Замена x - sin x = t; dt = (1 - cos x) dx
t(π) = π - sin π = π - 0 = π; t(2π) = 2π - sin 2π = 2π - 0 = 2π
[m]\int \limits_{\pi}^{2\pi} \frac{1-\cos x}{(x - \sin x)^2} dx = \int \limits_{\pi}^{2\pi} \frac{dt}{t^2} = - \frac{1}{t} |_{\pi}^{2\pi} = -\frac{1}{2\pi} + \frac{1}{\pi} = \frac{1}{2\pi}[/m]