This demo displays the cycloid given by X(t) = (Rt – rsin(t), R – rcos(t)), along with rolling wheel which contains a point which traces
out the cycloid. To change any of the variables R, r, or t_{0},
use the following keys on the
appropriate line in the control window:

[<]: Decrease variable_{} by one step.

[>]: Increase variable_{} by one step.

[<<]: Decrease variable until it reaches its minimum value.

[>>]: Increase variable_{} until it reaches its maximum
value.

By default, the demo shows the point tracing out the curve, so that
only part of it is shown. To show the entire curve, check the box "Show
entire curve" by clicking on it.