Ellipse from two foci and point

This applet shows an ellipse made from two foci and a point on the ellipse. Notice that as you move point P around, the sum of the lengths of the two dashed red segments is constant. Physically, you can make an ellipse with two pushpins (at the foci) and a piece of string tied to each foci. Here's an example: [url]http://www.youtube.com/watch?v=7UD8hOs-vaI[/url]. To change the shape of the ellipse, you can move the foci, as well as the small blue point.

 

David Beydler

 
Type de ressources
Activité
Balises
ellipse  foci  focus 
Tranche d'âges
19+
Langue
English (United States)
 
 
Version GeoGebra
4.2
Vues
6156
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Licence
CC-BY-SA, GeoGebra Terms of Use
Matériels dérivés
Ellipse from two foci and point
partagé par tobibrooks
 
 
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