Chắc là giải nghiệm nguyên?
\(\Leftrightarrow y^2=x^4+x^2+1\)
Ta có \(\left\{{}\begin{matrix}x^4+x^2+1\ge x^4=\left(x^2\right)^2\\x^4+x^2+1\le x^4+2x^2+1=\left(x^2+1\right)^2\end{matrix}\right.\)
\(\Rightarrow\left(x^2\right)^2< y^2\le\left(x^2+1\right)^2\)
\(\Rightarrow y=\pm\left(x^2+1\right)\)
\(\Rightarrow\left(x^2+1\right)^2=x^4+x^2+1\)
\(\Rightarrow x=0\Rightarrow y=\pm1\)