$\lim _{x \rightarrow \frac{\pi^{-}}{2}}\left[\frac{2\left(\sin x-\sin ^{3}
x\right)+\sin x-\sin ^{3} x}{2\left(\sin x-\sin ^{3} x\right)-\sin x+\sin ^{3}
x}\right]$
$\lim _{n \rightarrow \frac{\pi}{2}}\left[\frac{3\left(\sin x-\sin ^{3}
x\right)}{\left(\sin x-\sin ^{3} x\right)}\right]=3$
$\lim _{x \rightarrow \frac{\pi}{2}}\left[\frac{2\left(\sin x-\sin ^{3}
x\right)+\sin x-\sin ^{3} x}{2\left(\sin x-\sin ^{3} x\right)-\sin x+\sin ^{3}
x}\right]$
\(=3\)
So, \(f(x)\) is continuous at \(x=\frac{\pi}{2}\)
LHD \(=\) RHD \(=0\) (By first principle)