Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Trigonometry

Question:

If $(1 + cot^2 θ) + ( 1 + (cot^2 θ)^{-1})$ is equal to k, then $\sqrt{k}$ = ?

Options:

sin θ sec θ

cosec θ cos θ

cosec θ sec θ

sin θ cos θ

Correct Answer:

cosec θ sec θ

Explanation:

( 1 + cot²θ ) + {1 + (cot²θ)-1}\)   = k

( 1 + cot²θ ) + ( 1 + tan²θ ) = k

{ we know, cosec²θ - cot²θ = 1   &  sec²θ - tan²θ = 1 
  }

cosec²θ  + sec²θ   = k

 \(\frac{sin²θ  + cos²θ }{ sin²θ.cos²θ }\)    = k

{ sin²θ  + cos²θ = 1 }

\(\frac{1 }{ sin²θ.cos²θ }\)    = k

cosec²θ.sec²θ = k

\(\sqrt {k }\) = cosecθ.secθ