Question

MEDAL AND FAN WILL BE AWARDED!!!
Does anyone know how to do this?
Write an equation for a graph that is the set of all points in the plane that are equidistant from the given point and the given line.
Focus(0,3) y=-1

The answer is: y=1/8x^2+1

Answer 1

This is the definition of a parabola.
The given line is what's called the "Directrix".

Mmm I'm trying to remember how to relate the focus point to a parabola.. gimme few minutes.

Answer 2

well isn't it the formula a= 1/4c?

Answer 3

and isn't the focus c? but I just don't know how to get the answer that I'm suppose to get

Answer 4

Romwill: zepdrix is correct when he says this:

This is the definition of a parabola.
The given line is what's called the "Directrix".


I'd suggest we graph both the focus (0,3) and the given line y=-1.

Answer 5

Rule: the vertex of the parabola is exactly half-way between the focus and the directrix.
Would one of you please find the vertex and graph it? Borrow my graph and add to it.

Answer 6

well we just have to write an equation

Answer 7

Yes, but to do that we have to know the location of the vertex. If you'd like to find the vertex without graphing it, fine. What are the x- and y-coordinates of the vertex?

Answer 8

um.................... I'm not sure exactly

Answer 9

that's why I've suggested drawing a graph and labeling the vertex.