3.13.2 Greatest hits from previous weeks

Greatest hits from previous weeks:

3.13.2.1 How to write an ma^..\211n matrix in LaTeX?

http://tex.stackexchange.com/questions/69997/how-to-write-an-m%e2%a8%89n-matrix-in-latex

I tried using the below code but it works only for 2a^..\2112 matrix. 
\[ 
M= 
\left[ {\begin{array}{cc} 
1 & 2 \\ 
3 & 4 \\ 
\end{array} } \right] 
\] 
Now the following doesn't work for  ...
 

- asked by Vutukuri (20 votes), answered by David (20 votes)

3.13.2.2 What is the LaTeX command for "em dash" (a^\200\224)?

http://tex.stackexchange.com/questions/53413/what-is-the-latex-command-for-em-dash

I am trying to insert the symbol in the title of the question, which I copied from a PDF article, but it appears as space in the output file. What is the corresponding LaTeX command?
 

- asked by Tarek (132 votes), answered by Keks Dose (135 votes)