Given
The function is given as
[tex]y=3cos\frac{\theta}{3}[/tex]Required
To determine the amplitude and period.
Explanation
The general trigonometric equation is
[tex]y=Acos(Bx-C)+D[/tex]
where A is the amplitude.
Compare with the given equaiton.
A =3.
Then the amplitude is 3.
Now , find the period.
[tex]P=\frac{2\pi}{B}[/tex]
Substitute the value of B in the expression.
[tex]P=\frac{2\pi}{(\frac{1}{3})}=6\pi[/tex]Answer
Hence the amplitude is 3 and period is
[tex]6\pi[/tex]
The graph of the equation is determined as
