Answer
$4$
Work Step by Step
We know that $\int x^{n} dx=\dfrac{x^{n+1}}{n+1}+C$
where $C$ is a constant of proportionality
and $\int \sin x dx=\cos x +c$
$\int_{0}^{\pi} (2\sin x-\sin 2x) dx=[-2 \cos x+\dfrac{\cos 2x}{2}]_0^{\pi}$
or, $=-2[\cos \pi-\cos 0]+\dfrac{1}{2} (\cos 2 \pi-\cos 0)$
or $=(-2)(-1)+2=4$
