Graphing Trigonometric Functions

The sine function y = sin x and cosine function h = cos x are periodic functions. The fundamental period of each is 360º or 2π. To plot the graph of a sine or cosine function, follow these steps:

1. Find the values of the function at the points x = 0 and x = 2π.
2. Find the values of the function at some arbitrary points between 0 and 2π.
3. Find x when y = 0 or h = 0.