Finding parabola equation and only given a graph

[stuffradio]

1. The problem statement, all variables and given/known data

The math problem I am supposed to do is, find an equation for the given graph.

2. Relevant equations
There are no equations given, but here's an image for it.
http://i51.tinypic.com/24gne5i.png


3. The attempt at a solution
I understand there is an equation like
y=ax^2+bx+c but I'm not sure how I can apply it to this graph. I know the Vertex of the Parabola is (0,5) and the line of symmetry I think it's called is x=0, but what I'm confused at is what the actual equation would be.

If anyone can give me a clue as how I can solve it, that would be great!

[Kevin_Axion]

Put it in vertex form y = a(x + h)^2 + k where h is the x value of the vertex and k is the y value. The answer should then be y = ax^2 + 5, you can solve for a by plugging in values of x, y and then isolate a, there is a clear one (1, 4). I don't know if I can give this much information though.

[stuffradio]

Wow, I'm impressed this was answered so quickly! Thanks!
So is this a standard equation that can be used for solving all parabola's?

[HallsofIvy]

Wow, I'm impressed this was answered so quickly! Thanks!
So is this a standard equation that can be used for solving all parabola's?
Especially at 1 AM!:wink:

Yes, that formula is true for all parabolas with vertical axis.