Question:
Evaluate: $\int \sin x \sqrt{1-\cos 2 x} d x$
Solution:
$\Rightarrow 2 \sin ^{2} x=1-\cos 2 x$
We can substitute the above result in the given equation
$\therefore$ The given equation becomes
$\Rightarrow \int \sin x \sqrt{2 \sin ^{2} x}$
$\Rightarrow \int \sqrt{2} \sin ^{2} x$
$\sin ^{2} x=\frac{1-\cos 2 x}{2}$
$\Rightarrow \frac{\sqrt{2}}{2} \int 1-\cos 2 x d x$
$\Rightarrow \frac{1}{\sqrt{2}} \int d x-\frac{1}{\sqrt{2}} \int \cos 2 x d x$
$\Rightarrow \frac{x}{\sqrt{2}}-\frac{1}{2 \sqrt{2}} \sin (2 x)+c$