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#1 2007-12-26 01:01:50
- Identity
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- Registered: 2007-04-18
- Posts: 934
Foci of an Ellipse
The book says that the distance c between the centre of an ellipse and a focus of an ellipse
can be found according to
, but I can't see how they derived this. I've tried looking for applications of Pythagoras' theorem but I'm getting nowhere. ThanksLast edited by Identity (2007-12-26 01:03:05)
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#2 2007-12-27 15:37:39
- kevinant
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- Registered: 2007-12-27
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Re: Foci of an Ellipse
You forget Eccentricity!
eccentricity of eclipse is:
the coordinate of the foci is (ae,0) (assme b<a)
therefore the focal distance to the origin is as follows:
Therefore (add absulte sign when a<b)
c²= |a²-b²|
Last edited by kevinant (2007-12-27 15:40:03)
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