Question 85942This question is from textbook College Algebra
: Find the vertex, focus, and directrix of the parabola given by each equation. Sketch the graph.
18. 3x+y^2+8y+4=0
This question is from textbook College Algebra
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 each equation. Sketch the graph.
18. 3x+y^2+8y+4=0
Form: (y-k)^2=4p(x-h)
y^2+8y+(8/2)^2 = -3x-4+(8/2)^2
(y+4)^2 = -3x+12
(y+4)^2 = -3(x-4)
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4p=-3
p=-3/4
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Vertex at (h,k); (4,-4)
focus at (h+p,k); (4-3/4,-4) = (11/4,-4)
directrix:at x=h-p; x= 4-(-3/4)) = 19/4
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Cheers,
Stan H.
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