## Precalculus (10th Edition)

A periodic function is a function such that after a period of $p$ the function's value is the same, hence if the smallest period is $p$, then $f(x)=f(x+p)$ for all $x$ in the domain of the function.
A periodic function is a function such that after a period of $p$ the function's value is the same, hence if the smallest period is $p$, then $f(x)=f(x+p)$ for all $x$ in the domain of the function.