# What is the period of y=3 cos 5x?

##### 1 Answer
Oct 6, 2014

The period is $\omega = \frac{2 \pi}{B}$ where $B$ is the coefficient of the $x$ term

period$= \omega = \frac{2 \pi}{B} = \frac{2 \pi}{5}$

Enter the function after pressing the $Y =$ button

Set the view to show x values from $0$ to $\frac{2 \pi}{5}$

The calculator changes $\frac{2 \pi}{5}$ to its decimal equivalent.

Then press the GRAPH to verify that we see a period of the cosine functions.