We can check our answer by substituting the given zeros for x. If the result is y=0, it means that the given numbers are actually zeros of the function and our answer is correct. Let's start by checking - 1.
y=x^3-x^2-2x
y=( - 1)^3-( - 1)^2-2( - 1)
y=0 ✓
We proved that - 1 is a zero of the function. Let's now check 0 .
y=x^3-x^2-2x
y= 0^3- 0^2-2( 0)
y=0 ✓
We have shown that 0 is also a zero. Finally, let's see what happens with 2.
y=x^3-x^2-2x
y= 2^3- 2^2-2( 2)
y=0 ✓
We found that 2 is also a zero. Since - 1, 0, and 2 are zeros of the polynomial function, our answer is correct.