For y=a(x−h)2+ky = a(x-h)^2 + ky=a(x−h)2+k, vertex is (h,k)(h,k)(h,k); for x=a(y−k)2+hx = a(y-k)^2 + hx=a(y−k)2+h, vertex is (h,k)(h,k)(h,k).
