Show that the orthogonal operator is a Skew-symmetric operator
Linear algebra skew symmetric
Where do AirDrop files go when I transfer them between an iPad, iPhone and iPod? I AirDropped some Google Docs from my iPad to my iPhone but nothing happened; where did my files go? The file was a list of tools. "All I need (is/are) cigarettes and alcohol": which one is correct? In one of Oasis's songs — Cigarettes and Alcohol — there are two sentences that make me confused:     All I found was cigarettes and alcohol   ...and...     All I need is cigarettes and alcohol   Why would is and was be correct in these sentences instead of are and were, since they're referring to more than one thing? How can I manually install a package on MiKTeX (Windows) Why did skilled wizards use He-Who-Must-Not-Be-Named? Pursuant to , it's plausible that the typical witch or wizard would use 'He-Who-Must-Not-Be-Named' (if they assume Taboo Spell is intact after death of Voldemort). But, why would the Aurors and those in the Ministry of Magic (who had first rate protection) also use it? Even Snape (the Half-Blood Prince) hesitated to say 'Voldemort', and he was under the protection of Dumbledore, Dumbledore being the only wizard Voldemort ever feared.  What was the point of the Death Eaters being scared to say 'Voldemort' when, ostensibly, Voldemort wasn't even alive? Yes, it's true that some believed Voldemort would return, but, at the time, it was just that -- a belief. Were people scared that the Death Eaters might give a list of all those who used Voldemort's name to Voldemort upon his return? Why does Linux show both more and less memory than I physically have installed? Can we prevent titles with an unnecessary tag in them? SQL - Query to get server's IP address I prefer to use bm package to bold math. However, I noticed that when used with eulervm, this gives inconsistent results for ‘&lt;’ and ‘>’ characters.  I wonder what causes it and can the usage bm be fixed to get proper ‘&lt;’.  \documentclass{article}  \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc}  %\usepackage{amsmath}  \usepackage[euler-digits,euler-hat-accent]{eulervm}  \usepackage{bm}  \begin{document}      \texttt{\hphantom{mathbold}\llap{bm}}: \quad $ 1 + 1 &lt; 3; \quad \bm{1 + 1 &lt; 3} $      \texttt{mathbold}: \quad $ 1 + 1 &lt; 3; \quad \mathbold{1 + 1 &lt; 3} $  \end{document} How can I get numbered classes on rows? I worked briefly with Drupal 7 and I thought it was possible there but in Drupal 8 is it possible to have a view output an increasing numbered CSS classes for Views rows?  This is what I want.  &lt;div class="view"&gt;   &lt;div class="view-row-1"&gt;&lt;/div&gt;   &lt;div class="view-row-2"&gt;&lt;/div&gt;   &lt;div class="view-row-3"&gt;&lt;/div&gt;   &lt;div class="view-row-4"&gt;&lt;/div&gt; &lt;/div&gt;   I know I can add a CSS class to every row and give every row the same class. Display Database Instance Relationship with TikZ I'm trying to display all of my corporate database instances and their relationship to each other, so to speak the database links. I found the geometry shape cylinder using TikZ \usetikzlibrary{shapes.geometric}, but I'm new to the whole TikZ stuff and it doesn't worked out that well so I thought maybe you could help me getting something like the following figure:    There will be a ton of instances and arrows, but I hope that you guys could give me a start so that I could do the rest on my own. How do I Sort a Multidimensional Array in PHP biblatex: separator for citing multiple sources, some of them with page, some not I'm using biblatex for my references.  Normally, if I use \cite{source1, source2, source3}, I get a citation like  [3, 45, 98]   If I now want to give a page number for one of them, it looks confusing imho, as I should get (did not try it out up to now, honestly)   [3, 45, 78, p. 23f, 98]   So imho it would make sense to change one of the separator from a comma to e. g. a semicolon like:  [3; 45; 78, p. 23f; 98]   Question 1: Does that make sense, or are there other conventions for citing sources with and without page numbers together?  (Up to now I collected the citations without page number in one cite command and added singular \cite[][p. xy]{} commands for those with page numbers., so I'd get:   [3, 45, 98][78, p. 23f]   )  the \cites[]{}[]{}[]{} could also do that, but it also uses the same separators for entries and postnotes.  Question 2: How could I change the separator globally for those number-citations from comma to semicolon in biblatex? This is, how I download various master branches from GitHub, and I aim to have a prettier script (and maybe more reliable?).  wget -P ~/ https://github.com/user/repository/archive/master.zip unzip ~/master.zip mv ~/*-master ~/dir-name   Can this be shorten to one line somehow, maybe with tar and pipe?  Please address issues of downloading directly to the home directory ~/ and having a certain name for the directory (mv really needed?). Can White Walkers talk? Through all the five seasons of Game of Thrones we had never seen a White Walker talking.  Does this mean they can't talk human language (e.g. they have their own language) or we will never see them talking (i.e. they can't talk at all)? Layout selector missing Remove .php extension with .htaccess In our network the name of the network domain is also the domain of the organization's website (say, example.com). Externally, people can enter example.com to visit our website, but internally, this points to one of the several domain controllers, we have for Active Directory, some of which do not even run a webserver.   As a result of this, links to http://example.com don't work internally (only www.example.com does work internally).  How do we point http requests transparently to the web server, and what side effects does this have? Missing return statement in a non-void method compiles Unhandled event loop exception in plugin org.eclipse.ui ID for Contact portion of Person Account Is it possible to get the ID of a Contact which is part of a Person Account?  I have a custom object which has a custom field referencing the Person Account, though it seems to be referencing the Contact directly. I have created a button which I am using to pass the ID into a Visualforce Page.  With the Insert Field drop-down on the create/edit button page I can put in {!Account.Id} or {!Contact.Id} but neither of these work. The Account ID is placed in the URL but is not the correct ID and the Contact ID is blank, which I assume is because the button is on a Person Account page and not a Contact Page.