Question

\(x^2+\left|x\right|-2=0\)

Giải pt

Answer 1

\(x^2+\left|x\right|-2=0\Leftrightarrow\left(\left|x\right|+2\right)\left(\left|x\right|-1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}\left|x\right|+2=0\\\left|x\right|-1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}\left|x\right|=-2\left(L\right)\\\left|x\right|=1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-1\end{matrix}\right.\)

Vậy PT có nghiệm \(x=\pm1\)