Answer
$${\text{Click to see the graph}}$$
Work Step by Step
$$\eqalign{
& x = - \frac{{{y^2}}}{{16}} \cr
& {y^2} = - 16x \cr
& {\text{The equation is in the form }}{y^2} = 4px \cr
& {y^2} = - 16x:{\text{ }}{y^2} = 4px \cr
& - 16x = 4px \cr
& p = - 4 \cr
& {\text{The focus of a parabola of the form }}{y^2} = 4px{\text{ is}} \cr
& {\text{Focus }}\left( {p,0} \right) \Rightarrow {\text{Focus }}\left( { - 4,0} \right) \cr
& {\text{The directrix of a parabola of the form }}{y^2} = 4px{\text{ is}} \cr
& x = - p \Rightarrow x = 4 \cr
& \cr
& {\text{Graph}} \cr} $$
