The value of the integral
Question:

The value of the integral $\int_{0}^{\pi}|\sin 2 \mathrm{x}| \mathrm{dx}$ is

Solution:

Put $2 \mathrm{x}=\mathrm{t} \Rightarrow 2 \mathrm{dx}=\mathrm{dt}$

$\Rightarrow \mathrm{I}=\frac{1}{2} \int_{0}^{2 \pi}|\sin \mathrm{t}| \mathrm{dt}$

$=\int_{0}^{\pi}|\sin t| d t$

$=2$