$$y = 4 x ^ { 2 }$$
$x=-\frac{\sqrt{y}}{2}$
$x=\frac{\sqrt{y}}{2}$
$x=\frac{\sqrt{y}}{2}$
$x=-\frac{\sqrt{y}}{2}\text{, }y\geq 0$
$y=4x^{2}$
