Piecewise Functions

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# Basic Commands

The `array` command in combination with the `\left` and `\right` commands provides an easy way to typeset piecewise-defined functions. Here is some sample code followed by the output:

```
$$
f(x) = \left\{
\begin{array}{ll}
-x & \quad x \leq 0 \\
x & \quad x > 0
\end{array}
\right.
$$
```

The result is:(1)

\begin{align} f(x) = \left\{ \begin{array}{ll} -x & \quad x \leq 0 \\ x & \quad x > 0 \end{array} \right. \end{align}

The arguments to the *array* command are `ll`, indicating two cells that are left-aligned. Other options here include `c`, for center-aligned, and `r` for right-aligned. The `\quad` command adds in some additional spacing between the definition and the inequalities.

page revision: 3, last edited: 06 Nov 2010 12:31