recall that to find the inverse of any expression, we start off by doign a quick switcheroo on the variables, and then solve for y.
[tex] \bf y=2x^2-8\implies \stackrel{\textit{switcheroo}}{\underline{x}=2\underline{y}^2-8}\implies x+8=2y^2 \\\\\\ \cfrac{x+8}{2}=y^2\implies \sqrt{\cfrac{x+8}{2}}=\stackrel{f^{-1}(x)}{y} [/tex]
