Answer: -2, 0, 4
Set the equation equal to zero.
x³ - 2x² - 8x = 0
Factor out x in the equation, since all the terms (x³, -2x², and -8x) are divisible by x. You can check your accuracy using the Distributive Property.
x(x² - 2x - 8) = 0
Factor out the polynomial. To do this, find two numbers that multiply to get the last term, -8, and add together to get the middle term, -2. In this case, those two numbers are -4 and 2 (-4 × 2 = -8 and -4 + 2 = -2). Don't forget about the x that was factored out before!
x(x - 4)(x + 2) = 0
Set each factor equal to zero and solve for x. The factors in the equation are x, (x - 4), and (x + 2).
x = 4
x = -2
The zeros of the polynomial function are -2, 0, and 4.