Forgot Windows user password
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What is the difference between a "link function" and a "canonical link function" for GLM I've come across a paper that mentions the fact that matrices commute if and only if they share a common basis of eigenvectors. Where can I find a proof of this statement? bilinear form - proof I have to prove that the mapping $f(x,y)={\displaystyle \sum_{i=1}^{n}}{\displaystyle \sum_{j=1}^{n}}x_{i}y_{j}{f}(e_{i},e_{j})$  is a bilinear form, that is, inter alia, the condition: $f(x+y,z)=f(x,z)+f(y,z)$  I have: $f(x+y,z)=f\left({\displaystyle \sum_{i=1}^{n}}x_{i}e_{i}+{\displaystyle \sum_{k=1}^{n}}y_{k}e_{k},{\displaystyle \sum_{j=1}^{n}}z_{j}e_{j}\right)=f\left({\displaystyle \sum_{i=1}^{n}}{\displaystyle \sum_{k=1}^{n}}\left(x_{i}e_{i}+y_{k}e_{k}\right),{\displaystyle \sum_{j=1}^{n}}z_{j}e_{j}\right)=\ldots$  and what's next?  Help! Sequence of differentiable functions Let $f_n$ be a sequence of differentaible functions on $[0,1]$ to $\mathbb{R}$ converging uniformly to a function $f$ on $[0,1]$, Then    $f$ is differentiable and Riemann integrable there $f$ is uniformly continuous and R-integrable $f$ is continuous, need not be differentiable on $(0,1)$ and need not be R-integrable on $ [0,1]$, $f$ need not be continuous.   Well I think 2 is only correct statement  as every $f_n$ are differentiable on $[0,1]$ hence uniformly contnous, and as they converge uniformly to $f$ on $[0,1]$ so $f$ is uniformly continuous and every continuous function is rieman integrable..Am I correct? I just picked up a copy of Windows 7 Pro OEM for install on my computer.  Guy at the store said the only real difference between OEM and standard retail box was tech support.  However, the outside of the box has this big warning that says "The software must be installed with an OPK"?  What is the OPK?  Is it really necessary?  The MS site about it seemed to say it was optional.  EDIT:  BTW - I'm just an individual tinkerer, and not a System Builder Company Employee.  I should have made that clear.  I've used sysprep in a professional setting in the past, so I'm somewhat familiar with its concepts. Solve $x^2+2=y^3$ using infinite descent? I have posted a proof below, and would appreciate it if someone could review it for accuracy. Thanks!   Problem:   Let n $\in$ $\mathbb{Z}$ with $n$ $\ge$ 3. Prove the following:   (a) Z(D$_{2n}$) = 1 if $n$ is odd.   (b) Z(D$_{2n}$) = {1, r$^k$} if $n$ = $2k$.   Note that $r$ and $s$ generate D$_{2n}$ with the group presentation { $r$,$s$ | $r$$^n$ = $s$$^2$ = 1, $rs$ = $sr$$^{-1}$ }   Proof:  part (a)   Let $n$ $\ge$ 3 where $n$ $\in$ $\mathbb{Z}$ and $n$ is odd.   For any x $\in$ Z(D$_{2n}$), x must commute with both $s$ and $r$, since both are in $D_{2n}$. Note that if $x$ commutes with both $s$ an $r$, then $x$ commutes with any element of $D_{2n}$ since $r$ and $s$ generate D$_{2n}$.    Then for any x$\in$ Z(D$_{2n}$), we have $xr$ = $rx$, where x is of the form $x$ = s$^j$r$^w$ (any such element can be arranged into this form via the relation $rs$ = $sr$$^{-1}$ and the fact that $r$ and $s$ generate D$_{2n}$). Note that since r and s have finite order, the exponents are modulo n and modulo 2 for $r$ and $s$ respectively.   Then we have  s$^j$r$^w$$r$ = $r$s$^j$r$^w$.   Which implies s$^j$r$^{w+1}$ = s$^j$r$^{w +- 1}$  In the case where the power of r on the RHS is $w$ - 1, it is clear we cannot have equality unless |r| = 1, which it is not. Note that if $j$ is even then we have only the $w$ + 1 case. Hence $x$ may be of the form $1$$r$$^w$ = $r$$^w$.   Also we have that x must commute with $s$, hence $s$$x$ = $x$$s$.   Then $s$$r$$^w$ = $r$$^w$$s$.  Which implies $s$$r$$^w$ = $s$$r$$^{-w}$.   Applying s$^{-1}$ to both sides we arrive at the task of finding when r$^w$ = r$^{-w}$ i.e when $w$ = $-w$. But since r has finite order we have:   $$ \bar{w} = (n-1)*w $$   where $\bar{w}$ is the residue class of w modulo n. Hence for some a $\in$ $\mathbb{Z}$$_+$   $$ w + an = wn - w $$  $$ 2w = wn - an $$ $$ 2w = n(w-a) $$   Now since 0 $\lt$ w $\le$ n we have that the LHS is greater than 0. Also since n $\ge$ w then (w-a) $\le$ 2, since otherwise the RHS would be greater than the LHS. So since n is odd we must have that (w-a) is even and hence (w-a) = 2, implying that 2w = 2n and hence n = w.   Hence x = $r$$^w$ = $r$$^n$ = 1. So Z(D$_{2n}$) = 1.   part (b)   From the argument above any x $\in$ Z(D$_{2n}$) must be of the form $s$$^j$$r$$^w$ for j even and j $\in$ $\mathbb{Z}$. Then x is of the form $r$$^w$ for $0$ $\lt$ w $\le$ $n$. Since $n$ is even we have the equation below is satisfied when $2w$ = $n$ or $w$ = $n$, since (w-a) $\le$ 2 but also (w-a) $\ge$ 0 for (w-a) $\in$ $\mathbb{Z}$$_+$.   $$ 2w = n(w - a) $$   Hence $r$$^w$ $\in$ Z(D$_{2n}$) when $2w$ = $n$, as desired. Option to contact moderators Due to some "recent issues", I think the following is necessary:  Users need a way to contact moderators through the StackOverflow website.  This is especially important for suspensions, where there is no way to appeal or discuss the suspension from within SO itself.  Basically, there would be some kind of a box on the user's page that allows them to mention something to the moderators and some way to read the replies. (Or they could just go to the user's email.) I was given the files for a mini linux, that boots directly into firefox. It works for all it should be doing, only that I do not get an internet connection.  We have 3 DNS servers in the network, which all work. I can ping them, too. But when trying to ping google.de or wget google.de I get a bad address error.  nslookup google.de works for some reason.  I tracked the issue down to my resolv.conf on the booted system not having the same contents as the resolv.conf that I put into the .iso file.  I tried understanding all the factors that go into creating and modifying resolv.conf. I'm not quite sure I got it all, but I definitely didn't find my solution there.  So as a last ditch effort, I tried making the resolv.conf file immutable using   :~# chattr +i /etc/resolv.conf   When rebuilding and booting again to my surprise my file was renamed to resolv.conf~ and in its place was the same standard file that has been haunting me.   The file contents make me believe it gets the information from the network itself. When starting the .iso in Virtualbox without internet access, my file is being kept as it is.  I tried changing /etc/dhcp/dhclient.conf to not get the information from the net, by deleting domain-name-server and domain-name-search from the request part of the file.  Didn't work unfortunately.  I don't have the NetworkManager installed. The iso is based on Ubuntu 14.04.  There is probably vital information missing. I'm happy to provide it.  UPDATE:  I think I found the file that clears resolv.conf.  It seems to be /usr/share/udhcpc/default.script  #!/bin/sh  # udhcpc script edited by Tim Riker &lt;Tim@Rikers.org&gt;  [ -z "$1" ] &amp;&amp; echo "Error: should be called from udhcpc" &amp;&amp; exit 1  RESOLV_CONF="/etc/resolv.conf" [ - n "$broadcast" ] &amp;&amp; BROADCAST="broadcast $broadcast" [ -n "$subnet" ] &amp;&amp; NETMASK="netmask $subnet"  case "$1" in     deconfig)         /bin/ifconfig $interface 0.0.0.0         for i in /etc/ipdown.d/*; do             [ -e $i ] &amp;&amp; . $i $interface         done         ;;      renew|bound)         /bin/ifconfig $interface $ip $BROADCAST $NETMASK          if [ -n "$router" ] ; then             echo "deleting routers"             while route del default gw 0.0.0.0 dev $interface ; do                 :             done              metric=0             for i in $router ; do                 route add default gw $i dev $interface metric $((metric++))             done         fi          echo -n &gt; $RESOLV_CONF # Start ----------------           [ -n "$domain" ] &amp;&amp; echo search $domain &gt;&gt; $RESOLV_CONF         for i in $dns ; do             echo adding dns $i             echo nameserver $i &gt;&gt; $RESOLV_CONF         done         for i in /etc/ipup.d/*; do             [ -e $i ] &amp;&amp; . $i $interface $ip $dns          done # End ------------------         ;; esac  exit 0   It's part of the udhcpc program. A tiny dhcp client, that is part of busybox  Will investigate further.    UPDATE2 AND SOLUTION:  I commented the part out (#Start to #End), that seemingly overwrites the /etc/resolv.conf file and sure enough. That was the culprit. So an obscure script caused all this trouble.  I changed the question to reflect, what actually needed to be known to solve my problem, so it would be easier to find for people with the same problem and so I could accept an answer.  Thanks for the help here in figuring things out. Once a post has been edited, you can go into the revision list, and click "View Source".  If a post has not been edited (and I don't have the edit privilege) is there any way to see the raw Markdown?  The reason I ask I because of  - it's impossible to see the source markdown, and how it's different from the rendered Markdown.  Not exactly a huge issue, just curious! Where did Harry's parents get all of their money from? So, at the beginning of Harry Potter, Harry is found to have a large vault of gold at Gringotts. Where did all of that money come from? What did James (I assume it came from him, as Lily was muggle-born, and they were both young) do to get all of that cash? Help with proof of $|x+y| \geq |x|-|y|$ My university's thesis guidelines require that each bibliographic entry appear in whole on a single page, rather than being split across two. How can I prevent (La)TeX breaking a paragraph across a page boundary? Add manually installed application to 'Show Applications' grid in Ubuntu 18.04 How to run Visual Studio post-build events for debug build only How can I limit my post-build events to running only for one type of build?  I'm using the events to copy DLL files to a local IIS virtual directory, but I don't want this happening on the build server in release mode. Completing a 3x3 correlation matrix: two coefficients of the three given I was asked this question in an interview.  Lets say we have a correlation matrix of the form \begin{bmatrix}1&amp;0.6&amp;0.8\\0.6&amp;1&amp;\gamma\\0.8&amp;\gamma&amp;1\end{bmatrix}  I was asked to find the value of gamma, given this correlation matrix. I thought I could do something with the eigenvalues, since they should be all greater than or equal to 0.(Matrix should be positive semidefinite) - but I don't think this approach will yield the answer. I am missing a trick.  Could you please provide a hint to solve for the same? How do I reset GNOME to the defaults? I was playing around with some settings, and now I need to reset GNOME to it's defaults - how do I do that? What is the difference between Shrink Database and File? DBCC ShrinkDatabase() DBCC ShrinkFile()    Do I need to run both DBCC commands in order to shrink the database? What is the difference between these two above? Which manuals are on your "TeX Reference" shelf? This is a community wiki since there is no "one true answer"- if you find an answer that contains a lot of your choices, but is missing something you feel is incredibly useful.  Feel free to add it.  A short description of what topics the reference covers would be nice as well.  Organize by subject please.  For example: I always keep the following PDFs at my fingertips.  Document Layout   :  Covers, in exquisite detail, how to produce just about any document using the memoir LaTeX class. ( 4.5 MB)   Mathematical Typesetting   : A document by Herbert Voß that explains how to typeset just about any mathematical expression in LaTeX. ( 2 MB)   Graphics   : Explains, with examples, how to draw just about any figure using PGF/TikZ.  Also a good example of what awesome documentation should look like. ( 9.5 MB) Do I need an airport transit visa through Switzerland if I have no Schengen visa? Am traveling from Cairo to Moscow via Swiss Air