Answer
$f(x)=-\frac{7}{144}(x-12)^2+7$.
Work Step by Step
If the vertex of a graph is at (m,n), then the general formula for the quadratic function is $f(x)=a(x-m)^2+n$. The vertex of the graph is at (12,7), hence the quadratic function becomes $f(x)=a(x-12)^2+7$. The point (0,0) is on the graph, hence if we plug in the values we get 0=144a+7. $a=-\frac{7}{144}$, hence $f(x)=-\frac{7}{144}(x-12)^2+7$.
