How do you integrate int xsin2xxsin2x by integration by parts method?

1 Answer
Jan 16, 2017

int xsin2xdx = -1/2xcos2x +1/4sin2xxsin2xdx=12xcos2x+14sin2x

Explanation:

As:

d(cos2x) =-2sin2x dxd(cos2x)=2sin2xdx

we can integrate by parts in this way:

int xsin2xdx = -1/2 int x d(cos2x) = -1/2 xcos2x +1/2 int cos2x dx= -1/2xcos2x +1/4sin2xxsin2xdx=12xd(cos2x)=12xcos2x+12cos2xdx=12xcos2x+14sin2x