How to evaluate $$\int_{0}^{1}\frac{\arctan x}{1+x^{2}}\ln\left ( \frac{1+x^{2}}{1+x} \right )\mathrm{d}x$$ I completely have no idea how to find the result.Mathematic gave me the following answer part of the integral $$\int_{0}^{1}\frac{\arctan x}{1+x^{2}}\ln\left ( 1+x^{2} \right )\mathrm{d}x=-\frac{1}{4}\mathbf{G}\pi +\frac{\pi ^{2}}{16}\ln 2+\frac{21}{64}\zeta \left ( 3 \right )$$ where $\mathbf{G}$ donates the Catalan's Constant.
But it can't evaluate the other part.So I'd like to know how to evaluate the original integral or the above integral.