SOLUTION: What are the rational zeroes for f(x) = x^3 − 2x^2 − x + 2?

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Question 1154822: What are the rational zeroes for f(x) = x^3 − 2x^2 − x + 2?
Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
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First try all integer divisors of the constant term 2, i.e. +/-1 and +/-2.



Or use the grouping method

x^3 − 2x^2 − x + 2 = (x^3-2x^2) - (x-2) = x^2*(x-2) - (x-2) = (x^2 -1)*(x-2) = (x-1)*(x+1)*(x+2).

All rational zeroes are 1, - 1 and -2.