SOLUTION: Find the maximum y value on the graph of y=f(x) f(x)=-x^2+8x+1

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Question 630632: Find the maximum y value on the graph of y=f(x)
f(x)=-x^2+8x+1
Found 2 solutions by reviewermath, stanbon:
Answer by reviewermath(1029) About Me  (Show Source):
You can put this solution on YOUR website!
The x-coordinate of the vertex is -b%2F2a+=+-8%2F2%28-1%29+=+4 and the y-coordinate is +f%284%29+=+-4%5E2+%2B+8%284%29+%2B+1+=+highlight%2817%29. Since a < 0, y = f(x) has a maximum value. The maximum value is highlight%2817%29.
The graph is
+graph%28+400%2C+400%2C+-3%2C+10%2C+-4%2C+20%2C+-x%5E2%2B8x%2B1%29+

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Find the maximum y value on the graph of y=f(x)
f(x)=-x^2+8x+1
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Max occures when x = -b/(2a) = -8/(2*-1) = 4
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Max y-value = f(4) = -4^2+8*4+1 = -16 + 32 + 1 = 17
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Cheers,
Stan H.
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