Question 78007: Write an equation of a parabola with a vertex at the origin and a directrix at y=5. Found 2 solutions by stanbon, scott8148:Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Write an equation of a parabola with a vertex at the origin and a directrix at y=5.
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Plot the vertex point and draw the directrix line.
That implies the equation has the form (x-0)^2=4p(y-0)
and p=5 (the distance from the directrip to the vertex.
EQUATION:
20y=x^2
y=(1/20)x^2
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Cheers,
Stan H.
You can put this solution on YOUR website! vertex is mid-way between focus and directrix so focus is (0,-5)...parabola is locus of points equidistant from focus and directrix
for a point (x,y)...(y-5)^2=(x-0)^2+(y+5)^2...y^2-10y+25=x^2+y^2+10y+25...
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