A例2计算nsin:x- sin xdx. 解∵f(x)=sin3x- sinx=cosx(sinx)2 T T sin'x-sin xdx=" cos x(sin x) )2dx 0 0 cosxisinx 2dx cos x )2dx 0 π元2 2(sinx)dsix-「r(s T sInx2a sinx 月0 =sInx sIn 5 0 5 上页例2 计算 解 sin sin . 0 3 5   x − xdx f x x x 3 5  ( ) = sin − sin ( )2 3 = cos x sin x    − 0 3 5 sin x sin xdx ( )   = 0 2 3 cos x sin x dx ( )   = 2 0 2 3 cos x sin x dx ( )   −  2 2 3 cos x sin x dx ( )   = 2 0 2 3 sin x d sin x ( )   −  2 2 3 sin x d sin x ( ) 2 0 2 5 sin 5 2  = x ( )   − 2 2 5 sin 5 2 x . 5 4 =