When a function duplicates its shape repeatedly along its domain, the function is said to be periodic, i.e., [math]f\left(x\right)=f\left(x+np\right)[/math] [math]p\in\mathbb{R}[/math][math]\forall n\in\mathbb{Z}[/math] [br]First, choose a value of the period [i]p[/i]. The function would repeat every length [i]p[/i].[br]Push the "play" button and move the orange point. You will draw a periodic function of period [i]p[/i].[br]Push "restart" to begin again ([b]CONTROL+F[/b] erases the graphic view)