Let $ denote the integral symbol, as I am limited here by my keyboard.
Recall the formula for integration by parts:
$ u.(dv/dx) dx = uv - $ u(dv/dx) dx
So to find $pi0x.sin(x) dx, we must allocate x and sin(x) to u and (dv/dx). Integrating sin(x) is simpler than integrating x, so let x = u and sin(x) = (dv/dx).
From the formula, we also need to know v and (du/dx), which we can find by integrating (dv/dx) and differetiating u. So:
(du/dx) = (d/dx)x = x
v=$(dv/dx)dx = $sin(x) dx = -cos(x)
So now we have:
$pi0x.sin(x) dx = [x.-cos(x)]pi0 - $pi0-cos(x) dx
= (pi.1 - 0) + $pi0cos(x) dx
=pi + [sin(x)]pi0
=pi + (0 -0)
= pi.