[edit] amsmath matrix environments

The amsmath package provides commands to typeset matrices with different delimiters. Once you have loaded \usepackage{amsmath} in your preamble, you can use the following environments in your math environments:

If you need to create matrices with different delimiters, you can add them manually to a plain matrix. For example:

[edit] Inline matrices

When typesetting inline math, the usual matrix environments above may look too big. It may be better to use smallmatrix in such situations, although you will need to provide your own delimiters.

Trying to typeset an inline matrix here
$\begin{pmatrix}
  a & b\\ 
  c & d
\end{pmatrix}$ 
but it looks too big, so let's try 
$\big(\begin{smallmatrix}
  a & b\\
  c & d
\end{smallmatrix}\big)$ 
instead.

The mathtools package provides psmallmatrix, bsmallmatrix etc environments for convenience.

[edit] Further reading

• Mathematical expressions
• Brackets_and_Parentheses
• Aligning equations with amsmath
• Display style in math mode
• The not so short introduction to LaTeX2ε
• amsmath package documentation
• mathtools package documentation