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View Full Version : Parabolas with vertex (0,0). How to find focus?


IHateMath_1516
Mar 11, 2012, 01:37 PM
How do I find the focus of a parabola with a vertex of (0,0)?

ebaines
Mar 12, 2012, 10:19 AM
The general formula for a parabola is:


4p(y-y_0) = (x - x_0)^2


where (x_0, y_0) is the vertex and p is the distance from the vertex to the focus. For a parabola whose vertex is at (0,0) this becomes:


4py = x^2


As you can see the position of the focus depends on the value of p.