Answer
Refer to the graph below.
Work Step by Step
RECALL:
The function $y=a \cdot \cos{(bx)}$ has:
period = $\frac{2\pi}{|b|}$.
amplitude = $|a|$
The given function has $a=3$ and $b=2$.
Thus, the given function has:
period = $\frac{2\pi}{2}=\pi$
amplitude = $|3|=3$
One period of this function is in the interval $[0, \pi]$.
Divide this interval into four equal parts to obtain the key x-values $0, \frac{\pi}{4}, \frac{\pi}{2}, \frac{3\pi}{4}$.
To graph the given function, perform the following steps:
(1) Create a table of values using the key x-values listed above. (Refer to the table below.)
(2) Plot each point from the table of values then connect them using a sinusoidal curve. (Refer to the graph in the answer part above.)
