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## #1 2005-08-08 03:42:31

ASh
Guest

### coordinates of a point on an ellipse

How can I find coordinates of a point on an ellipse which is in a rectangle if all I know is the height and the width of the rectangle. The point is located approx. where 2 circles, that make up the ellipse, connect. It may be located exactly at this point, if this helpls.
Thank you.

## #2 2005-08-08 17:22:11

ganesh
Registered: 2005-06-28
Posts: 24,221

### Re: coordinates of a point on an ellipse

The equation of an ellipse is given by
x²/a² + y²/b² = 1
The height and the width of the rectangle would be 2b and 2a.
Now, from this information, get the value of ba and a.
Substitute in the equation for the ellipse.
You get the equation of the ellipse.
Thereafter, give values for x like -2, -1, 0, 1, 2 etc. and find the corresponding values of y.

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

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## #3 2005-08-10 12:28:32

wcy
Member
Registered: 2005-08-04
Posts: 117

### Re: coordinates of a point on an ellipse

if the ellipse is not centred at the origin, the equation becomes,

(x-p)²/a² + (y-q)²/b² = 1

where (p,q) is the centre

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Ash
Guest

Thanks a lot

## #5 2005-08-11 09:45:23

MathsIsFun
Registered: 2005-01-21
Posts: 7,684

### Re: coordinates of a point on an ellipse

Icecream Sundaes for ganesh and wcy !

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

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