How do I find the vertex and directrix of a parabola

The equation is (x-4)^2 = 8(y+3). I found the vertex to be (4,-3). How do I find the rest?

(x - h)² = 4p(y - k)²

vertex(you knew) = (h, k)
p = distance between vertex and focus; distance between vertex and directrix

parabola opens up, so focus is point p units above vertex, directrix is horizontal line p units below vertex
F: (4, -1)
d: y = -5

http://www.khanacademy.org/math/algebra/conic-sections?k

Use those videos if you want to know HOW, if you want the answer, its right there because people on yahoo answers like to do your ez homework for you.

4a = 8
a = 2

directrix: y = -3 - 2 = -5

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