Question

A polynomial function has roots -5 and 1. Which

of the following could represent this function?
f(x) = (x + 5)(x + 1)
f(x) = (x - 5)(x - 1)
f(x) = (x - 5)(x + 1)
f(x) = (x + 5Yx - 1)

Answer 1

f(x) = (x + 5)(x - 1)

Explanation:

f(x) = (x + 5)(x - 1) has the roots of -5 and 1, when you set each factor equal to zero.

x + 5 = 0

x = -5

So, -5 is a root of the function.

x - 1 = 0

x = 1

So, 1 is the other root of the function.

f(x) = (x + 5)(x - 1) is the polynomial function with the roots of -5 and 1