Answer: f(x) = (x - 8)^2 - 6
The equations are written in vertex form, so we can tell the point of the vertex from each equation.
Vertex form is y = a( x - h)^2 + k
Where (h,k) is the vertex
From looking at the graph, we know the vertex will have a positive x value, and a negative y value.
So h will be positive, and k will be negative.
f(x) = (x-8)^2 - 6 is the only answer choice with a positive h and a negative k.
I attached a photo to better show what vertex form is.