Решенный интеграл вида ∫xsin^2(αx)dx

Solving an indefinite integral of the form ∫xsin^2(αx)dx by integration by parts, where α takes the values 1,2,3,4,5...n
An example of solving integrals for α=2,3,4
∫xsin^2(αx)dx, ∫xsin^2(2x)dx, ∫xsin^2(3x)dx, ∫xsin^2(4x)dx

The solution is in PDF format