Let L be a line in the plane, F be a point in the same plane outside of the line L. Let X be any point in the same plane, dL be the distance from X to L (so it is a perpendicular line). df be the distance from X to F. Let us consider the locus of all points X that df/dl = e where e is a constant positive number.
If e = 1, we have our standard definition of a parabola. The remarkable fact is that if 01, the locus is a hyperbola. So, we have the uniform definition of all three conics depending only on the value of eccentricity e.
Can you start with a star (*) above the line L , express it in coordinates and by a series of algebraic equations, get our standard equations of an ellipse and hyperbola (may be – shifted) depending on the value of e (01).
Can you please write a complete proof in general form and for the coordinates of the point P and equation of line L you can use specific values which are convenient for you.
2007-04-07
10:31:02
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2 answers
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asked by
╦╩╔╩╦ O.J. ╔╩╦╠═
6
in
Science & Mathematics
➔ Mathematics