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Homework Help: How to find the equation of a parabola with the following vertex.

  1. Feb 11, 2009 #1
    1. I need to find the equation of a parabola with a vertex of (-3,-2). It has to open down.



    2. I understand of hopefully will understand it.



    3. My answer was y=-3x Squared -3x-2 Which I found to be wrong.
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Feb 12, 2009 #2

    tiny-tim

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    Homework Helper

    Welcome to PF!

    Hi Cobalt! Welcome to PF! :smile:
    yes, it goes through (-3,-2) …

    but it's -3(x + 0.5)2 + something. :wink:
     
  4. Feb 12, 2009 #3

    HallsofIvy

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    A parabola with vertex at (x0, y0) is given by
    y= a(x- x0)2+ y0. If opens downward, then a must be negative.
     
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