Solving Difficult Integral Homework: \int_0^1\frac{ln(1+x)}{1+x^{2}} dx

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Homework Statement



I'm stuck with this definite integral : \int_0^1\frac{ln(1+x)}{1+x^{2}} dx

Homework Equations



The various "standard integrals".

The Attempt at a Solution



I just don't know where to start, or how to do it. I tried various substitutions but none of them worked; I also tired doing it by parts but that didn't work either.
 
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Okay, I got that. Thanks.
I knew of the identity, but didn't know I'd have to use it after making a substitution.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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