SOLUTION: 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

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: 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      Log On


   



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) About Me  (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)