Answer:
Amplitude = 3
Explanation:
The amplitude of a periodic function is the vertical distance from the midline to either the peak or trough of the function. In other words, it is the absolute value of half the difference between the y-values of the function's maximum and minimum points.
From observation of the graphed periodic function, the maximum y-value is y = 4 and the minimum y-value is y = -2. Therefore, the amplitude is:

So, the amplitude of the graphed periodic function is 3.