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| Question 257655:  a Parabola has a vertex (-1,5) and contains the point (2,-4). Write an equation of the parabola in the form y-k = a(x-h)^2
 Answer by nerdybill(7384)
      (Show Source): 
You can put this solution on YOUR website! a Parabola has a vertex (-1,5) and contains the point (2,-4). Write an equation of the parabola in the form y-k = a(x-h)^2 .
 y-k = a(x-h)^2
 The (h,k) is the vertex
 .
 Plug in what was given in the problem:
 y-k = a(x-h)^2
 -4-5 = a(2-(-1))^2
 -9 = a(2+1)^2
 -9 = a(3)^2
 -9 = a(9)
 -1 = a
 .
 So, we can rewrite:
 y-k = a(x-h)^2
 as
 y-5 = -1(x-(-1))^2
 y-5 = -(x+1)^2  (this is what they're looking for)
 
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