This demo includes two windows. The first displays the curve X(t) that you can alter in the appropriately labeled textbox, the point X(t0), and the velocity vector X'(t0) with base X(t0). The second window displays the velocity vector X'(t0) with its base at the origin and the curve X'(t0) traced out by the head of the vector. You also have the option of showing the acceleration vector X''(t0) tangent to the curve in the second window at the point X'(t0) by clicking the appropriate checkbox in the control window.
Change the value of t0 and other variables as in earlier demos.
As in earlier demos, there are "Show entire curve" and "Show Color Spectrum" options. "Show Color Spectrum" will also color the velocity vector and the velocity curve.