## Precalculus (6th Edition) Blitzer

vertex $(-1,5)$, focus $(0,5)$, and directrix $x=-2$; see figure.
Step 1. Rewrite the equation as $y^2-10y+25=4x-21+25$ or $(y-5)^2=4(x+1)$; we have $p=\frac{4}{4}=1$ Step 2. We can identify that this parabola opens to the right with a vertex at $(-1,5)$, focus at $(0,5)$, and directrix as $x=-2$ Step 3. We can graph the equation as shown in the figure.