How do I evaluate the indefinite integral intcot^5(x)*sin^4(x)dx ?

1 Answer
Apr 23, 2018

cos^2x+1/4sin^4x+lnabssinx+"c"

Explanation:

cot^5xsin^4x=cos^5x/sin^5xsin^4x=cos^5x/sinx=cos^4xcotx=(1-sin^2x)^2cotx=(1-2sin^2x+sin^4x)cot=cotx-2sinxcosx+sin^3xcosx

So

intcot^5xsin^4xdx=intcotxdx-int2sinxcosxdx+intsin^3xcosxdx

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

intcotxdx+int-2sinxcosxdx+intsin^3xcosxdx=lnabssinx int2vdv +intu^3du=lnabssinx+v^2+1/4u^4+"c"=cos^2x+1/4sin^4x+lnabssinx+"c"