What is abs(-9)?

Jun 20, 2015

$\left\mid - 9 \right\mid = 9$

Explanation:

If $x > 0$ then $\left\mid x \right\mid = x > 0$

If $x = 0$ then $\left\mid x \right\mid = 0$

If $x < 0$ then $\left\mid x \right\mid = - x > 0$

For all $x$ we have $\left\mid x \right\mid \ge 0$

$\left\mid x \right\mid$ is the 'size' of $x$, regardless of its sign.

Equivalently, it is the distance of $x$ from $0$