I am new to TeX and I am trying to write the following
\begin{equation}
N_{a,0}\begin{cases}
R_{0,0} & a=0\\
N_{a-1,0}e^{-m} & 1\leq a\leq a_{max}-1\\
N_{a-1,0}e^{-m}/1-e^{-m} & a=a_{max}
\end{cases}
\end{equation}
but I get an error because &
is not being recognized as a command, it does not even have the green color as the rest of the commands do. Any ideas on how to fix it?
\usepackage{amsmath}
in your document?