Determine the quadratic function whose graph is given

Hi All,

I would really appreciate some help/hints for the following problem I am stuck on.

Determine the quadratic function whose graph is given:

The function has given points at (-1,5), (3,5), and y-intercept at (0,-1)

I know that the axis of symmetry (h) is at 1 because it is the mid-point between -1 and 3. If I plug that into the function a(x-h)^2 + k, I still have two unknowns, a and k

a(x-1)^2+k

Can someone please explain to me how to solve this. Thank you very much in advance.

Alex

Re: Determine the quadratic function whose graph is given

Let:

$\displaystyle f(x)=ax^2+bx+c$ and use the given points to state:

$\displaystyle f(-1)=5$

$\displaystyle f(0)=-1$

$\displaystyle f(3)=5$

The second equation tells you $\displaystyle c=-1$, and this along with the first and third equations will give you two equations and two unknowns.