LaTeX Wiki
Advertisement

\newenvironment{aMatrix}[1]{\left(\begin{array}{#1}}{\end{array}\right)}

\begin{aMatrix}{cc} 2 & 4 \\ 6 & -90 \end{aMatrix}


Alternatively, one can use the pmatrix, bmatrix, and vmatrix environments of the amsmath package ([as described here]).

Advertisement