kristysturk62 kristysturk62 30-11-2020 Mathematics contestada If –1 is a root of f(x), which of the following must be true? A factor of f(x) is (x – 1). A factor of f(x) is (x + 1). Both (x – 1) and (x + 1) are factors of f(x). Neither (x – 1) nor (x + 1) is a factor of f(x).