Which is the graph of the function f f(x)=(x-4)(x+4)?

Answer:
4th bubble
Step-by-step explanation:
First FOIL: f(x) = x² + 3x - 4. Then convert from Standard Form [y = Ax² + Bx + C] to Vertex Form [y = A(X - H)² + K], where (h, k) is the vertex and -h gives the OPPOSITE terms of what they really are. So, you do this by completing the square [½B]²:
Remember, -h gives the OPPOSITE terms of what they really are, so your vertex is (-1½, -6¼).
If you are ever in need of assistance, do not hesitate to let me know by subscribing to my channel [USERNAME: MATHEMATICS WIZARD], and as always, I am joyous to assist anyone at any time.