1
$f(x)=\frac{\left| x \right|}{x}+x$
✓
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2
$f(x)=۲-\left| x-۱ \right|$
✓
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3
$f(x)=۲x-\left| x-۱ \right|$
✓
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4
$f(x)=\left\{ \begin{matrix} {{x}^{۲}} \\ {{x}^{۲}}-۱ \\\end{matrix}\,\,\,\,\,\,\,\,\begin{matrix} x\le ۰ \\ x \gt ۱ \\\end{matrix} \right.$
✓
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