Question Number 121713 by mnjuly1970 last updated on 11/Nov/20
$$\:\:\:\:\:…\:{advanced}\:\:{calculus}… \\ $$$$\:{please}\:\:{prove}: \\ $$$$\Phi=\int_{\mathrm{0}} ^{\:\infty} {arctan}\left(\frac{\mathrm{2}{x}}{\mathrm{1}+{x}^{\mathrm{2}} }\right)\frac{{dx}}{{x}}\:=\pi{ln}\left(\mathrm{1}+\sqrt{\mathrm{2}}\:\right) \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:…{m}.{n}… \\ $$