Answer
$$\frac{-1}{4}*(y-4)^2 = x-4$$
Work Step by Step
The graph is going to be of the form $$a(y-4)^2 = x-4$$
Since there is a vertex at $(4,4)$. Also, the graph passes through the origin. We plug that in...
$$a(0-4)^2 = 0-4$$
$$16a = -4$$
$$a = -1/4$$
Thus the answer is,
$$-1/4(y-4)^2 = x-4$$
