Answer:
![y=[1]cos([(2\pi )/(3)]x)](https://img.qammunity.org/2023/formulas/mathematics/high-school/up010j4byteti8hdenv908k7ni0l5wwvsi.png)
Explanation:
Looking at the graph, we can see the domain to be from (0 , 2π).
Now we have to find one period that corresponds to cos(x).
The half-period of cos(x) for this graph appears to be pi/3 and adding another pi/3 gets us 2pi/3 to be our cosine period.
b = 2pi/3
a is the same range as cos(x). Range: (0,0)
y = [a] * cos ([b]*x)
y = [1] * cos([2pi/3]x)