How it works ?
In the applets below, graphs of the functions f(x) = sin (x) and f(x) = cos (x) are shown. In each applet, drag the BIG WHITE POINT along the graph of the displayed function.
The y-coordinate of the point being traced out = the slope of the tangent line to the graph of f. Interact with each applet for a few minutes, then answer the questions that follow.