[color=#0000ff][b]Periodic Function [br][/b][/color][br] A function [math]f[/math] is periodic if there is a positive number [math]p[/math] such that [math]f\left(t+p\right)=f\left(t\right)[/math] for every [math]t[/math]. The least such positive number is the period of [math]f[/math][color=#0000ff][br][b][br]Periodic Properties of Sine and Cosine Functions.[br][/b][br][/color]The sine and cosine functions repeat their values in any interval of length [math]2\pi[/math]. so the period of sine and cosine function is [math]2\pi[/math][br][br]That is [math]sin\left(t+2\pi\right)=sint[/math] [math]cos\left(t=2\pi\right)=cost[/math]

Use the sliders and input boxes to understand the graph of sine and cosine functions