You can create an under bracket (underbrace) in LaTeX using the \underbrace command within math mode. You can also add a label to the underbrace using a subscript.
Using \underbrace
The \underbrace command is used to place a brace underneath a mathematical expression.
Here's how to use it:
\documentclass{article}
\usepackage{amsmath}
\begin{document}
\[
\underbrace{a + b + c}
\]
\end{document}This will render an underbrace below the expression a + b + c.
Adding a Label to \underbrace
To add a label below the underbrace, use a subscript after the \underbrace command. According to the reference, this provides a way to "label" the underbrace.
\documentclass{article}
\usepackage{amsmath}
\begin{document}
\[
\underbrace{a + b + c}_{\text{sum}}
\]
\end{document}In this example, \text{sum} is added as a label below the brace. The \text command ensures that "sum" is rendered in normal text font instead of math italic font. You can replace "sum" with any label you want.
Examples and Practical Insights
Here's a table summarizing the usage of \underbrace:
| Command | Description | Example |
|---|---|---|
\underbrace{expression} |
Places an underbrace below the expression. | \underbrace{x + y + z} |
\underbrace{expression}_{label} |
Places an underbrace below the expression with the given label. | \underbrace{x + y + z}_{\text{label}} |
Practical Insights:
- Make sure to enclose your mathematical expression within math mode (e.g.,
\[ ... \],$ ... $). - Use
\text{}for labels that are not single variables to ensure correct formatting. - The underbrace will automatically adjust its size to fit the expression underneath it.
