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View Full Version : Ellipse given n minimum points and knowing one of the focus


cptolemy
Jan10-11, 10:26 AM
Hi,

I think this is not homework - it's a general problem applyed to orbits.
I want to build an ellipse given the minimum n points (x,y) knowing that one of the focus (barycenter) is (0,0) - the other one can be elsewhere. My questions are:

1) How many points are needed? A unique ellipse needs five points. But in this case we know the focus.
2) How do I calculate the formula of that ellipse? Is the polar form more adequate?
3) How do I calculate the inclination of the major axis regarding the x axis?

Please give me - only if possible - the complete solutions; I'm a little bit lost here...

Kind regards, and thanks,

CPtolemy