# Giving two matrices the same width

I've got two matrices, were one is an ordered pair (a point) and the second one is a rotation matrix below that. How do I get them both to be the same width? I have two sets of parentheses and I still want them to be separate arrays.

\documentclass[12pt]{article}
\usepackage{a4wide}
\usepackage{amsmath}

\begin{document}
$$\left( \begin{array}{ccc} 2 & , & 3 \end{array} \right) \left[ \begin{array}{ccc} \cos{\theta} & -\sin{\theta} \\ \sin{\theta} & \cos{\theta} \end{array} \right]$$
\end{document}


Note that $$...$$ shouldn't be used in LaTeX, see Why is $...$ preferable to $$...$$?; also a4wide is a deprecated package. If you want to widen the text area, use geometry.

You can obtain what you want with blkarray:

\documentclass[12pt]{article}
\usepackage{amsmath,blkarray}

\begin{document}
$\begin{blockarray}{cc} \begin{block}{(c@{\rlap{,}}c)} 2 & 3 \\ \end{block} \begin{block}{[cc]} \cos\theta & -\sin\theta \\ \sin\theta & \cos\theta \\ \end{block} \end{blockarray}$
\end{document}


If you want to distance the two blocks, add a phantom row and some vertical negative space:

\documentclass[12pt]{article}
\usepackage{amsmath,blkarray}

\begin{document}
$\begin{blockarray}{cc} \begin{block}{(c@{\rlap{,}}c)} 2 & 3 \\ \end{block} & \\[-2ex] \begin{block}{[cc]} \cos\theta & -\sin\theta \\ \sin\theta & \cos\theta \\ \end{block} \end{blockarray}$
\end{document}


Matrices are better typeset with the environments provided by amsmath, rather than directly with array.

\documentclass[12pt]{article}
\usepackage{amsmath,mathtools,calc}

\begin{document}
$\begin{pmatrix} \mathmakebox[\widthof{\cos\theta}]{2}\mathrlap{\ \ ,}& \mathmakebox[\widthof{-\sin\theta}]{3} \end{pmatrix} \begin{bmatrix} \cos\theta & -\sin\theta \\ \sin\theta & \cos\theta \end{bmatrix}$
$\begin{bmatrix} 2 & 3 \end{bmatrix} \begin{bmatrix} \cos\theta & -\sin\theta \\ \sin\theta & \cos\theta \end{bmatrix}$
\end{document}


• 1) It's not a vector it's an ordered pair. 2) Sorry 3) I want the ordered pair above the matrix. – theStandard Apr 4 '14 at 9:35
• @user2342771 I did see the original comment; please, never do that again. Sorry for having misunderstood your request, now the answer should have what you're looking for. Still, I can't understand what the thing should mean. – egreg Apr 4 '14 at 9:55
• That was a joke that my friend put in. I tried to add a new line to the comment and didn't realize it would actually submit the comment. – theStandard Apr 7 '14 at 4:41
\documentclass[12pt]{article}

\begin{document}
$\begin{array}{r @{} c @{} l} ( & 2 \quad,\quad3 & )\\ \Bigg[ & \begin{array}{cr} \cos\theta & -\sin\theta \\ \sin\theta & \cos\theta \\ \end{array} & \Bigg] \end{array}$
\end{document}