{1+r}\)

⇒ \(\sqrt { \frac{1- cos θ}{1+cosθ} } × \sqrt { \frac{1 - cosθ}{1+cos θ} } = \frac{1-r}{1+r}\)

⇒ \(\frac{1- cos θ}{1+cosθ} = \frac{1-r}{1+r}\)

r = cos θ