How do I find f(x) and a, of this derivative limit

Question

The question says "The limit below represents a derivative of f'(a). Find f(x) and a.

The problem it gives me is lim (h->0) ((2+h)^4-16)/h.

Answer 1

f(x) = x⁴ and a = 2 (so f(2) = 16)