Question 535398: Without graphing, determine the vertex of the given parabola:
y = -3x^2 - 6x - 8 Found 2 solutions by rfer, oberobic:Answer by rfer(16322) (Show Source):
You can put this solution on YOUR website! y = -3x^2 -6x -8
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The axis of symmetry is defined by x = -b/2a.
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-b/2a = -(-6)/(2*(-3) = 6/-6 = -1
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Then substitute x=-6 to find 'y'.
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y = -3(-1^2) -(6-1) -8
y = -3 +6 -8
y = -5
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The vertex is: (-1,-5).
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Of course, the graph is a good way to check this solution.
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