Question

How do you use the factor theorem to determine whether x-1 is a factor of `f(x)=x^3+4x-5`?

Answer 1

Calculate `f(1)`.

Explanation:

If `f(1) = 0`, then `x - 1` is a factor of `f`. So let's calculate `f(1)`.

`f(1) = 1 + 4 - 5 = 5 - 5 = 0`. So `1` is a root of this polynomial, and `x - 1` is a factor of it.