$4\sqrt[\phantom{2}]{2}$

Q$).$ Change the cartesian integral

${\displaystyle \underset{0}{\overset{1}{}}}{\displaystyle \underset{-\sqrt[\phantom{2}]{1-y^2}}{\overset{\sqrt[\phantom{2}]{1-y^2}}{}}}(x^2+y^2)dxdy$

into an equivalont Polar integral and then evahirate the polar integraal.