When looking at the rational function f of x equals the quantity x minus one times the quantity x plus two times the quantity x plus four all divided by the quantity x plus one times the quantity x minus two times the quantity x minus four , sue and ed have two different thoughts. sue says that the graph of the function has zeros at x = −1, x = 2, and x = 4. ed says that the function is undefined at those x values and discontinuities are created in the graph . who is correct? justify your reasoning by explaining the difference between zeros and discontinuities.