$x=-\frac{\sqrt{2y+4}}{2}-1$
$x=\frac{\sqrt{2y+4}}{2}-1$

$x=-\frac{\sqrt{2y+4}}{2}-1$
$x=\frac{\sqrt{2y+4}}{2}-1\text{, }y\geq -2$

$y=2x\left(x+2\right)$