$x=\sqrt{5-y^{2}}+y$
$x=-\sqrt{5-y^{2}}+y$

$y=\frac{\sqrt{10-x^{2}}+x}{2}$
$y=\frac{-\sqrt{10-x^{2}}+x}{2}$

$x=\sqrt{5-y^{2}}+y$
$x=-\sqrt{5-y^{2}}+y\text{, }|y|\leq \sqrt{5}$

$y=\frac{\sqrt{10-x^{2}}+x}{2}$
$y=\frac{-\sqrt{10-x^{2}}+x}{2}\text{, }|x|\leq \sqrt{10}$