How do you integrate #int xln(1+x)# using integration by parts?

1 Answer
Oct 22, 2016

#I=1/2x^2ln(1+x)-1/4x^2+1/2x-1/2ln(1+x)+C#

Explanation:

#intu(dv)/dxdx=uv-intv(du)/dxdx#

let #u=ln(1+x)=>(du)/dx=1/(1+x)#

#(dv)/dx=x=>v=1/2x^2#

#I=1/2x^2ln(1+x)-1/2int(x^2/(1+x))dx#

#I=1/2x^2ln(1+x)-1/2int(x-x/(1 +x))dx#

#I=1/2x^2ln(1+x)-1/2int(x-1+1/(x+1))dx#

#I=1/2x^2ln(1+x)-1/4x^2+1/2x-1/2ln(1+x)+C#