Exploring Conic Sections

Chose from three different conic sections to explore. But what about the fourth conic section??? [Hint: What happens if you drag poing F1 out of the circle in the ellispe construction...]

This is a Java Applet created using GeoGebra from www.geogebra.org - it looks like you don't have Java installed, please go to www.java.com

Dixie Christensen, 23 October 2013, Created with GeoGebra