Answer:
f(x) = x³ + 3x² - 6x - 8
Step-by-step explanation:
given the zeros of a polynomial x = a, x = b, x = c then
(x - a), (x - b), (x - c) are the factors of the polynomial and f(x) is the product of the factors
here x = - 1, x = 2 and x = - 4 are the zeros, hence
(x + 1), (x - 2) and (x + 4) are the factors
f(x) = a(x + 1)(x - 2)(x + 4) ← a is a multiplier
let a = 1, then
f(x) = (x + 1)(x - 2)(x + 4)
= (x² - x - 2)(x + 4)
= x³ - x² - 2x + 4x² - 4x - 8
= x³ + 3x² - 6x - 8
