Q:

Yasnippet including backslash

I would like to use Yasnippet to insert the template for a latex inline equation: \( \) 
The snippet is defined:
    # -*- Mode: snippet -*-
# name: inline equation
# key: ineq
# --
\(  \)

But Yasnippet inserts only the parentheses ( ) without the backslashes. Any suggestions?

A:

The backslash is used in regular expressions to escape individual characters:

For the most part, \ followed by any character matches only that character.

So \( gives you ( in your output.  To get the backslash in the output, escape it:
\\( \\)

