Change the Cartesian integral into an equivalent polar integral. Then evaluate the polar integral.

${\displaystyle \underset{-1}{\overset{0}{}}}{\displaystyle \underset{-\sqrt[\phantom{2}]{1-x^2}}{\overset{0}{}}}\frac{3}{1+\sqrt[\phantom{2}]{x^2+y^2}}dydx$

Change the Cartesian integral into an equivalent polar integral.

${\displaystyle \underset{-1}{\overset{0}{}}}{\displaystyle \underset{-\sqrt[\phantom{2}]{1-x^2}}{\overset{0}{}}}\frac{3}{1+\sqrt[\phantom{2}]{x^2+y^2}}dydx={\displaystyle \underset{}{\overset{}{}}}{\displaystyle \underset{0}{\overset{\phantom{}}{}}}drd$

$($Type exact answers, using $$ as needed.$)$

The value of the double integral is $$

$($Type an exact answer, using $$ as needed.$)$