Which of the following statements must be true about the polynomial function f(x)? If 1+ the sqrt of 13 is a root of f(x), then -1- the sqrt of 13 is also a root of f(x). If 1 + 13i is a root of f(x), then 1 – 13i is also a root of f(x). If 13 is a root of f(x), then –13 is also a root of f(x). If –13 + i is a root of f(x), then 13 + i is also a root of f(x).