- #1

DaveC426913

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- How does an ellipse defined by two foci relate to an ellipse defined by one focus?

An ellipse is a conic section - a slice through a cone. The axis of the cone coincides with the focus of the ellipse.(Correct?)

But ellipses can have two foci, not just one, as shown by this method of construction:

Questions:

1. Is F1 in the diagram the same as the axis of the conic section?

2. Does F2 have any correlation in the conic model?

3. Is there some way that these two

Questions:

1. Is F1 in the diagram the same as the axis of the conic section?

2. Does F2 have any correlation in the conic model?

3. Is there some way that these two

*apparently*unrelated definitions of an ellipses are two sides of the same coin?