Mathematics - Application of Derivative Question with Solution | TestHub

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

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

$f$ is increasing $\left(0,\frac{\pi }{4}\right)$ and decreasing in $\left(\frac{\pi }{4},\frac{\pi }{2}\right)$

$f$ is decreasing is $\left(0,\frac{\pi }{4}\right)$ and increasing in $\left(\frac{\pi }{4},\frac{\pi }{2}\right)$