## Precalculus (6th Edition) Blitzer

$y=4$, see graph.
Step 1. Rewrite the equation as $r=\frac{4sin\theta}{cos^2\theta}$ or $r\ cos\theta =4cot\theta$ Step 2. Using $x=r\ cos\theta$ and $cot\theta=\frac{x}{y}$, we have $x=\frac{4x}{y}$ which gives $y=4$ Step 3. We can graph this line function as shown in the figure.