\(x^3=x\Rightarrow x^3-x=0\)
\(\Rightarrow x\left(x^2-1\right)=0\)\(\Rightarrow\left[\begin{matrix}x=0\\x^2-1=0\end{matrix}\right.\)
\(\Rightarrow\left[\begin{matrix}x=0\\x^2=1\end{matrix}\right.\)\(\Rightarrow\left[\begin{matrix}x=0\\x=\pm1\end{matrix}\right.\)
x3 = x
\(\Rightarrow\) x3 - x = 0
\(\Rightarrow\) x . x2 - x . 1 = 0
\(\Rightarrow\) x(x2 - 1) = 0
\(\Rightarrow\) \(\left[\begin{matrix}x=0\\x^2-1=0\end{matrix}\right.\) \(\Rightarrow\left[\begin{matrix}x=0\\x^2=0+1\end{matrix}\right.\) \(\Rightarrow\left[\begin{matrix}x=0\\x^2=1\end{matrix}\right.\) \(\Rightarrow\left[\begin{matrix}x=0\\x^2=1^2\end{matrix}\right.\) \(\Rightarrow\left[\begin{matrix}x=0\\x=1\end{matrix}\right.\)
Vậy: x \(\in\) {0; 1}
