# Inverse Function Problem

Given $f(x) = mx^2 + 2x ,$ where $m$ is a constant and $f^{-1}\left[\frac{1}{2}\right] = -1$.Find the value of $m$
Although it certainly will work, it is not necessary to actually find the function $f^{-1}(x)$. If $y= f(x)$ then $x= f^{-1}(y)$. In $y= mx^2+ 2x$, replace x with -1, replace y with 1/2, and solve for m.