# Why don't the following math delimiters work on the site $$$? I was wondering why \( and \[ math delimiters dont work or are not allowed on the site? I know they are capable of working in MathJax since I have used them on other forums. Would it be possible to have these delimiters operational? Linked is the documentation on setting \( and \[ as delimiters. ## 1 Answer Those delimiters are operational, but not exactly in the form you expect. Look at the source code of this page: inlineMath: [ ["", ""], ["\\$","\\$"] ], displayMath: [ ["",""], ["\\[", "\$"] ]  So, \$y=x^2\$ produces $y=x^2$ And \\$y=x^2\$/extract_itex] will produce $y=x^2$, though one has to be masochistic to actually use this feature. The reason for repeated backslashes is Markdown syntax: The reason that \(...$$ are not used on the SE sites is that Markdown uses the backslash as an escape character to prevent the special meaning of the characters that follow. So one could use \[...$ to prevent the brackets from indicating a link, for example. This conflicts with using the LaTeX delimiters $$...$$ for in-line math and $...$ for display math. So they have used the Plain TeX delimiters: $...$ and $$...$$ instead. -- Davide Cervone

I don't know why the round parentheses require quadruple backslash instead of double... but I suppose this does not matter much, as few people would want to use this syntax with double backslashes, either.

It seems that back in 2011, $y=x^2$ was operational: see Math typesetting using  instead of the dollars.

• Ok thanks. I just asked because I noticed that I started to get into the habit of using TeX delimiters in my LaTeX documents. – dustin Dec 13 '14 at 2:32
• More precisely, what's happening is that \ is an escape character in both Markdown and JavaScript. So the JS string literal "\\[" in the MathJax config actually defines \[, with just one backslash, as a math delimiter -- but in Markdown, outside code blocks, you have to type \\[ to actually produce the output \[ instead of just [. (As for why parentheses are configured to need even more backslashes, I have no idea. It might be a bug in the MathJax config.) – Ilmari Karonen Dec 13 '14 at 19:05
• Davide Cervone confirmed that the quadruple backslash is over-escaping. I will update this post if/when it gets fixed. – user147263 Dec 15 '14 at 0:12