The positive integers $ \alpha, \beta, \gamma$ are the roots of a polynomial $ f(x)$ with degree $ 4$ and the coefficient of the first term is $ 1$. If there exists an integer such that $ f(-1)=f^2(s)$. Prove that $ \alpha\beta$ is not a perfect square.
Problem
Source: China TST 2002 Quiz
Tags: algebra, polynomial, number theory unsolved, number theory