SOLUTION: find the equation of a parabola with vertex (-3,1) and directrix y=2

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Question 456554: find the equation of a parabola with vertex (-3,1) and directrix y=2
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
The form of the equation is 4a%28y-k%29+=+%28x-h%29%5E2, where (h,k) is the vertex.
==> 4a%28y+-+1%29+=+%28x+%2B+3%29%5E2
a = directed distance from the focus to the vertex (which in absolute value is equal to the distance between the vertex and the directrix.) Hence a = -1, and therefore, the equation is
-4%28y+-1%29+=+%28x+%2B+3%29%5E2.