Answer:
Xmin = π/3 and Xmax = 7π/3
Step-by-step explanation:
I assume that the function is:
y = 5 + 3 cos² (x − π/3)
cos² x has a period of π, so to graph two periods, you need a domain that is 2π wide, so:
Xmax − Xmin = 2π
You can choose any values you want for Xmax and Xmin, so long as they are 2π units apart. To make it easy to graph, you'll probably want to choose Xmin = π/3 and Xmax = 7π/3.
Graph:
desmos.com/calculator/9w3pptakde