Focus is above vertex, so parabola is opening upwards.
Distance between vertex and focus is 2, which is -p, so p = -2.
Since this is a vertical graph the equation will be of the form (x-h)^2 = 4p(y-k), where (h,k) is the vertex (4,3),
so the equation is:
(x-4)^2 = -8(y-3)