## Precalculus (6th Edition) Blitzer

If $\theta \max =\pi$, the graph is drawn once.
The above plot is for $\theta =\pi .$ From the plot, it can be observed that from $\theta =0\,\text{to}\,\theta \text{=}\pi$, the curve is plotted exactly once. Beyond $\theta =\pi$, the curve retracts its path again.