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Question 187486This question is from textbook
: Write an equation. The equation of a parabola such that the minimum value of y is -6 and the graph has x-intercepts 3 and 7.
This question is from textbook
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Write an equation. The equation of a parabola such that the minimum value of y is -6 and the graph has x-intercepts 3 and 7.
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Form: y = k(x-3)(x-7)
y = k(x^2 - 10x + 21)
y = kx^2 - 10kx + 21k
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minimum occurs when x = -b/2a = 10k/(2k) = 5
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Since the minimum y value is -6, f(5) = -6
f(5) = 25k - 50k + 21k = -6
-4k = -6
k = 3/2
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Equation:
y = (3/2)(x^2 - 10x + 21)
y = (3/2)x^2 - 15x + (63/2)
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Cheers,
Stan H.
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