Real numbers/Modulus/Definition

Modulus of a real number

For a real number ${}x\in \mathbb {R}$, the modulus is defined in the following way.

${}\vert {x}\vert ={\begin{cases}x\,,{\text{ if }}x\geq 0\,,\\-x,\,{\text{ if }}x<0\,.\end{cases}}\,$