5.41.2 Greatest hits from previous weeks

5.41.2.1 How can I split an equation over two (or more) lines

https://tex.stackexchange.com/landing/r/digest?cta=question&id=3782

I am having the following equation: 
\begin{equation} 
Q(\lambda,\hat{\lambda}) = -\frac{1}{2} P(O \mid \lambda ) \sum_s \sum_m \sum_t \gamma_m^{(s)} (t) \left( n \log(2 \pi ) + \log \left| C_m^{(s)}  ... 
[math-mode] [equations] [line-breaking] [breqn]
 

asked by Peter Smit https://tex.stackexchange.com/landing/r/digest?cta=user&id=459 240 votes

answered by Will Robertson https://tex.stackexchange.com/landing/r/digest?cta=user&id=179 166 votes

5.41.2.2 How to change certain pages into landscape/portrait mode

https://tex.stackexchange.com/landing/r/digest?cta=question&id=337

How can I change some pages into document into landscape mode, while leaving the others in portrait mode (or vice versa)? 
[landscape]
 

asked by hayalci https://tex.stackexchange.com/landing/r/digest?cta=user&id=183 297 votes

answered by rcs https://tex.stackexchange.com/landing/r/digest?cta=user&id=118 313 votes

5.41.2.3 How to type special/accented letters in LaTeX?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=8857

How to type these special letters from European languages in latex? 
A~\[Currency], A~(c), and L'? 
[symbols] [languages] [characters] [accents]
 

asked by user2918 https://tex.stackexchange.com/landing/r/digest?cta=user&id=2918 181 votes

answered by Kit https://tex.stackexchange.com/landing/r/digest?cta=user&id=791 149 votes

5.41.2.4 Why do the less than symbol (<) and the greater than symbol (>) appear wrong as upside down exclamation (A^\[DownExclamation]) or question mark (A^\[DownQuestion])?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=2369

When typing < or > in LaTeX and compiling with pdflatex, the less than and greater than symbols appear at upside down exclamation points. I'm not in math mode. 
[symbols] [punctuation] [font-encodings]
 

asked by biased_estimator https://tex.stackexchange.com/landing/r/digest?cta=user&id=996 256 votes

answered by Stefan Kottwitz https://tex.stackexchange.com/landing/r/digest?cta=user&id=213 225 votes

5.41.2.5 Nice scientific pictures show off

https://tex.stackexchange.com/landing/r/digest?cta=question&id=158668

Task 
Show off your best scientific illustration ! 
The main purpose of this question is to share beautiful scientific pictures, preferably with an educational aspect. 
Content 
Your post must  ... 
[diagrams] [3d] [technical-drawing] [fun] [big-list]
 

asked by Thomas https://tex.stackexchange.com/landing/r/digest?cta=user&id=42660 501 votes

answered by Charles Staats https://tex.stackexchange.com/landing/r/digest?cta=user&id=484 298 votes

5.41.2.6 Omitting the date when using \maketitle

https://tex.stackexchange.com/landing/r/digest?cta=question&id=2760

I'm using the \author and \title commands to produce a title with \maketitle. I also know that there is a \date command to specify the date of my work. However, if I omit \date, \maketitle will  ... 
[titles] [datetime]
 

asked by lockstep https://tex.stackexchange.com/landing/r/digest?cta=user&id=510 269 votes

answered by frabjous https://tex.stackexchange.com/landing/r/digest?cta=user&id=411 248 votes

5.41.2.7 Align equation left

https://tex.stackexchange.com/landing/r/digest?cta=question&id=145657

Here is my split equation: 
\documentclass{article} 
\usepackage{amsmath} 
\begin{document} 
\begin{equation} 
\begin{split} 
a_{ijk} =& \frac {Pr(M_{I} =2  \&  M_J=1 \& M_K =1 | I=i , J=j ,  ... 
[equations] [align]
 

asked by user35571 https://tex.stackexchange.com/landing/r/digest?cta=user&id=35571 57 votes

answered by Ludovic C. https://tex.stackexchange.com/landing/r/digest?cta=user&id=31058 59 votes