Решенный интеграл вида ∫xcos^2(αx)dx

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

The solution is in PDF format