What should my family do to notify SE if I die?
How should a user's death be handled?
Full URL not working with php include What was the point of testing carbonite-freezing technology on Han Solo? Darth Vader tested carbonite-freezing technology on Han Solo because he didn't want to kill Luke who was precious to the emperor. But, why was it necessary? Wasn't it already a tested and proven technology? Even Darth Vader (when he was Anakin) himself used it along with others decades ago (Star Wars: The Clone Wars S03E18). Proving by induction that $1^3 + 2^3 + 3^3 + \ldots + n^3 = \left[\frac{n(n+1)}{2}\right]^2$ Need guidance on this proof by mathematical induction. I am new to this type of math and don't know how exactly to get started.   $$ 1^3  +  2^3  +  3^3  +  \ldots  +  n^3  =  \left[\frac{n(n+1)}{2}\right]^2 $$ removeClass and fade animation I just updated from Ubuntu 10.10 to 11.04 and have an issue regarding the screen resolution. I have Intel integrated gfx chip and my monitor supports resolutions larger than 1024x768. (in 10.10 I've been using 1280x1024) But as soon as I upgraded, I'm stuck with 1024x768 resolution and seems I can't change it.  running xrandr In terminal yields the following results,   Screen 0: minimum 320 x 200, current 1024 x 768, maximum 4096 x 4096 LVDS1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm    1280x800       58.1 +    1024x768       60.0*     800x600        60.3     56.2      640x480        59.9   VGA1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 344mm x 194mm    1366x768       59.9 +    1360x768       60.0      1024x768       75.1     72.0     70.1     60.0*     832x624        74.6      800x600        72.2     75.0     60.3     56.2      640x480        72.8     75.0     66.7     60.0      720x400        70.1     1280x1024_60.00 (0xce)  109.0MHz         h: width  1280 start 1368 end 1496 total 1712 skew    0 clock   63.7KHz         v: height 1024 start 1027 end 1034 total 1063           clock   59.9Hz   What maybe the problem? Is it a bug? What kind of steps I should take in order to get a higher resolution? (changing xorg.conf maybe?) Any insight is highly appreciated. Thanks in advance.   UPDATE    Screenshot after running xrandr --addmode VGA1 1360x768  As you can see, side bar is not completely visible and Ubuntu logo at the task bar is missing. Also when you open an application, the Task bar of the application (where it should go to the top panel) is missing as well.. Why is $\frac{1}{\infty } \approx 0 $ and $ \frac{1}{0} = {\infty}$? First I have checked the search option but found nothing relevant to my problem and also level of math. I just started learning the language of mathematics, on my own and I have trouble understanding why  $  \frac{1}{\infty } \approx 0 $ and  why $\frac{1}{0} = {\infty}$?  I want to know how exactly do I get to these answers. It might sound strange but it's hard for me as a beginner to picture things like this on my own. Detecting current iPhone input language I used to study at Cambridge School I used to study at Cambridge School.  I am used to studying at Cambridge School.  If the verb is continuous tense, it need to be added "verb to be" before used to? Maximum and minimum of of $f(x)=|x-1|+|x-2|+|x-3|$ Previously I thought this is a universal theorem, for one can prove it in the one dimensional case using variational principal.   However, today I'm doing a homework considering a potential like this:$$V(r)=-V_0\quad(r&lt;a)$$$$ V(r)=0\quad(r&gt;a)$$ and found that there is no bound state when $V_0a^2&lt;\pi^2\hbar^2/8m$.  So what's the condition that we have at least one bound state for 3D and 2D? What are the differences between 32-bit and 64-bit, and which should I choose? What is the difference between 32-bit and 64-bit Ubuntu? I've heard the 64-bit platform performs better and can detect more than 4GB of RAM. Also, while some apps haven't ported to 64-bit yet, ia32-libs lets a 64-bit machine run them.  If so, why not promote 64-bit over 32-bit? Why doesn't my command work when aliased? I use ps -ef | grep catalina | grep -v grep to print the tomcat process running on the system:  kshitiz   7099     1  0 May11 ?        00:02:29 /usr/lib/jvm/jdk1.8.0/bin/java -agentlib:jdwp=transport=dt_socket,suspend=y,address=localhost:38156 -Dcatalina.base=/home/kshitiz/Documents/workspaces/ggts/.metadata/.plugins/org.eclipse.wst.server.core/tmp1 -Dcatalina.home=/opt/tomcat-7.0.42 -Dwtp.deploy=/home/kshitiz/Documents/workspaces/ggts/.metadata/.plugins/org.eclipse.wst.server.core/tmp1/wtpwebapps -Djava.endorsed.dirs=/opt/tomcat-7.0.42/endorsed -Dfile.encoding=UTF-8 -classpath /opt/tomcat-7.0.42/bin/bootstrap.jar:/opt/tomcat-7.0.42/bin/tomcat-juli.jar:/usr/lib/jvm/jdk1.8.0/lib/tools.jar org.apache.catalina.startup.Bootstrap start   Then I use ps -ef | grep catalina | grep -v grep | awk -F' ' '{print $2}' to extract the process id:  7099   But when I alias the whole command alias tomcat_id="ps -ef | grep catalina | grep -v grep | awk -F' ' '{print $2}'" and use it via alias, it prints the whole text and awk doesn't seem to work.  type tomcat_id gives:  tomcat_id is aliased to `ps -ef | grep catalina | grep -v grep | awk -F' ' '{print }'' Let $p$ be an odd prime number. Prove that $$\left( \frac{1 \cdot 2}{p} \right) + \left( \frac{2 \cdot 3}{p} \right) + \left( \frac{3 \cdot 4}{p} \right) + \cdots + \left( \frac{(p-2)(p-1)}{p} \right) = -1$$ where $\left( \frac{a}{p}\right)$ is the Legendre symbol.  This seems to be a tricky one! I've tried using the property $\left( \frac{ab}{p} \right)=\left( \frac{a}{p}\right) \left( \frac{b}{p} \right)$ and prime factoring all the non-primes but to no avail. I had a quick thought of induction haha, but that was silly. I tried factoring the common Legendre symbols like $\left( \frac{3}{p}\right) \left[ \left( \frac{2}{p} \right) + \left( \frac{4}{p} \right) \right]$ but that didn't bring anything either. And I've been looking for pairwise cancellation with $1$ term leftover, but that does not seem to work.  Can you help? zsh: excluding files from a pattern Say I have the following files:   |-- bar `-- foo     |-- type_A_1     |-- type_A_2     |-- type_B_1     |-- type_B_2     |-- type_B_xx     |-- type_B_xx     `-- something_else    I thought the following command  print -l foo/*~{type_B*}   would print everything under foo except things that start with type_B but it doesn't, instead it prints everything under foo:  foo/type_A_1 foo/type_A_2 foo/type_B_1 foo/type_B_2 foo/type_B_xx foo/something_else   I also tried print -l foo/*~type_B and got the same thing.  How does the exception wildcard ~ work in zsh? Number of normal subgroups of a non abelian group of order $21$... CSIR December $2013$ Question is to :  Find the number of Normal subgroups of a nonabelian group $G$ of order $21$ other than $\{e\}$ and $G$.  What I have done so far is :  As $|G|=21=3\cdot7$  we have :  No. of sylow $3$ subgroups $1+3k$ dividing $7$ leaving out possibilities $1$ or $7$  No. of sylow $7$ subgroups $1+7k$ dividing $3$ leaving out only possibilities $1$.  So, we have a unique sylow $7$ subgroup and so it is normal.  I remember somehow that any normal group should come from a normal sylow subgroup or something like that.  S0, I prefer to conclude there is only one Normal subgroup for a non abelian group of order $21$.  Please let me know if this is true and please help me to fill that gap :      I remember somehow that any normal group should come from a normal sylow subgroup or something like that.   Thank you. self referential struct definition? I haven't been writing C for very long, and so I'm not sure about how I should go about doing these sorts of recursive things... I would like each cell to contain another cell, but I get an error along the lines of "field 'child' has incomplete type". What's up?  typedef struct Cell {   int isParent;   Cell child; } Cell; In a preadditive category, products are coproducts $\renewcommand{\phi}{\varphi}$ $\require{AMScd}$ My question is different from .  I want to see how in a preadditive category $\mathcal{C}$ a product is a coproduct, following . I'll write the proof up to the point where I get stuck.  Let $A=A_1,B=A_2$ be objects and suppose their product $P$ does exist, with projections $\pi_i:P\rightarrow A_i$. By considering a wedge  $$\begin{CD}A @&lt;{id_A}&lt;&lt;  A @&gt;{0_{AB}}&gt;&gt;  B\end{CD}$$  and the obvious analogous one with $A$ and $B$ exchanged, where $0_{A,B}$ is the zero morphism, we see that the product property implies the existence of two unique morphisms $k_i\in\mathcal{C}[A_i,P]$ s.t.  \begin{align*} \pi_j\circ k_i=\begin{cases} \mathrm{id}_i &amp;\text{if }i=j\\ 0_{A_i, A_j} &amp;\text{if }i\neq j \end{cases}. \end{align*} Using these equations and the definition of zero morphism, it's easy to see that the morphism $m\equiv k_1\circ \pi_1+ k_2\circ \pi_2$ satisfies $\pi_i\circ m=\pi_i$.   This is where I get stuck: In the linked proof, they now state that this implies $m=\mathrm{id}_P.$ But I don't see why this should be true.   Specifically, if $\phi\in\mathcal{C}[S,P]$ for some arbitrary object $S$, it is not apparent why $m\circ\phi=\phi$. All that we know is that there are some morphisms $x_i\in\mathcal{C}[S,A_i]$ that factor through $P$ via the universal property, but these are not necessarily unique.  And we learn even less about $m$ by looking at morphisms in $\mathcal{C}[P,S]$.  What am I missing here? Using while loop to ssh to multiple servers I have a file servers.txt, with list of servers:  server1.mydomain.com server2.mydomain.com server3.mydomain.com   when I read the file line by line with while and echo each line, all works as expected. All lines are printed.  $ while read HOST ; do echo $HOST ; done &lt; servers.txt server1.mydomain.com server2.mydomain.com server3.mydomain.com   However, when I want to ssh to all servers and execute a command, suddenly my while loop stops working:  $ while read HOST ; do ssh $HOST "uname -a" ; done &lt; servers.txt Linux server1 2.6.30.4-1 #1 SMP Wed Aug 12 19:55:12 EDT 2009 i686 GNU/Linux   This only connects to the first server in the list, not to all of them. I don't understand what is happening here. Can somebody please explain?  This is even stranger, since using for loop works fine:  $ for HOST in $(cat servers.txt ) ; do ssh $HOST "uname -a" ; done Linux server1 2.6.30.4-1 #1 SMP Wed Aug 12 19:55:12 EDT 2009 i686 GNU/Linux Linux server2 2.6.30.4-1 #1 SMP Wed Aug 12 19:55:12 EDT 2009 i686 GNU/Linux Linux server3 2.6.30.4-1 #1 SMP Wed Aug 12 19:55:12 EDT 2009 i686 GNU/Linux   It must be something specific to ssh, because other commands work fine, such as ping:  $ while read HOST ; do ping -c 1 $HOST ; done &lt; servers.txt How can I hide my code in visualforce page? OLS is BLUE. But what if I don't care about unbiasedness and linearity?