ANSWER
To graph the function
[tex]y=4cos(x)[/tex] we need to plot some few points within one period. Since the interval is not given, we shall use [tex][0,2 \pi][/tex]'
[tex]\left \begin{array}{cc}x&y=4cos(x)\\0 &4\\\frac{\pi}{2}&0 \\ \pi&-4\\\frac{3\pi}{2} &0\\2\pi&4\end{array}\right[/tex].
We plot the above points to obtain the graph as shown in the attachment.
