Answer:
[tex]y=x^{3} -2x^{2} -x+2[/tex]
Step-by-step explanation:
You are given the roots 1, -1, and 2.
From there, you can combine all these factors into:
(x-1)(x+1)(x-2)
You know this because if you set these factors to 0, it will give you the roots 1, -1, and 2.
You can find the answer by multiplying all the factors and you get:
[tex]x^{3} -2x^{2} -x+2[/tex]
Hope I helped :)