Question Number 121860 by Bird last updated on 12/Nov/20
![calculate ∫∫_([0,1]^2 ) ((arctan((√(x^2 +y^2 ))))/(x^2 +y^2 ))dxdy](Q121860.png)
$${calculate}\:\int\int_{\left[\mathrm{0},\mathrm{1}\right]^{\mathrm{2}} } \:\:\:\frac{{arctan}\left(\sqrt{{x}^{\mathrm{2}} +{y}^{\mathrm{2}} }\right)}{{x}^{\mathrm{2}} +{y}^{\mathrm{2}} }{dxdy} \\ $$