A dancer is practicing spinning and wants to know her velocity. She has her teacher time her, and finds out she can spin once around in 5 seconds. The graph below shows the edge of her skirt, point G, as it flows and spins counterclockwise in a circle. Point G is the “position” of the edge of her skirt at that point in time. She uses this to find the derivative or her “velocity”. The velocity is shown below as the first derivative graph.

t | ||||

-3 | 0 | 3 | ||

position | ||||

velocity |