Chapter SH, Problem 12.18EP

To determine

To find: The amplitude, period of given function. And then graph the function.

Answer to Problem 12.18EP

The amplitude of the given function is $3$ and the period is $2\pi$ and the graph is shown below.

Explanation of Solution

Given:

The given function is:

  $y=3\cos \theta$ .

Consider the cosine function:

  $y=A\cos \left(B\left(x-C\right)\right)+D$

The amplitude and period of the cosine function is given as:

The amplitude is $\left|A\right|$ .

The period is $\frac{2\pi }{B}$ .

By comparing the given function by the above function the amplitude and period are as given:

The amplitude of the given function is $3$ .

The period is $2\pi$ .

The graph of the given function is as:

  

Therefore the amplitude of the given function is $3$ and theperiod is $2\pi$ and the graph is shown above.