Absolute value

The graph of the absolute value function for real numbers.

In mathematics, the absolute value of a number is the number without the sign. The absolute value of 2 is 2, the absolute value of -2 is also 2. This notation is to express a numbers distance from zero on a number line. The absolute value of 10 would be 10 since the number 10 is 10 numbers away from zero, same follows with negatives.

$\begin{cases} \ \;\,\ \ x &\mathrm{if}\ x \ge 0\\ \ \;\, - x &\mathrm{otherwise} \end{cases}$

For real numbers, the absolute value of a is denoted by | a | (a vertical bar on each side of the quantity) .