Integral of a power of a sine:
If the correct factors are present, this can be handled by the Power rule for integrals:
, where and using the derivative of the sine,
Hence a combination of factors in the original problem can be replaced:
With this substitution, we get
Finally, we substitute for u to get the result in terms of x:
Notice that the argument of the resulting trig function is the same as that in the original problem.