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

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

$y=-2x^{2}+4x-3$