Re: HSC 2015 4U Marathon
$ Since $P(x)=x^3+x+1$ is an increasing function over the reals, this means that only one root of $P(x)$ exists. Note that $P(-1)\,<\,0\,<\,P(0)$, so our root must lie in the open interval $(-1, 0)$. But by the rational root theorem, there exists no such ordered pair...