Chapter 14 Trigonometric Graphs, Identities, and Equations - 14.5 Write Trigonometric Functions and Models - 14.5 Exercises - Mixed Review - Page 947: 31

$y^2=-16x$

a) The general form of the equation of a parabola with vertex at $(0,0)$ is given by $x^2=4py$ and the focus is: $F:(0,p)$ b) The general form of the equation of a parabola with vertex at $(0,0)$ is given by $y^2=4px$ and the focus is: $F:(p,0)$ For the given problem, we have $y^2=-16x$