Question 172563: Find the vertex, focus, and directrix of the parabola given by x^2 - 6x - 12y - 15 = 0
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Find the vertex, focus, and directrix of the parabola given by
x^2 - 6x - 12y - 15 = 0
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x^2 - 6x + ? = 12y + 15 + ?
x^2 -6x + 9 = 12y + 15 + 9
(x-3)^2 = 12(y + 2)
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Vertex: (3,-2)
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Since 4p = 12, p = 3
so the focus is at (3,-2+3) or (3,1)
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directrix: x = 3
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Cheers,
Stan H.
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