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