Answer:
The cubic polynomial would be x^3 - 5x^2 + 2x + 8
Step-by-step explanation:
In order to find this, start with parenthesis for each of the 3 in which we use x and the opposite of the root. This is how we build a polynomial function.
(x - 4)(x + 1)(x - 2)
Now we multiply each together.
(x - 4)(x + 1)(x - 2)
(x^2 - 4x + x - 4)(x - 2)
(x^2 - 3x - 4)(x - 2)
x^3 - 3x^2 - 2x^2 - 4x + 6x + 8
x^3 - 5x^2 + 2x + 8
