How to find focus of parabola?

Question

if the equation is x^2=16y and vertex is (0,-3).

Answer 1

The equation of the parabola x² = 16y

                                                     x² = 4(4) y

The equation of parabola formula : x² = 4ay

                                                                a = 4

        The vertex is (0, -3)

The focus is (0, a) = (0, 4).