Answer
$$\pi $$
Work Step by Step
$$\eqalign{
& \int_0^\pi {x\sin x} dx \cr
& {\text{Integrate by tables, use }}\int {u\sin udu} = \sin u - u\cos u + C \cr
& \int_0^\pi {x\sin x} dx = \left[ {\sin x - x\cos x} \right]_0^\pi \cr
& {\text{Evaluate}} \cr
& = \left[ {\sin \pi - \pi \cos \pi } \right] - \left[ {\sin 0 - 0\cos 0} \right] \cr
& = 0 - \pi \left( { - 1} \right) - 0 \cr
& = \pi \cr} $$