SOLUTION: What is the equation written in vertex form of a parabola with a vertex of (9, -1) that passes through (7, 7)?

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Question 1170036: What is the equation written in vertex form of a parabola with a vertex of (9, -1) that passes through (7, 7)?
Found 2 solutions by Boreal, MathTherapy:
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
y=a(x-h)^2+k
=a(x-9)^2-1, change sign of x and keep sign of y
when x=7 y=7
so 7=a(-2)^2-1=4a-1
so a=2
answer is y=2(x-9)^2-1
graph%28300%2C300%2C-10%2C20%2C-10%2C200%2C2%28x-9%29%5E2-1%29
graph%28300%2C300%2C3%2C12%2C-10%2C10%2C7%2C2%28x-9%29%5E2-1%29

Answer by MathTherapy(10553) About Me  (Show Source):
You can put this solution on YOUR website!

What is the equation written in vertex form of a parabola with a vertex of (9, -1) that passes through (7, 7)?
Vertex form of a parabola: matrix%281%2C3%2C+y%2C+%22=%22%2C+a%28x+-+h%29%5E2+%2B+k%29

matrix%281%2C3%2C+7%2C+%22=%22%2C+a%287+-+9%29%5E2+%2B+-+1%29 ---- Substituting (7, 7) for (x, y), and (9, - 1) for (h, k)



highlight_green%28matrix%281%2C3%2C+y%2C+%22=%22%2C+2%28x+-+9%29%5E2+-+1%29%29 ---- Substituting 2 for a, and (9, - 1) for (h, k)