SOLUTION: FIND THE EQUATION OF THE PARABOLA WITH THE GIVEN FOCUS AND DIRECTRIX. focus (-4,5) directrix y = 4

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Question 316174: FIND THE EQUATION OF THE PARABOLA WITH THE GIVEN FOCUS AND DIRECTRIX.
focus (-4,5) directrix y = 4
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
The y coordinate of the vertex is the midpoint of the line connecting the focus and perpendicular to the directrix.
Vy= (5+4)/2=4.5
Vertex:(-4,4.5)
Using the vertex form,
y=a%28x-%28-4%29%29%5E2%2B4.5
y=a%28x%2B4%29%5E2%2B4.5
where a is any non-zero constant.

Shown above are a=1 in red and a=3 in green.