Question

Find the standard form of the equation of the parabola with a focus at (0, -9) and a directrix y = 9.

Answer 1

@satellite73

Answer 2

First find the vertex.

Answer 3

vertex is (0, 0)?

Answer 4

Yes

Answer 5

Now find the difference between the vertex and the vertex. We call this \(p\).

Answer 6

whoops

Answer 7

Difference between focus and vertex

Answer 8

9?

Answer 9

Well, it's \(-9\).

Answer 10

Anyway, equation will be given by: \[
(x-x_0)^2=4p(y-y_0)
\]Where \((x_0,y_0)\) is the vertex, and \(p\) is what we already discuss.

Answer 11

x^2 = -36y

Answer 12

Yes

Answer 13

That was a lot easier than I thought...

Answer 14

Thanks :)

Answer 15

no problem