Answer
The amplitude and period of $y=3\cos 2\pi x$ are $3$ and $\text{1}$, respectively. The table is shown below:
Work Step by Step
The amplitude of $y=3\cos 2\pi x$ can be obtained by comparing the provided equation with the equation $y=A\cos Bx$ and it is given below
$\begin{align}
& \left| A \right|=\left| 3 \right| \\
& =3
\end{align}$
And the period is given by
$\begin{align}
& \frac{2\pi }{B}=\frac{2\pi }{2\pi } \\
& =1
\end{align}$
Now, we have to plot the graph of the given equation for $-4\le x\le 4$:
The quarter period is:
$\text{Quarter period}=\frac{\text{Period}}{4}=\frac{1}{4}$
Use the below coordinates to draw a smooth graph as shown above.
