One window displays the graph of X(t) (which you can alter in the appropriately labeled textbox), the point X(t

The other window displays the unit tangent vector T(t

The control window lists various functions and parameters used in defining those functions. To use one of those functions as X(t), type the function name in the X(t) textbox (e.g., type "cardioid(t)" to make X(t) a cardioid).

To change t

[<]: Decrease variable by one step.

[>]: Increase variable by one step.

[<<]: Decrease variable

[>>]: Increase variable

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. Click on the "Show position vector X(t