This presentation is a thorough interactive introduction to the graphs of sine and cosine functions, intended to be used after students learn the unit circle. It generates the graphs of sine and cosine by tracking the horizontal and vertical coordinates of a point on an animated unit circle on the vertical axis and the angle measure (in radians) on the horizontal axis. The points generate automatically and at the end they are connected by a smooth sinusoidal curve and the functions are labeled with the appropriate equation. The cosine graph is oriented vertically until the end, when it is rotated to become the familiar cosine function. This may be displayed in front of the class or shared with the students to explore on their own.