Question

Find Stationary points of $f\left(x\right)=\sin x$, where $0<x<2\pi$

Answer 1

$f\left(x\right)=\sin x{f}^{\prime }\left(x\right)=\cos x$

For Stationary points $f\left(x\right)=0\cos x=0x=\frac{\pi }{2},\frac{3\pi }{2}$