Question

The value of the integral $\underset{0}{\overset{\pi }{\int }}|\sin 2x|dx$ is

Answer 1

Answer: 2

Put $2x=t\Rightarrow 2dx=dt$
$\Rightarrow I=\frac{1}{2}\underset{0}{\overset{2\pi }{\int }}|\sin t|dt$
$=\underset{0}{\overset{\pi }{\int }}|\sin t|dt$
$=2$