関連ワード:  integrate x^3 cosx 2    integral of 3 cosx 2    integral of sinx 3 cosx 2    integral of 1 3 2sinx cosx    integral of 1 cosx 3 2    integral x 3cos x 2    integral of dx 3 2sinx cosx    what is the integral of x^3    integral of x^(3/2)