I have been trying to solve this integral for a while but nothing works. I tried using WolframAlpha.com but the answer is a very nasty one, and my Calculus book gives a nice integral for this, using x= (1-u)/(1+u), but why would they do that? The answer is (pi/8)ln(2). Thank you in advance!.

∫ ln(x+1)/(x^2+1) from 0 to 1