SOLUTION: Find the equation of the quadratic function using the given information. The vertex is (x,y) = (-1,4) and a point on the graph is (x,y) = (4,8) Y= I have tried to figur

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Find the equation of the quadratic function using the given information. The vertex is (x,y) = (-1,4) and a point on the graph is (x,y) = (4,8) Y= I have tried to figur      Log On


   

Question 1084896: Find the equation of the quadratic function using the given information.
The vertex is (x,y) = (-1,4) and a point on the graph is (x,y) = (4,8)
Y=
I have tried to figure this out. I got X squared + 2x-2 but was marked wrong
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
y=a%28x-h%29%5E2%2Bk would have vertex at (h, k).


a%28x-h%29%5E2%2Bk=y
a%28x-h%29%5E2=y-k
a=%28y-k%29%2F%28x-h%29%5E2, a symbolic solution for factor, a.

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Using given vertex and other point on the graph,
a=%288-4%29%2F%284-%28-1%29%29%5E2
a=4%2F%285%29%5E2
a=4%2F25
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highlight%28y=%284%2F25%29%28x%2B1%29%5E2%2B4%29