overfull and under-full errors. Not able to correct them, please help out
Having Overfull and underfull box warnings. Please help out as there are many matrices and equations
Resolve the error "An illegal choice has been detected..." Why use "need not" instead of "do not need to"? The header of  states:     High-level languages need not be slower than low-level ones.     Why use need not instead of do not need? What does it mean? Also, why no to before be? How to insert pipe symbol in (La)TeX? How to insert pipe symbol | in TeX (LaTeX)?  I have tried this sample with pdflatex tmp.tex  \documentclass{extarticle} \begin{document} \textpipe \end{document}   And it give undefined control sequence error  This is pdfTeX, Version 3.1415926-1.40.10 (TeX Live 2009/Debian) restricted \write18 enabled. entering extended mode (./tmp.tex LaTeX2e &lt;2009/09/24&gt; Babel &lt;v3.8l&gt; and hyphenation patterns for english, usenglishmax, dumylang, noh yphenation, loaded. (/usr/share/texmf-texlive/tex/latex/extsizes/extarticle.cls Document Class: extarticle 1996/10/08 v1.0 Non Standard LaTeX document class (/usr/share/texmf-texlive/tex/latex/base/size10.clo) (/usr/share/texmf-texlive/tex/latex/base/exscale.sty)) No file tmp.aux. ! Undefined control sequence. l.3 \textpipe High Memory Usage on Linux Server How do I make animations a steady speed? When I make an animation, it always starts out slow, then speeds up, then slows down at the end.  I cannot figure out how to fix this. Product of binomial coefficient as a basis so someone tells me i need to call a few people.  they send me a vCard called contacts.vcf.  i import it.  i open my phone app and start to dial, but wait...i don't know their names.  How do i look up a recent vCard on my phone?  How do i know who's contact i've been sent?  when i navigate to a .vcf file, i can't open it.  all i can do is import it.  polaris office won't import/open it.  is there an android txt editor i can use to peruse a vCard?  yours truly, Confused by vCards Note 3, kit kat Intermediate fields between $\mathbb{Z}_2 (\sqrt{x},\sqrt{y})$ and $\mathbb{Z}_2 (x,y)$ Teleporting a player from the overworld to the end Periodic function implies periodic primitive? If $f$ is a periodic function with $T = \pi$, does that mean that $F$ (a primitive of $f$) has the same period ? What about the inverse implication (periodic primitive implies periodic function) ? Determine device (iPhone, iPod Touch) with iOS Is there a way to determine the device running an application. I want to distinguish between iPhone and iPod Touch, if possible. For every matrix $A\in M_{2}( \mathbb{C}) $ there's  $X\in M_{2}( \mathbb{C})$ such that $X^2=A$? Anime about a boy and a girl who ride ostrich-like creatures through a valley I can not remember much but I have had this film in my head for years I searched everything I can remember on every website I can think of.  I don't remember the exact story but I'll list everything about it can   Apocalyptic future possibly Two main characters: a boy and a girl riding ostrich-like creatures through a valley An old blind lady that senses things Crashed spaceship looking like a submarine Giant creatures looks like yaks with blue eyes, whose eyes turn red when something is about to happen The old lady says "Some say they went to the stars" while looking at the spaceship The two main characters do something and their eyes turn blue in the distance and the village cheers   This film is at least ten years old and I would appreciate it so much if you knew anything about it, or could help me find the title. Test -n gives unexpected result I understand test -n &lt;expression&gt; to return false if the expression evaluates to a string length of greater than 0.  Why then does the following happen?  Macbook:~ echo ${#undeclared_variable} 0 Macbook:~ test -n $undeclared_variable &amp;&amp; echo Foo Foo   Bash 4.x  My expectation is that since test -n $undeclared_variable should evaluate false, that Foo should not be echoed.  If I use [[  ]] instead of test, it works as expected. Run Unity on external monitor with Bumblebee Show all of my question/answers to me even if they are deleted I would really like to see all of my questions and answers on the profile page, even if some of them were deleted, and I don't have enough rep to see them on the site. (Note that some questions are  after 30 days or 1 year, and the author might be oblivious about what happened.)   , the &quot;deleted recent [questions/answers]&quot; links in one's own user profile now list all respective posts that were deleted in the past 60 days, rather than just those that were originally posted in the last 60 days. , users with the &quot;access to moderator tools&quot; privilege (10k+ on designed sites, 2k+ on beta and non-designed sites) can use the search operator deleted:1 to see all their own deleted posts. , deleted questions and answers that were posted in the past 60 days, can be seen using the &quot;deleted recent questions&quot; and &quot;deleted recent answers&quot; links on the questions and answers tabs (at the bottom of the tab) in your user profile. For older posts: as of 2013-04-23 you can  if you already have a link to them, but they still aren't linked from the user profiles (not even just for you). Nor do you see inbox notifications for comments on them if you come back a few hours later. You have to have thought to bookmark your question, or you have to go digging for it in your browser history. Three-columns text with figures of 2\columnwidth E:Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages Can this identity be derived from the binomial theorem?  $$n(n+1)2^{n-2} = \sum_{i=1}^{n}  i^2 \binom{n}{i}$$    I tried starting from $2^n = \displaystyle\sum_{i=0}^{n} \binom{n}{i}$ and dividing it by $4$ in order to get $2^{n-2}$. Why is $\sqrt {12} = 2 \sqrt 3$?