## Precalculus (6th Edition) Blitzer

Step 1. Graph $y=2sin(\frac{x}{2})$ as shown in the figure (red curve). Step 2. Using the property $csc(\frac{x}{2})=\frac{1}{sin(\frac{x}{2})}$, invert the values of the original curve to obtain the new curve (blue). Step 3. Note that the zeros of the red curve become the vertical asymptotes of the blue curve.