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rockergurl500
Feb 1, 2010, 11:13 PM
1. Focus (1,0); directrix x=-3

2. Focus (0,-3); vertex (2,-3)

3. Vertex (5,1); directrix x=3

Please refresh my memory on this because I literally am drawing a blank :/
Thanks!

Unknown008
Feb 2, 2010, 08:07 AM
The general formula for a parabola with horizontal axis (all three of yours have horizontal axes) is

(y-k)^2=4p(x-h)

Vertex = (h, k)
Directrix : y = k-p
Focus : (h, k+p)

I think that's enough. Care to give it a try? Post your answers! :)