I have one instance of cases within the align environment, as follows:
\documentclass[a4paper]{article}
\usepackage{amsmath}
\begin{document}
\begin{align}
f(x) &=1x \\
g(x) &=\begin{cases}
2 x \label{eq:g_1} \\
3 x
\end{cases}
\end{align}
\end{document}
which produces:
How can I number the different cases separately, thus having the numbering (1) for the first equation, (2a) and (2b) for the two cases?
Adding a second label within cases as follows
\documentclass[a4paper]{article}
\usepackage{amsmath}
\begin{document}
\begin{align}
f(x) &=1x \\
g(x) &=\begin{cases}
2 x \label{eq:g_1} \\
3 x \label{eq:g_2}
\end{cases}
\end{align}
\end{document}
produces the amsmath package error: multiple \label's.
Of course a solution with array instead of cases, or any other alternative, works as well.
Thank you in advance for your help, Basi.
