Answer:
a.
Period = π
Amplitude = 4
b.
Maximum at: x = 0, π and 2π
Minimum at: x = π/2 and 3π/2
Zeros at: x = π/4, 3π/4, 5π/4 and 7π/4
Step-by-step explanation:
Part a:
Amplitude represents the half of the distance between the maximum point and the minimum point of the function. So the easy way to find the amplitude is: Find the difference between maximum and minimum value of the function and divide the difference by 2.
So, amplitude will be: [tex]\frac{Maximum-Minimum}{2}=\frac{4-(-4)}{2}=\frac{8}{2}=4[/tex]
Therefore, the amplitude of the function is 4.
Period is the time in which the function completes its one cycle. From the graph we can see that cosine started at 0 and completed its cycle at π. After π the same value starts to repeat. So the period of the given cosine function is π.
Part b:
From the graph we can see that the maximum values occur at the following points: x = 0, π and 2π
The scale on x-axis between 0 and π is divided into 4 squares, so each square represents π/4
Therefore, the minimum value occurs at x = π/2 and 3π/2
Zeros occur where the graph crosses the x-axis. So the zeros occur at the following points: π/4, 3π/4, 5π/4 and 7π/4
