SOLUTION: find the maximum value of y=-x^2 + 6x

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Question 56717This question is from textbook
: find the maximum value of y=-x^2 + 6x This question is from textbook

Found 2 solutions by funmath, stanbon:
Answer by funmath(2933) About Me  (Show Source):
You can put this solution on YOUR website!
find the maximum value of y=-x%5E2%2B6x
The maximum value of a parabola, whose coefficient of x^2 is negative, is it's vertex.
This quadratic equation is in standard for:highlight%28y=ax%5E2%2Bbx%2Bc%29, our a=-1, b=6, and c=0.
The equation for finding the x value of a quadratic equation written in standard form is: highlight%28x=-b%2F2a%29
x=-%286%29%2F%282%28-1%29%29
x=-6%2F-2
x=3
Plug that into the parabola for x and you'll find the maximum value.
y=-%283%29%5E2%2B6%283%29
y=-9%2B18
y=9
The maximum value of this parabola is at (3,9).
Happy Calculating!!!

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
maximum value of y=-x^2 + 6x
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you have a quadratic with a=-1, b=6
the max is at x=-b/2a = -6/-2=3
Then f(3)=-(3)^2+6(3)=27
So the max is at (3,27)
Cheers,
Stan H.