Question

use remainder theorem to factorise the following expression complety. 2x^3-x^2-5x-2.​

Answer 1

By remainder theorem we know that when a polynomial f (x) is divided by x - a, then the remainder is f(a).

Let f(x) = 2x3 + 3x2 − 5x − 6

f (−1) = 2(−1)3 + 3(−1)2 − 5(−1) − 6 = −2 + 3 + 5 − 6 = 0

Thus, (x + 1) is a factor of the polynomial f(x).