Question

Use the Factor Theorem to show that (x - 3) is a factor of the polynomial

Answer 1

Answer:

P(3) = 0

Step-by-step explanation:

Factor Theorem is a consequence of Remainder Theorem.

Remainder Theorem states that if polynomial f(x) is divided by a binomial (x - a) then the remainder is f(a).

Factor Theorem states that if f(a) = 0, then the binomial (x - a) is a factor of f(x).

We have the polynomial

$P(x) = x^5-3x^4+5x^3-15x^2-6x+18$

To prove that x-3 is a factor of P, we calculate P(3):

$P(3) = 3^5-3*3^4+5*3^3-15*3^2-6*3+18$

$P(3) = 243-243+135-135-18+18$

$P(3) = 0$

Thus, x-3 is a factor of P(x)