関連ワード:  integration of x sin 3x    integration of x sin 3x dx    integration of x sin 3x sin 5x dx    integration of x sin 3x dx is equal to    integral of x sin 3x from 0 to pi    integration of cos x sin 3x    integration of cos x sin 3x dx    integration of x 2 sin 3x dx    integration of x 2 sin 3x    integration of x 3 sin 3x dx