# Problem with defining parenthesis command in Texmaker

I am new to LaTeX and have been trying to redefine the \left( command to become $$. for some reason TeXmaker won't let me do this, it keeps telling me that \( is already defined but then when I type \( in math mode it has a fit. What should I do? Here is my preamble:  \documentclass[12pt]{article} \setlength\parindent{0pt} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} % input encoding UTF-8 \usepackage{amsmath,amssymb,amsthm} \usepackage{color} \usepackage[margin=3.0cm]{geometry} \usepackage{graphicx} \usepackage{float} \usepackage{array} \usepackage{url} % % \newcommand{\D}{\partial} %partial operator  • I suggest you not to redefine \left. Use the Find/Replace technique. Mar 23 '14 at 17:45 • You certainly do not want to redefine \left( by \(; the former can only occur in math mode, whereas the latter marks the start of inline math mode. Did you mean ( instead? Mar 23 '14 at 17:49 • I basically want to be able to get a \left( by typing something short. \( seemed like the natural choice. @Sigur good suggestion, thanks. Mar 23 '14 at 18:14 • @user27182, \($$ is the same as , it is the way to change from text mode to math mode. Mar 23 '14 at 18:21
• @Sigur Almost the same :) Mar 23 '14 at 18:38

You can overwrite LaTeX's internal definitions easily enough. It really isn't a good idea, though.

\documentclass{article}
\begin{document}
$$$\frac{a}{b}$$$
\end{document}


It would be better to use something like \lp and \rp.

\documentclass{article}
\newcommand\lp{\left(}
\newcommand\rp{\right)}
\begin{document}
$\lp \frac{a}{b} \rp$
\end{document}