#### Answer

2

#### Work Step by Step

The amplitude of a periodic function is half the difference between its maximum and minimum values.
According to the graph, the maximum value is 8 while the minimum value is 4. Therefore, the amplitude is:
Amplitude$=\frac{1}{2}$(Max-Min)
Amplitude$=\frac{1}{2}(8-4)$
Amplitude$=\frac{1}{2}(4)$
Amplitude$=2$