Parabola with a Trace
by
Rob Walsh
A parabola is the set of points equidistant from a line, called the directrix, and a fixed point, called the focus.
Construct a parabola given a focus and directrix.
a. Use an Action Button to generate the parabola from an animation and trace of a constructed point.
b. Repeat the construction with a trace of the tangent line at the constructed point.