Write the Absolute Value as Piecewise |a|

$| a |$

Step 1

To find the interval for the first piece, find where the inside of the absolute value is non-negative.

$a \geq 0$

Step 2

In the piece where $a$ is non-negative, remove the absolute value.

$a$

Step 3

To find the interval for the second piece, find where the inside of the absolute value is negative.

$a < 0$

Step 4

In the piece where $a$ is negative, remove the absolute value and multiply by $- 1$ .

$- a$

Step 5

Write as a piecewise.

${\begin{cases} a & a \geq 0 \\ - a & a < 0 \end{cases}$