So your equation is in the form (y-k)^2 = 4p(x-h), where focus is at (h+p,k) and vertex is at (h,k) If h = 4 from the vertex and h + p = 3 from the focus, p = -1 in your parabola. So your equation looks like (y--7)^2 = -4(x - 4). Clean that up and you're all set.