9.25.2 Greatest hits from previous weeks

9.25.2.1 How to write two dot above a letter?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=152951

the two dots above a letter represents two derivative of varible t. 
My method: 
\documentclass[UTF8]{ctexart} 
\usepackage{amsmath} 
\usepackage{amssymb} 
\usepackage{graphicx} 
\usepackage{epstopdf} 
\... 
[math-mode] [accents]
 

asked by mma https://tex.stackexchange.com/landing/r/digest?cta=user&id=43727 Score of 138

answered by Cain https://tex.stackexchange.com/landing/r/digest?cta=user&id=28428 Score of 190

9.25.2.2 bibtex vs. biber and biblatex vs. natbib

https://tex.stackexchange.com/landing/r/digest?cta=question&id=25701

I've heard of many different bibliography-related packages/platforms/?. What's the difference between the following, which is good for what tasks, advantages/disadvantages, which one is the most ... 
[bibliographies] [biblatex] [bibtex] [natbib] [biber]
 

asked by doncherry https://tex.stackexchange.com/landing/r/digest?cta=user&id=4012 Score of 628

9.25.2.3 Column and row padding in tables

https://tex.stackexchange.com/landing/r/digest?cta=question&id=31672

How do you guys go about controlling column padding in tables? 
Update 
To clarify, I'm looking for a way to control both vertical and horizontal padding. So, if I had a simple table like in the ... 
[tables] [spacing] [columns]
 

asked by JustDanyul https://tex.stackexchange.com/landing/r/digest?cta=user&id=8615 Score of 444

answered by Werner https://tex.stackexchange.com/landing/r/digest?cta=user&id=5764 Score of 351

9.25.2.4 Matrix in Latex

https://tex.stackexchange.com/landing/r/digest?cta=question&id=204621

I am new to Latex, and I have been trying to get the matrix of following form 
[x11 x12 x13 . . . . x1n 
x21 x22 x23 . . . . x2n 
. 
. 
. 
. 
xd1 xd2 xd3 . . . . xdn] 
... 
[matrices]
 

asked by Lakshmi Narayanan https://tex.stackexchange.com/landing/r/digest?cta=user&id=63361 Score of 142

answered by skpblack https://tex.stackexchange.com/landing/r/digest?cta=user&id=42912 Score of 211

9.25.2.5 How can I write cases with grouping braces on both left and right side, and split the condition into two lines in LaTeX?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=240868

The code I used to write 
is this one 
$$ 
X(m,n)= 
\begin{cases} 
x(n),\\ 
x(n-1)\\ 
x(n-1) 
\end{cases} 
$$ 
But I don't know how to write this one 
Also, what if I want to write this 
[math-mode] [cases]
 

asked by MaryA~ https://tex.stackexchange.com/landing/r/digest?cta=user&id=65856 Score of 197

answered by Ignasi https://tex.stackexchange.com/landing/r/digest?cta=user&id=1952 Score of 140

9.25.2.6 Forcing linebreaks in \url

https://tex.stackexchange.com/landing/r/digest?cta=question&id=3033

This question led to a new package: 
xurl 
I wish to typeset some relatively long URLs in a piece of text, and when I use \url{..}, the resulting text does not respect the margin boundaries that govern ... 
[line-breaking] [urls]
 

asked by Suresh https://tex.stackexchange.com/landing/r/digest?cta=user&id=103 Score of 340

answered by Suresh https://tex.stackexchange.com/landing/r/digest?cta=user&id=103 Score of 246

9.25.2.7 What is the "correct" way of embedding text into math mode?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=3415

Lets say I have something like: 
\[ Let x = number of cats \] 
(This is a contrived example, but pretend we are actually inside a long align environment block...) "Let" and "number of cats" need to ... 
[math-mode]
                                                                                  

                                                                                  
 

asked by Billy ONeal https://tex.stackexchange.com/landing/r/digest?cta=user&id=192 Score of 275