Chapter 7 - Section 7.1 - Systems of Linear Equations in Two Variables - Exercise Set - Page 823: 114

amplitude $2$ period $\pi$ phase shift $\frac{\pi}{4}$ See graph.

Step 1. The amplitude can be found as $A=|-2|=2$ Step 2. The period can be found as $p=\frac{2\pi}{2}=\pi$ Step 3. The phase shift can be found as $\frac{\pi/2}{2}=\frac{\pi}{4}$ Step 4. See graph.