This code:
\documentclass[12pt]{article}
\begin{document}
\begin{equation}\label{eq:test}
\begin{array}{l}
\left[ \displaystyle \frac{e^{ix}}{2} = \\
= \sin (x) + \cos (x) \right]
\end{array}
\end{equation}
\end{document}
generates an error:
Missing \right. inserted. \left[ \displaystyle \frac{e^{ix}}{2} = \\
Extra \right. = \sin (x) + \cos (x) \right]
If I modify it as
\documentclass[12pt]{article}
\begin{document}
\begin{equation}\label{eq:test}
\begin{array}{l}
\left[ \displaystyle \frac{e^{ix}}{2} = \right. \\
= \left. \sin (x) + \cos (x) \right]
\end{array}
\end{equation}
\end{document}
it can be built, but the closing square bracket \right] appears smaller than the opening \left[. I would like to have them instead of the same dimensions (as \left[).
Is it possible? How?
\biggl[and\biggr]. – Ian Thompson Jun 13 '19 at 16:10arrayfor displayed equations use an amsmath alignment such asalignor ``aligned` they use display style – David Carlisle Jun 13 '19 at 16:13