For a function of the form:
[tex]y=acos(b\theta)[/tex]
a = amplitude = 2
b = angular frequency = 1/4
The period can be calculated as follows:
[tex]\begin{gathered} T=\frac{2\pi}{b} \\ So: \\ T=\frac{2\pi}{1/4} \\ T=8\pi \end{gathered}[/tex]
Now, we can graph the function easily:
