# Frequency of a Periodic Function

## Frequency of a Periodic Function

If f is a periodic function with period P, the frequency of f is equal to the inverse of P, or $$\frac{1}{\textrm{P}}$$.

### Educational Note

In the different areas of physics, including music (sound waves), the frequency refers to the number of times that a periodic phenomenon can be reproduced by unit of time or space. In the case of a periodic function, the unit considered is the one used on the x-axis of a Cartesian plane.

Here, the period is 4π and the frequency is equal to $$\dfrac{1}{4\pi}$$, which is approximately 0.08. This means that, over an axis length of 1 unit, the graph of f covers about 8% of a cycle.