## Algebra and Trigonometry 10th Edition

$y^2=-9x$
Parabola in the standard form with the vertex at origin (horizontal axis): $y^2=4px$ $6^2=4p(-4)$ $36=-16p$ $p=-\frac{36}{16}=-\frac{9}{4}$ $y^2=4(-\frac{9}{4})x$ $y^2=-9x$