SOLUTION: The function f (x) = 2x2 + 8x + c has a minimum value of −11.Find the value of c

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Question 408852: The function f (x) = 2x2 + 8x + c has a minimum value of −11.Find the value of
c

Answer by lwsshak3(11628) About Me  (Show Source):
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The function f(x) = 2x^2+8x+c has a minimum value of −11.Find the value of c
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Standard form of parabola: y=(x-h)^2+k with (h,k) being the (x,y) coordinates of the vertex.
completing the square:
y=2(x^2+4x+4)-8+c
y=(x+2)^2-8+c
This is a parabola that opens upwards (so it has a minimum) with a minimum at -8+c which is equal to -11 as given.
-8+c=-11
c=-3
equation of parabola:
ans:2x^2+8x-3
se graph below
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+graph%28+300%2C+300%2C+-10%2C+10%2C+-15%2C+10%2C+2x%5E2%2B8x-3%29+