focus and directrix
- Author:
- Esther Gruenhut
Given point F (=focus), and line (=directrix).
Q is a point equidistant from the point and the line.
Try moving Q
Let , and .
How does changing the parameter affect the parabola?
And how about other points in the plane?
In the applet below, move around point P, and try to notice:
which points are closer to the focus, and which to the directrix?