This page uses JavaSketchpad, a World-Wide-Web component of The Geometer's Sketchpad. Copyright © 1990-2001 by KCP Technologies, Inc. Licensed only for non-commercial use.
Conics defined by Eccentricity
1. Move the slider for eccentricity and see what kind
of conic section you get.
2. Move the focus to see what impact that has on the figure.
3. Move a point on the directrix to show that no matter what point is
taken on the curve, the ratio of the distance to the focus over the distance
to the directrix always equals the eccentricity.