# If a polynomial function f(x) has roots –9 and 7 – i, what must be the factors of f(x)?

A polynomial is a type of expression. Before we discuss polynomials, we should know about expressions.

## Answer: If a polynomial function f(x) has roots -9 and (7 – i), then (x + 9) and (x + i - 7) are the factors of f(x).

Let's see in detail.

**Explanation:**

Given,

The roots of the polynomial function f(x) are -9, and (7 – i)

Therefore x = -9, and x = 7 - i

⇒ x + 9 = 0 and x - 7 + i = 0

So, (x + 9) and (x + i - 7) must be the factors of f(x).