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Homework Help: Let f(x)=3x^2+6x-10 . For which input x is the value of the function a minimum?

  1. Sep 30, 2011 #1
    And what is the minimum value?
    ( -b/2a is for a maximum problem, but how do you get through this kind of problem?)
     
  2. jcsd
  3. Sep 30, 2011 #2

    rock.freak667

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    x=-b/2a will give you the stationary point for the quadratic. In f(x) =ax^2+bx+c, if a>0 is the stationary point maximum or minimum?
     
  4. Sep 30, 2011 #3

    SammyS

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    For the quadratic, ax2 + bx + c:

    If the coefficient of x2, which is a, is negative, then x = -b/2a, gives the x coordinate of the maximum.

    If the coefficient of x2, which is a, is positive, then x = -b/2a, gives the x coordinate of the minimum.
     
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