I want to have a case equation
without the left curly brace
. I am using
\documentclass[11pt,a4paper]{article}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{amsthm}
\begin{document}
\begin{equation}
\begin{cases}
\frac{I}{Z}=12+\frac{7}{Z}[eV] & ,Z<13 \\
\frac{I}{Z}=9.76+58.8Z^{-1.19}[eV] & ,Z\geq13 \\
\end{cases}
\end{equation}
\end{document}
which is perfect for my case, except for the big, left curly brace!