Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Definite Integration

Question:

$\int_{\cos\,\cos^{-1}α}^{\sin\,\sin^{-1}β}|\frac{\cos(\cos^{-1}x)}{\sin(\sin^{-1}x)}|dx(α,β∈[0,1])$ is equal to:

Options:

1

1/2

$β-α$

None of these

Correct Answer:

$β-α$

Explanation:

As we have $\sin^{-1}β$ and $\cos^{-1}α$ defined,

If $α,β∈[0,1]$

$\cos(\cos^{-1})=x\,∀\,x∈[-1,1];\sin(\sin^{-1})=x\,∀\,x∈[-1,1]$

$\int\limits_{\cos\,\cos^{-1}α}^{\sin\,\sin^{-1}β}|\frac{\cos(\cos^{-1}x)}{\sin(\sin^{-1}x)}|dx=\int\limits_{α}^{β}1dx=β-α$