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Re: geometry help
Posted:
Apr 26, 2014 12:06 AM


> For a parabola b^24ac = 0 so B^2 = 4 AC > If B=0 then either A or C = 0 > > So the equation becomes either > C.Y^2 + D.X + E.Y + F = 0 with axis // oX, or > A.X^2 + D.X + E.Y + F = 0 with axis // oY > > In either case 4 points are necessary to determine > the equation...
Hi Peter!
Without loss of genearlty we can divide out the above by F so that there remain three constants only. Accordingly, three points only need to be given to determine a parabola parallel to either oX or oY, as: y = a x^2 + b x + c and x = A y^2 + B y + C.
An inclined axis needs one more constant or one more point.
Best Regards Narasimham



