Write an equation for the parabola with focus (0, 0) and directrix y = 1.

I got -x^2 - 2y + 1, but how do I get it in the form y - k = 1/4p(x - h)^2?

2 answers

My equation was :
x^2 = 2y + 1
(Yours in not even an equation.)

manipulating this:
y = (1/2)(x^2) - 1/2
from this I can read that the vertex is (0,-1/2) which is true according to the focus - directrix property in that the vertex is midway between the focus and the directrix.

or

y + 1/2 = (1/2)(x - 0)^2
But that equation has a directrix of y = -1.