Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Applications of Derivatives

Question:

The function $f(x)=log(\sin x)$ is ____________.

Options:

strictly increasing in $\left(0, \frac{\pi}{2}\right)$

strictly decreasing in $\left(0, \frac{\pi}{2}\right)$

strictly increasing in $\left(\frac{\pi}{2}, 0\right)$

neither increasing nor decreasing in $\left(\frac{\pi}{2}, 0\right)$

Correct Answer:

strictly increasing in $\left(0, \frac{\pi}{2}\right)$

Explanation:

$f(x)=log(\sin x)$

so differentiating wrt x

$f'(x) = \cot x$ in $(0,\frac{π}{2})$  $\cot x>0$

$f(x)$ → increasing in $(0,\frac{π}{2})$