how to find $|GL_2(F_p)|$
Order of general- and special linear groups over finite fields.
Frequency Detection Circuit Design How can I make a camera the active one? I have multiple cameras in a scene. What I want to do is to change which one is active. This way I can view the scene from different angles. How would I do this? I just signed up, a day or two ago, and I've received a notification that there's something in my inbox.  Unfortunately, my email client isn't able to show me a link to my Inbox, or the message, because of the format of the email.  I normally use the email address that I gave when I signed up, just with MailWasher, which is intended to safely preview emails, as plain text, to decide whether or not to open them in a normal HTML email client.  I would be nice if that email contained a link to my inbox, which could be shown in MailWasher.  In order to collect that email in a normal email client, I'd also have to collect or delete all the other emails sent to that address.  I'm not entirely clear what's been done in that email to stop MailWasher seeing the link.  I can see a link to leave feedback, and one to unsubscribe, but not one to check my inbox.  Sure, I can live without one, but those emails would be a lot more useful to me if I could just click a link to go to my Inbox. Is it acceptable to say "fed up OF" - surely it should be "fed up WITH" or "bored WITH something" rather than "bored OF something"? Your summary page shows "N Edits to your posts" for the selected time period but you really have to be looking for it.  Could we add edits to the notification feed? You could put the reason for the edit (entered--or not--when the editor changes it) and just a link to the post. Regression with only categorical variables I have put together a map using the British OS Strategi data set which is pretty densely detailed. It is surveyed at 1:250,000 and so contains roads down to track level, rivers, villages, railway lines - you name it. There's a lot of data.  When I try and export an image version of the map (at about 1m x 1m), I always get an 'Exception: bad allocation' error. This happens when I try to export as a raster image or PDF. I have tried printing to a PDF generator (CutePDF) but the same thing happens. The print spooler shows the file size at 1.6Gb.  I am running QGIS on a dual core 2ghz Windows 8 system with 4Gb of RAM. Is it just a case of the file being too big? Is there anything I can do? Or is there an alternative, free GIS package that would do a similar job? How to resolve "Failed to download repository information"? Whenever I try to install anything with the Ubuntu Software Center, the following error appears.     Failed to download repository information      Check your Internet connection.      E:Unable to parse package file /var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise_multiverse_i18n_Index (1) Is it possible to induce Mathematica to chop off parts of Graphics objects that exist outside of a Frame? Removing clock from the lock-screen I'm using Ubuntu 18.04.  I want to remove the digital clock from the lock screen because I just want to see a good wallpaper there, unobstructed.   How do I go about this? I just noticed . Hey! I'm there! But that's beside the point.  The point is that Nick Craver is there too. Nick seems to like really long tag names, so his profile shows up like this:    Akk! Diamonds everywhere!  It seems that the page is optimized for only two lines of tags per user. One tag per line means three lines. Three lines means that Nick's reputation (tag) is cut in half.  Let's not cut Nick's rep (tag) in half on the Users page, no? Java Swing: Displaying images from within a Jar When running a Java app from eclipse my ImageIcon shows up just fine.  But after creating a jar the path to the image obviously gets screwed up.  Is there a way to extract an image from the jar at runtime so I can then open it up?  Or, is there a better way to do this?  I'd like to distribute a single jar file if possible. If $A,B,C$ are matrices I am thinking how to show that $$ A(B + C) = AB + AC$$  Is possible to show without sums like $\sum_i a_i, ..., \sum_j b_j$? It seems if I do the proof with many indexes then is tedious and I don't learn much from it. Is there a particle called a "tachyon" that can travel faster than light?  If so, would Einstein's relativity be wrong?  According to Einstein no particle can travel faster than light. I am stuck in a question for Algebraic Structures:  I need to prove: If given any ring $R$, for any $a$ in $R$ $a\cdot a=0$ then $a+a=0$.  (of course $+$, $*$ and $0$ regarding $R$)  I didn't find any question regarding this question. What do damage buffs affect? In Overwatch, there are several ways to buff the damage dealt by a hero: the alternate fire of Mercy's Caduceus Staff, Ana's Nano Boost, and Orisa's Supercharger. Are they all governed by the same rules? What can they affect, or not affect?  This question exists to have a single reference point for the many, many questions that have been asked, instead of having to update each answer individually when game mechanics change Sum over all non-evil numbers How to access the grub boot menu in order to generate bootchart? I am running Ubuntu Gnome 15.04, and I want to generate a bootchart to help me diagnose some system problems. However in  it says:    So how do I access the grub boot menu in order to append this text? And just to be clear, how should the line look once I have appended the necessary text? Also, is grub already installed for I don't appear to have either or these packages: grub or grub2?    OS Information:  No LSB modules are available. Distributor ID: Ubuntu Description:    Ubuntu 15.04 Release:    15.04 Codename:   vivid How can I get this symbol without using bbold? A solution I saw somewhere suggested to use   \usepackage{bbold} $\mathbb{1}$   which works well and I get what I want. However, now other symbols used to represent real numbers, natural numbers, etc look ugly.    I'd like them to look (without using bbold)    I'd like to only use that package to achieve that strange double one. Is there any way I can do that? Properties of $\liminf$ and $\limsup$ of sum of sequences: $\limsup s_n + \liminf t_n \leq \limsup (s_n + t_n) \leq \limsup s_n + \limsup t_n$ Let $\{s_n\}$ and $\{t_n\}$ be sequences.  I've noticed this inequality in a few analysis textbooks that I have come across, so I've started to think this can't be a typo:  $\limsup\limits_{n \rightarrow \infty} s_n + \liminf\limits_{n \rightarrow \infty} t_n \leq \limsup\limits_{n \rightarrow \infty} (s_n + t_n) \leq \limsup\limits_{n \rightarrow \infty} s_n + \limsup\limits_{n \rightarrow \infty} t_n$.  I understand the right two-thirds of the equation, and can prove it.  I'm stuck on the far-left third.  I don't understand how that is true.