A parabola is the set of points equidistant
from a line, called the directrix, and a fixed point, called the
focus. Assume the focus is not on

the line. Construct a parabola given a fixed point for the focus
and a line (segment) for the directrix.

- Use an Action Button to generate the
parabola from an animation and trace of a constructed point,
for action click
**here**. - Repeat 9a with a trace of the tangent
line at the constructed point, for action click
**here**. - Use the locus command to generated the
parabola from a constructed point or the tangent line at that
point, for action click
**here**.