How do I evaluate the indefinite integral cot5(x)sin4(x)dx ?

1 Answer
Apr 23, 2018

cos2x+14sin4x+ln|sinx|+c

Explanation:

cot5xsin4x=cos5xsin5xsin4x=cos5xsinx=cos4xcotx=(1sin2x)2cotx=(12sin2x+sin4x)cot=cotx2sinxcosx+sin3xcosx

So

cot5xsin4xdx=cotxdx2sinxcosxdx+sin3xcosxdx

Now let u=sinx and du=cosxdx and v=cosx and dv=sinxdx

cotxdx+2sinxcosxdx+sin3xcosxdx=ln|sinx|2vdv+u3du=ln|sinx|+v2+14u4+c=cos2x+14sin4x+ln|sinx|+c