Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Trigonometry

Question:

What will be the value of cosx cosecx - sinx secx

Options:

cot\(\frac{2x}{2}\)

sin\(\frac{x}{2}\)

2cot2x

sec\(\frac{2x}{3}\)

Correct Answer:

2cot2x

Explanation:

cosx cosecx - sinx secx 

= \(\frac{cosx}{sinx}\)-\(\frac{sinx}{cosx}\)   

= \(\frac{(cos^2x-sin^2x)}{sinx cosx}\)

Multiply and divide by 2

\(\frac{2(cos^2x-sin^2x)}{2(sinx cosx)}\) = \(\frac{2cos2x}{sin2x}\)          [cos2x= cos2x - sin2x, sin2x = 2sinx cosx]

= 2cot2x