Periodic function
function that repeats its values in regular intervals or periods / From Wikipedia, the free encyclopedia
In mathematics, a periodic function is a function which has a repeated pattern (a period) which is continued infinitely.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/a/a2/Sine.svg/320px-Sine.svg.png)
Examples of periodic functions are the trigonometric functions sine and cosine, which both have a period of .