$$y = - 4 x ^ { 2 } + 4 x - 4$$
$x=\frac{-\sqrt{-y-3}+1}{2}$
$x=\frac{\sqrt{-y-3}+1}{2}$
$x=\frac{-\sqrt{-y-3}+1}{2}$
$x=\frac{\sqrt{-y-3}+1}{2}\text{, }y\leq -3$
$y=4\left(-x^{2}+x-1\right)$
