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Despite both being conic sections, cutting up an ellipse won't yield you parabolas. An ellipse has two focal points to which the sum of the distances is constan
by est31 6y ago
Despite both being conic sections, cutting up an ellipse won't yield you parabolas. An ellipse has two focal points to which the sum of the distances is constant, while a parabola has a focal point and a directrix line to which the difference of the distances is constantly 0. Two different things.
- Koshkin 6y agoIsn’t a conic section made by cutting up, well, a cone?
- srtjstjsj 6y agoMore symmetrically, Every comic section has one focus and one directrix (and a semi-major axis for scale), eccentricity is the ratio of distance. Ellipse has eccentricity less than 1, and a parabola has eccentricity equal to 1.
- pdkl95 6y agoParabolas are just a special case of ellipses where one focus is infinitely far away. Vi Hart has a nice explanation: https://www.youtube.com/watch?v=v-pyuaThp-c https://www.youtube.com/watch?v=v-pyuaThp-c