What is the integral of ln(x+1)ln(x+1)?

1 Answer
Dec 23, 2014

Integration by Parts

int udv=dv-int vduudv=dvvdu


int ln(x+1) dxln(x+1)dx

by Substitution t=x+1 => dt=dxt=x+1dt=dx,

= int ln t dt=lntdt

by Integration by Parts with {(u=ln t => du ={dt}/t),(dv=dt => v=t):},

=t ln t - int dt

by evaluating the integral,

=t ln t - t+C

by putting t=x+1 back in,

=(x+1)ln(x+1)-(x+1)+C

(Note: You may also let the constant C include the last +1.)


I hope that this was helpful.