This demo includes two graphical display windows.
The window "Curve: X(t)" displays the curve X(t), the point X(t0),
the unit tangent and principal normal vectors T(t0) and
P(t0) with their tails at X(t0), and the
osculating plane at X(t0).
The window "T(t) and P(t)" displays the unit tangent and principal normal
vectors T(t0) and P(t0), the unit sphere on
which their heads are constrained to lie, and the osculating plane from
the "Curve: X(t)" window, going through the origin instead of X(t0).
You can change t0 and X(t) in the control window. The
includes a list of functions that you can use for X(t), along with
parameters used to define those functions.