This has been working before, see e.g.  for reference. The png picture is in the same folder as the latex document. Do I miss anything?  \documentclass[12pt]{article}  \usepackage{fancyhdr} \usepackage[ngerman]{babel} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} \usepackage{graphicx} \usepackage{epstopdf} \usepackage{mathtools} \usepackage{amsmath} \usepackage{amssymb} \usepackage{url} \usepackage[parfill]{parskip} \usepackage{enumerate} \usepackage{framed} \usepackage{xcolor}  \begin{document}  Start with nice text...  \begin{figure}[h!] \centering   \includegraphics[width=0.5\textwidth]{Temperatur.png}   %\caption{}     %\caption{Schema des Verkehrsflusses \protect\\\hspace{\textwidth} aus http://www.mathe.tu-freiberg.de/~bernstei/HMI/Verkehr.html.   %\label{} \end{figure}  \end{document}   The first part of the error:

After updating MiKTeX graphics package on 10/5/19 to version 1.3b (packaged on 10/4/2019 8:11:27 PM), I am unable to compile LaTex files that contain \includegraphics{}.  My system: Windows 10  with MiKTeX 2.9.7200  A minimum working example:  \documentclass{article} \usepackage{graphics}  \begin{document}  \begin{figure}    \includegraphics{MC_Antenna_Gain} \end{figure}  \end{document}   The error report   This is pdfTeX, Version 3.14159265-2.6-1.40.20 (MiKTeX 2.9.7200) entering extended mode (C:/Users/nicrog/Dropbox/T_P_2/Scholar/Grants/Written/EWU_20/Test.tex LaTeX2e <2018-12-01> ("C:\Program Files (x86)\MiKTeX 2.9\tex/latex/base\article.cls" Document Class: article 2019/08/27 v1.4j Standard LaTeX document class ("C:\Program Files (x86)\MiKTeX 2.9\tex/latex/base\size10.clo")) ("C:\Program Files (x86)\MiKTeX 2.9\tex/latex/graphics\graphics.sty" ("C:\Program Files (x86)\MiKTeX 2.9\tex/latex/graphics\trig.sty") ("C:\Program Files (x86)\MiKTeX 2.9\tex/latex/graphics-cfg\graphics.cfg") ("C:\Program Files (x86)\MiKTeX 2.9\tex/latex/graphics-def\pdftex.def")) No file Test.aux. ("C:\Program Files (x86)\MiKTeX 2.9\tex/context/base/mkii\supp-pdf.mkii" [Loading MPS to PDF converter (version 2006.09.02).] ) ("C:\Program Files (x86)\MiKTeX 2.9\tex/latex/oberdiek\epstopdf-base.sty" ("C:\Program Files (x86)\MiKTeX 2.9\tex/generic/oberdiek\infwarerr.sty") ("C:\Program Files (x86)\MiKTeX 2.9\tex/latex/oberdiek\grfext.sty" ("C:\Program Files (x86)\MiKTeX 2.9\tex/generic/oberdiek\kvdefinekeys.sty" ("C:\Program Files (x86)\MiKTeX 2.9\tex/generic/oberdiek\ltxcmds.sty"))) ("C:\Program Files (x86)\MiKTeX 2.9\tex/latex/oberdiek\kvoptions.sty" ("C:\Program Files (x86)\MiKTeX 2.9\tex/latex/graphics\keyval.sty") ("C:\Program Files (x86)\MiKTeX 2.9\tex/generic/oberdiek\kvsetkeys.sty" ("C:\Program Files (x86)\MiKTeX 2.9\tex/generic/oberdiek\etexcmds.sty" ("C:\Program Files (x86)\MiKTeX 2.9\tex/generic/oberdiek\ifluatex.sty")))) ("C:\Program Files (x86)\MiKTeX 2.9\tex/generic/oberdiek\pdftexcmds.sty" ("C:\Program Files (x86)\MiKTeX 2.9\tex/generic/oberdiek\ifpdf.sty"))) ! Undefined control sequence. \Ginclude@graphics ...\Ginput@path \set@curr@file                                                    {#1}\edef \uq@curr@file {\... l.8    \includegraphics{MC_Antenna_Gain}  ?    I will report this potential bug to  as well.


I hold a Singapore passport but my tourist stay under the 90/180 Schengen rule has expired. I'm currently in Croatia (not under Schengen rule) and want to travel to UK (also not under Schengen rule) but the flight I booked will transit in Zurich airport. Will I be allowed to transit?

I found many related questions on this site but I am still not sure about the rules. How can I decide if I need a visa to transit? Schengen members as of May 2021 are as follows:  Austria Belgium Czech Republic Denmark (excluding Greenland and the Faroe Islands - but an open border with the Schengen Area is maintained) Estonia Finland France (excluding overseas departments and collectivities) Germany Greece Hungary Iceland Italy Latvia Liechtenstein Lithuania Luxembourg Malta Netherlands (excluding Aruba, Curaçao, Sint Maarten and the Caribbean Netherlands) Norway (excluding Svalbard) Poland Portugal Slovakia Slovenia Spain (except Ceuta and Melilla) Sweden Switzerland


My MacBook Pro was stolen. Is it possible to figure out what Apple ID is now associated with my MacBook Pro using its serial number? Is there a way I can still track down my macbook pro in the event that the one who took or "borrowed" my MBP... 1) Did not connect to the internet 2) Clean installed the OS (boot from USB, then reformatted the Hard Drive/Macintosh HD) 3) Reset the PRAM and NVRAM 4) Installed his own or new Apple ID credentials to iCloud I really just need to know realistically, if whoever took it did this. Is there still a chance I can get it back or at least track its location or who has it.

My MacBook Air was stolen. Can you see what Apple ID is now associated with my MacBook Air using its serial number?


I have this expression for the gravitational force between 2 masses when the gr term is added:  $$F = - \frac{GMm}{r^2} + \frac{4G^2mM(M+m)}{r^4c^2}$$  which I got from the internet since I haven't bee able to find a similar expression in any book. But i'm not sure if it's right or needs fixing.  Is the second term in the force correct?

The gravitational force on your body, called your weight, pushes you down onto the floor. $$W=mg$$ So, what is the weight equation through general relativity?


I didn't go to the office yesterday. I didn't go to work yesterday.  Why is the article 'the' omitted in the second sentence.

Why is this sentence wrong about the article usage?     Don't be late for the school.   I was told that the correct sentence is Don't be late for School.


Currently I'm storing timestamps in the database like such 1378852898   How can I check this against the current time() to see if it's within the last 10mins with PHP?

How to calculate minute difference between two date-times in PHP?


I've just been wondering: Is $$\lim_{n\to\infty}\frac{p_{n+1}}{p_n}=1$$ Essentially I am asking if the primes become more spread out the larger they are, or if the ratio between successive terms decreases adymptotically to $1$. Thanks for any comments or responses.

The Bertrand postulate is that $p_{n+1} < 2p_{n}$ but it is far to be enough to conclude.   I made a program in $R$, to see the convergence of this sequence for the first $500$ prime numbers and it seems to converge to 1. Is this true, and how to prove it ?


In the desktop view I can do a search in Stack Exchange and it will list out all the various sites where it can find out the term whether it may be Stack Overflow, Linux and Unix, Cryptography etc.  Can you please provide the same search feature in Android mobile app also?

Is it possible to search for a question across all Stack Exchange sites in the Android app?   Right now I can search in only one specific site at a time.   If not, can you add that feature?


At the end of Back to the Future II, a lightning bolt hits the DeLorean which sends it back to 1885.  At the time though, the DeLorean wasn't moving; it was relatively stationary hovering in the storm.  Yet, it's emphasised repeatedly that the DeLorean must reach 88 miles per hour (which becomes a key plot point in Back to the Future III).  So, considering the DeLorean wasn't traveling at 88mph when the lightning struck the DeLorean sending it to 1885, what is the in-universe explanation of how it travelled there?  Some other factors to bear in mind:   If a lightning bolt was sufficient to send the DeLorean time traveling, then the 88mph business would be irrelevant Note that there are the firey tracks left after the DeLorean time travels in the '66' shape.  The thing to note about this though is that we never see these before the DeLorean disappears.  These tracks are always appearing after the DeLorean has traveled away.  This would seem to indicate that the DeLorean did move, but following the activation of the time circuits.

It seems to be a commonly accepted theory that the car skidded before going back to 1855. However, the car didn't really seem to skid, so much as explode. It certainly didn't appear to move in such a way that could possibly make those fire skid marks.  That said, I have a feeling the writers intended for the number 99 to be a way to pay tribute to some important event.  It might be possible that perhaps this was a tribute to Jules Verne. Michael Strogoff was publish 99 years before the movie was released. Dr. Brown's son, Jules, was also according to  born 99 years before the first film began (Jules had a brother named Verne). However, I can't help but wonder why Back To The Future would have a reference to a book that itself wasn't even a science fiction.  Or, perhaps that was the speed the doc was moving (I guessing the faster you go, the harder it is to control the time in which the Flux Capacitor will send you, which could explain why Doc was sent to the old west). But, I can't imagine the speed would appear in backward flames like that.  Does anyone have a more solid theory?


So just for fun I created a small little python script that prompts the user for a number and then prints out that many digits of the Fibonacci sequence. The script that I came up with works, but I can't help but feel its a bit convoluted and there is a probably a better and simpler way to do it.  How could I simplify this script and still have it accomplish the same thing?  def fib(number):     if number == 0:         return 0     elif number == 1:         return 1     else:         numbers = [1, 1]         for i in range(number - 2):             i = numbers[-2] + numbers[-1]             numbers.append(i)         return numbers  x = int(raw_input("How many digits of the Fibonacci sequence would you like to see?"))  Results = fib(x)  print Results

I had originally coded the program wrongly. Instead of returning the Fibonacci numbers between a range (ie. startNumber 1, endNumber 20 should = only those numbers between 1 & 20), I have written for the program to display all Fibonacci numbers between a range (ie. startNumber 1, endNumber 20 displays = First 20 Fibonacci numbers). I thought I had a sure-fire code. I also do not see why this is happening.  startNumber = int(raw_input("Enter the start number here ")) endNumber = int(raw_input("Enter the end number here "))  def fib(n):     if n < 2:         return n     return fib(n-2) + fib(n-1)  print map(fib, range(startNumber, endNumber))   Someone pointed out in my Part II (which was closed for being a duplicate - ) that I need to pass the startNumber and endNumber through a generator using a while loop. Can someone please point me in the direction on how to do this? Any help is welcome.    I'm a learning programmer and I've run into a bit of a jumble. I am asked to write a program that will compute and display Fibonacci's Sequence by a user inputted start number and end number (ie. startNumber = 20 endNumber = 100 and it will display only the numbers between that range). The trick is to use it inclusively (which I do not know how to do in Python? - I'm assuming this means to use an inclusive range?).  What I have so far is no actual coding but rather:   Write Fib sequence formula to infinite Display startNumber to endNumber only from Fib sequence.   I have no idea where to start and I am asking for ideas or insight into how to write this. I also have tried to write the Fib sequence forumla but I get lost on that as well.


I need to prove this  Prove that a Gauss integer $z = a +ib$, with $a \ne 0, b \ne 0$ is irreducible if and only if $a^2 + b^2$ is a prime element in ℤ.  I've already proved that $N(z)$ prime implies, $z$ irreducible element: If $N(z)$ is a prime, then $z$ is irreducible since if we write it as $z=xy$, it follows that $N(z) = N(x)N(y)$, thus either $x$ or $y$ is a unit. I'm not able to prove the converse: if z is irreducible then $N(z)$ is prime , which is no generally true, but it is for this particular case with $a \ne 0, b \ne 0$. Note The unique factorization theorem was not still introduce so far in the course and I'd like not to resort on it.

Show that if $a+bi$ is irreducible over $\mathbb{Z} [i]$ then $a^2 + b^2$ is prime over $\mathbb{Z} $ . (a,b are non-zero integers)  I know that $\mathbb{Z} [i]$ is a Euclidean domain and so  $a+bi$ is prime in it. Can I say that as the norm of  $a+bi$ is $a^2 + b^2$ that $a^2 + b^2$ must be prime over $\mathbb{Z} $? This doesn't seem correct to me but it's the best try I have been able to come up with.


The function is:  public Integer[] details; private void putDetails(Integer l){     if (l != null){         int n = new Integer(0);         n = details[l];         details[l]=n+1;     } }   The error message say:  java.lang.NullPointerException     at operacional.an_lex.putDetails(an_lex.java:30)   where the line 30 is : n = details[l];  Can you help me?

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I have an Asus EEE PC 701 laptop with 7" 800x480 screen running Debian Jessie with Openbox as a WM. As I try to maximally use all the capabilities of this laptop, I'm searching for a way to get a dynamically-configurable dual monitor setup, so that when I feel limited by this laptop's small screen, I can just attach an external monitor and it will work. However, there seems to be little or no information about it, keeping in mind that I have integrated Intel GPU with one VGA output. The question is - what should I install&&configure in order to just plug in a monitor in my laptop and instantly have my workspace extended?

is there a tool which enables one to:   remember current RandR configuration (position, orientation, resolution etc) on per-monitor basis, automatically apply last known good configuration as soon as the display is plugged in, with no need to muck around with applets or xrandr(1)?   The configurations would have to be applied on a per-user, per-display basis.   If there is no such tool in the wild, I'd like to throw together one myself, but as far as I can see, there's no way to tell that a monitor has been plugged in. Do I have to poll with xrandr -q once in a while to figure out that an output was connected or disconnected, or is there a more efficient way to do it? Can udev be tuned to do just that?


I noticed that the newest data for some tags from Stack Overflow is a week old. An example is here:    Why is that?

I went to check some of my queries against UNIX & Linux this morning and noticed that the results all had dates older than a week. Going to   query, I see that U&L is among the sites whose most recent posts/comments are 2020-04-19 instead of 2020-04-26, as expected. Partial results of incompletely-refreshed sites are:  ... StackExchange.Meta                    2020-04-19 05:15:09 comments  StackExchange.Ubuntu                  2020-04-19 05:08:40 comments  StackExchange.Stats                   2020-04-19 05:06:54 comments  StackExchange.Ubuntu                  2020-04-19 05:02:17 posts     StackExchange.Programmers             2020-04-19 04:51:22 comments  StackExchange.Programmers             2020-04-19 04:48:14 posts     StackExchange.Gaming                  2020-04-19 04:46:57 posts     StackExchange.Stats                   2020-04-19 04:40:08 posts     StackExchange.Meta                    2020-04-19 04:36:48 posts     StackExchange.English                 2020-04-19 04:34:46 comments  StackExchange.Math                    2020-04-19 04:32:38 comments  StackExchange.Tex                     2020-04-19 04:25:59 posts     StackExchange.Math                    2020-04-19 04:22:14 posts     StackExchange.Tex                     2020-04-19 04:19:32 comments  StackExchange.Unix                    2020-04-19 04:17:12 comments  StackExchange.English                 2020-04-19 04:15:42 posts     StackExchange.Unix                    2020-04-19 04:15:31 posts     StackExchange.Gis                     2020-04-19 04:14:44 posts     StackExchange.Electronics             2020-04-19 04:11:13 comments  ...   Sorting by date doesn't make it obvious to me where the refresh died/stopped, but hopefully this post alerts the correct people.


I have a seagate 320 GB hdd on my linux machine. From a week, SMART utility has been warning me to backup as the disk failure is imminent.   Report failed on the "Bad sectors attribute" which is  Normalized: 1 Worst: 1 Threshold: 36 Value: 4095 sectors  I don't know the meaning of these terms. Can someone please explain and suggest me what to do? Will reformatting the entire hard disk help?  P.S. I can't post the images of the SMART report since my reputation points are less than 10.  EDIT: How can I tell when will the disk fail? Any measures to extend the life by some weeks?

I have an 1 TB data disk and the bios and Windows are reporting a "Smart" error. At least, I get a Smart event but it doesn't indicate how serious the failure could be. My system is about 6 months old, including the disk so the warranty will cover the damage. Unfortunately, I lack a second disk of 1 TB in size which I can use to make a full backup. The most important data on this disk is safe, but there's a lot of work data which can be regenerated but this would cost a lot of time.  So I ordered an USB disk of 1 TB which will arrive in three days. By then I can make a full backup of the data and afterwards, it can crash.  But will the disk live that long? (Well, I won't use the PC as long as I can't make a backup.) How serious is such a Smart event? I know it's serious enough to have it replaced, but will it live for another week or could it die any moment?Update: I purchased an 1 TB external disk and spent most of the day making a backup of the 1 TB disk. It survived that. I then received a new disk, since it was still under warranty and replaced the hard disk. Then I had to spend most of a day again to put back the backup. I need to send back the faulty disk and now have an additional external disk, which could always be practical. :-)  The Smart Error report did not cause any failures on the original disk. I won't advise to ignore these warnings, but the disk still has enough life in it to last a few more days. (Just make sure you have a good back-up.)  And oh, the horror of having to make a complete backup such a huge disk. :-) If your data is important, make sure you have something that supports incremental backups and lots of space. (In my case, the data wasn't very important, just practical to have on-disk together.)


I am in the room with the Xerneas tree, and I keep reopening the game to find a shiny. Is it possible to find a shiny that way? If so, than will it show Xerneas shiny in the cutscene?

I want to gain some rare and valuable shinies, and I looked towards the games mascots, Yveltal, Xerneas, and Zygarde. I know in previous games (like Diamond and Pearl) you could soft reset the game until the game would give you a Shiny in for the legendary. Can you still do this?


If a  uses the Touch attack:  Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 10 (2d6 + 3) fire damage. If the target is a creature or a flammable object, it ignites. Until a creature takes an action to douse the fire, the target takes 5 (1d10) fire damage at the start of each of its turns.  And then hits a creature twice, how would the emphasized text work? Would the creature have two instances of it and take 2d10 damage at the start of the turn or only one? If they would have it twice would they be able to put both out by dousing the fire?

In the chapter on Spellcasting, there is a section called . However, despite the seeming generality of the title, the text of this section only talks about magical effects from spells:     The effects of different spells add together while the durations of those spells overlap. The effects of the same spell cast multiple times don't combine, however. Instead, the most potent effect--such as the highest bonus--from those castings applies while their durations overlap, or the most recent effect applies if the castings are equally potent and their durations overlap.   It makes sense that this section would only talk about spells, since it is in the chapter about spellcasting. However, this seems to leave ambiguous the question of how magical effects from sources other than spells combine. Such an issue could arise, for example, if two different items (or two of the same item) grant a bonus to attack rolls, or a bonus to the same saving throw.  Is there a published rule or official ruling that governs how non-spell magical effects combine?  (This question was inspired by  about the interaction between +X magical ammunition and Oil of Sharpness, and could be considered a generalization of that question.)


Is there a stackexchange site, or subsection on each site, dedicated to people who need to purchase something, but don't know the best option for their requirements?  I'm thinking of "I want to do a task using a cheap computer, requires living outside so must be waterproof and cannot be bigger than a lunchbox, looking for suggestions?"  Such a system could be used by people to be shown many options which may fit the requirement, each option being able to be up-voted just like the existing sites on stackexchange.  Note to downvoters: Please leave a message as to why. As mentioned in the comments (@Fish Below the ice) such an experiment is already happening with regards to software.

Stuff like polls, recommendations based on subjective constraints, puzzles, webcomics etc. do not belong on the serious main SE sites, where professionals should be considered at work and having just a few spare minutes ("code's compiling") to answer questions, so they should not be distracted by such things. However, I'd also like to have a home for these things still using the SE engine. For the reason I mentioned before, this needs to be a separate place though. Let's call it four.[sitename-here].com.


I have a laptop that the internal HDD is dead in. My question is how would I install Ubuntu on a new external HDD and have the laptop boot from it without an internal drive being installed. I've looked at other questions and while some are similar, I havent found anything that exactly matches. I mainly want to use Ubuntu to run Wine so I can play World of Warcraft from a private (legal) server. Thank you in advance.

OS: Windows 7. I want install Linux Ubuntu on portable external Hard Drive USB 2.0. I read a variety of methods, but I'm confused by contradictory advices and methods. Actually, installing Ubuntu on anything other than clean PC looks much more complicated than installing Windows. I need to have Ubuntu package + Python 2.7 + C compiler installed. My external hard drive is partially filled, I need to keep all files.   Will Ubuntu run entirely on external hardrive, without writing anythinhg to Windows system folders and to registry?  Can anyone post detailed guide how install Ubuntu on external hard drive?


I would like to copy all files with a certain extension that are in sub directories to a different folder. I don't want to maintain the directory structure, I just want to copy all files found to a different folder.  I used this command to do it:  cp `find . -name "*.aac"` /media/moasad/New\ Volume/Media\ files/Avengers/Aud/aac/   However, I noticed that If it runs into folders or files with spaces in them the cp function doesn't know what to do and I get an error something like this:  cp: cannot stat ‘./Temporary_Items/martin/Problem’: No such file or directory cp: cannot stat ‘Files/nav-YCA136843.aac’: No such file or directory   Notice that its one file: ./Temporary_Items/martin/Problem Files/nav-YCA136843.aac  But because of the space in "Problem Files", it's confused.

I have a script which searches all files in multiple subfolders and archives to tar. My script is   for FILE in `find . -type f  -name '*.*'`   do if [[ ! -f archive.tar ]]; then    tar -cpf archive.tar $FILE else    tar -upf archive.tar $FILE  fi done   The find command gives me the following output  find . -type f  -iname '*.*' ./F1/F1-2013-03-19 160413.csv ./F1/F1-2013-03-19 164411.csv ./F1-FAILED/F2/F1-2013-03-19 154412.csv ./F1-FAILED/F3/F1-2011-10-02 212910.csv ./F1-ARCHIVE/F1-2012-06-30 004408.csv ./F1-ARCHIVE/F1-2012-05-08 190408.csv   But the FILE variable only stores first part of the path ./F1/F1-2013-03-19 and then the next part 160413.csv.  I tried using read with a while loop,   while read `find . -type f  -iname '*.*'`;   do ls $REPLY; done   but I get the following error  bash: read: `./F1/F1-2013-03-19': not a valid identifier   Can anyone suggest an alternative way?  Update  As suggested in the answers below I updated the scripts  #!/bin/bash  INPUT_DIR=/usr/local/F1 cd $INPUT_DIR for FILE in "$(find  . -type f -iname '*.*')" do archive=archive.tar          if [ -f $archive ]; then         tar uvf $archive "$FILE"         else         tar -cvf $archive "$FILE"         fi done   The output that i get is  ./test.sh tar: ./F1/F1-2013-03-19 160413.csv\n./F1/F1-2013-03-19 164411.csv\n./F1/F1-2013-03-19 153413.csv\n./F1/F1-2013-03-19 154412.csv\n./F1/F1-2012-09-10 113409.csv\n./F1/F1-2013-03-19 152411.csv\n./.tar\n./F1-FAILED/F3/F1-2013-03-19 154412.csv\n./F1-FAILED/F3/F1-2013-03-19 170411.csv\n./F1-FAILED/F3/F1-2012-09-10 113409.csv\n./F1-FAILED/F2/F1-2011-10-03 113911.csv\n./F1-FAILED/F2/F1-2011-10-02 165908.csv\n./F1-FAILED/F2/F1-2011-10-02 212910.csv\n./F1-ARCHIVE/F1-2012-06-30 004408.csv\n./F1-ARCHIVE/F1-2011-08-17 133905.csv\n./F1-ARCHIVE/F1-2012-10-21 154410.csv\n./F1-ARCHIVE/F1-2012-05-08 190408.csv: Cannot stat: No such file or directory tar: Exiting with failure status due to previous errors


Is the group $U(\mathbb{Z}_{54}) = \{1,5,7,11,13,17,19,23,25,29,31,35,37,41,43,47,49,53\}$ a cyclic group? If so, how do I show this? This group was found as a group of units of the monoid $\mathbb{Z}_{54}$.

I'm trying to show that the group $U(Z_{54})$ is cyclic.  To start, I found the divisors of 54 = {1, 2, 3, 6, 9, 18, 27, 54}  Then I started to find the elements using the powers of a.  Where $U(Z_{54})= <a>$  Therefore, $<a^{54/1}>$={ e }  $ <a^{54/2}>$= { e, $ a^{36}$ }  and such, where the last would be < $a^{54/54}$> = { e }  The things I would like to know is, how does this process show that it's cyclic? Is it because the first divisor (1) and the last divisor (54) is equal to e? Therefore creating a cycle?  Also, what would the < a > to the powers finding the elements process be called?  Thank you!


Show that the image of the function $f:(0,\infty)\rightarrow \mathbb{R}$, $f(x)=x+\dfrac{1}{x}$ is the interval $[2,\infty)$.   If $x=1$, then $f(1)=2$. So how can I show that the mage of the function is the interval $[2,\infty)$?

I was asked to prove that:   $$x + \frac{1}{x}\geqslant 2$$  for all values of $ x > 0 $  I tried substituting random numbers into $x$ and I did get the answer greater than $2$. But I have a feeling that this is an unprofessional way of proving this. So how do I prove this inequality?


Hope you are doing well  i am facing issue while adding object to ArrayList i need your kind assistance in solving this problem each time when i am going to add something to selectedContacts ArrayList i got nullPointerException  ArrayList<ContactInfo> selectedContacts = new ArrayList<>();     public ArrayList<ContactInfo> getSelectedContacts()         {             int i = 0;             while (contacts.get(i).isCheck()==true)             {                 ContactInfo info = contacts.get(i);                 if(info != null)                     selectedContacts.add(info);                 i++;             }             return selectedContacts;         }   ContactInfo.Java  public class ContactInfo {     String name;     String number;     String email;     boolean check;      public String getEmail() {         return email;     }      public void setEmail(String email) {         this.email = email;     }      public void setCheck(boolean check) {         this.check = check;     }      public void setName(String name) {         this.name = name;     }      public void setNumber(String number) {         this.number = number;     }      public boolean isCheck() {         return check;     }      public String getName() {         return name;     }      public String getNumber() {         return number;     }  }

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


Let $\tau$ be the usual metric topology on $\mathbb{R}$. Consider the partition $\{\mathbb{Z}\}\cup\{\{x\}: x\in \mathbb{R}\setminus\mathbb{Z}\}$.  Equip this space with the quotient topology.   The question is asking to show if the quotient map is open (resp. closed) and also if the quotient space is first countable.  I have managed to show that the quotient map, $f$, is not open since $f^{-1}(f(0,2)) = (0,2)\cup\mathbb{Z}$. But $(0,2)\cup\mathbb{Z}$ is clearly not open in $\mathbb{R}$ so $f(0,2)$ is not open in the quotient space.  However the quotient map is closed since $f^{-1}(f(K))$ is either $K$ itself (and so closed in $\mathbb{R}$) or $K\cup \mathbb{Z}$ (also closed in $\mathbb{R}$). So every closed image is closed in the quotient topology.  However, I am not sure how to show if the quotient is first countable (that is, has a countable nhood-base). How can I do this? If the quotient map were open, then is would be easier.

I was searching for an easy example of a quotient space $X/{\sim}$ which is not second countable even though $X$ is second countable. I have found an example in the following answer, but I do not quite understand it:      Let $X:=\mathbb{R}$ and consider the equivalence relation $\sim$ defined by $x\sim y \Leftrightarrow x=y \text{ or }x,y\in\mathbb{Z}$.  Now it is claimed that the space is not first countable at the point $[0]\in X/{\sim}$. Why is this the case? I would be very glad, if someone can explain it to me in more detail.


I have the .deb file of the newest version of PlayOnLinux and I can run it with no problems if I just double click it, but when I run it from terminal it gives an error and the program doesn't start. Here is the command line output: ~$ ./Games/PlayOnLinux_4.3.4.deb  ./Games/PlayOnLinux_4.3.4.deb: line 1: syntax error near unexpected token `newline' ./Games/PlayOnLinux_4.3.4.deb: line 1: `!<arch>'  The file is already tagged as executable in the properties. Can someone help me with this?

How do I install a .deb file via the command line?


we have a new feature annoucement pop up which comes once to the user on our dashboard. when we speak about new feature it is ideal to show the the demo video as well i feel. so we have inluded a video pop up over the main pop up. Is this is right way of doing? or is this against the laws of good UX?

I'm newbie when it comes to UX, there's a thing I don't understand and couldn't find answer to that. So I hear every now and then that modal on modal is bad. But I don't understand why and no one could explain it to me so far.   For example: We have web application where you can work on a document and you can invite people. Inviting people opens modal - it's self contained flow of permission management. You can invite, remove and change permissions of users. If you start changing permissions or removing people then you need to press "Save" button to confirm it all. If you try to leave modal without confirming then another small modal "You have unsaved changes, do you want to proceed?" is displayed. So I heard people saying this is "bad UX/bad solution", but why? This is exactly what Google implemented in their Google Docs. What would be "good UX" then?


I'm looking for this question in MSE. But,I could not find a similar one.     Is ${x+\dfrac 1x}$ equal an integer number, only $x=1$ ?   If, $x>0$.   I can prove this only when $x\in \mathbb{N}$ but not for $x \in \mathbb{R}^+$.  Remark: the duplicate link just answer the case where $x \in \mathbb{Q}$.

Can sum of a rational number and its reciprocal be an integer?   My brother asked me this question and I was unable to answer it.   The only trivial solutions which I could think of are $1$ and $-1$.  As to what I tried, I am afraid not much. I have never tried to solve such a question, and if someone could point me in the right direction, maybe I could complete it on my own.  Please don't misunderstand my question.   I am looking for a rational number $r$ where $r + \frac{1}{r}$ is an integer.


My external hard drive fell down two days ago and since then, if i connect it to my computer it would not be visible. it stopped spinning but making funny beeps. i'll be very glad if anyone can assist me.

What steps can I take to try to recover lost or inaccessible data from any storage device?  Answers:   This applies to any computer storage device, e.g. internal/external hard drives, USB sticks, flash memory. The most important thing is to STOP using it, any type of I/O can ruin your chances of a recovery.     We have separate questions covering common problems with USB flash drives in greater detail:


I really want to fight Plantera, because I have all the gear and stuff. But there's one problem; I don't know how to summon it. What do I have to do to summon Plantera?

I have been playing on hardmode for a while and have beaten the three  a couple of times. But I have yet to find a . It's getting really frustrating.  Does anyone have any methods to finding a Plantera Bulb?


I want implement a function in c++ which returns the minimum of an array of any type. My code for now looks like this:  main.cpp:  #include <iostream> #include <bits/unique_ptr.h> #include "MathHelper.h"  using namespace std;  int main() {     std::array<int, 3> myarray = {10,20,30};     int i = MathHelper::minimum(myarray);     printf("%d\n", i);     return 0; }   MathHelper.h:  #ifndef OPTIMIERUNG_MATHHELPER_H #define OPTIMIERUNG_MATHHELPER_H   #include <stddef.h> #include <array>  class MathHelper { public:     template <typename T, size_t SIZE>      static T minimum(std::array<T, SIZE>& a);  };   #endif //OPTIMIERUNG_MATHHELPER_H   MathHelper.cpp:  #include "MathHelper.h"  template<typename T, size_t SIZE> T MathHelper::minimum(std::array<T, SIZE> &a) {     int minimum = a[0];     if(SIZE>0){         for(size_t i=1;i<SIZE;i++){             if(a[i] < minimum){                 minimum = a[i];             }         }     }     return minimum; }   executing this program results into following exception:  undefined reference to `int MathHelper::minimum<int, 3ul>(std::array<int, 3ul>&)'

Quote from :     The only portable way of using templates at the moment is to implement them in header files by using inline functions.   Why is this?  (Clarification: header files are not the only portable solution. But they are the most convenient portable solution.)


I am currently using OpenID connected with a Yahoo email address. I want to create a normal Stack Exchange account and connect it with my current account. I don't want to use Yahoo OpenID any more. Is it possible?  I could not find a way to do it.

When I started using Stack Exchange sites several years ago, I logged in using Google since I wasn't sure I wanted yet another login. Well, at this point I value my Stack Exchange identity more than my Google identity, and I'd like to sever the connection.  I know you can add logins in the My Logins section of your settings, but I don't see a way to "add" the Stack Exchange login option I see in the new sign up screen.  Can this be done?


In my High school the network (local network with printers and file server + internet access) is using Active Directory for authentication. If I want to print/access the file servers with Ubuntu I need to authenticate against the AD. Guess I'll use Samba but how exactly do you do that? Many thanks :)

We have a "mix-mode" Lab. and we want to migrate to Ubuntu, from Windows.  In this process, how do we add Ubuntu workstations to a Windows Domain / Active Directory ('AD') setup?


So i was messing around with some settings but I don't know what i did to do this. Whenever I add like a plane for example, it is always facing towards wherever I am instead of straight up like it normally would. Anyone know the setting that does this?

I was following a tutorial on blender ( I dont remember which now, as I have watched a lot ). I some how  set up this feature and now I dont know how to turn it off.   Each time I apply an object in to my scene, it applies facing whichever direction my camera is facing. How can I get this back to the default of applying the object in the center?  Thank you in advance.


If I had a very strong magnet on Earth and a very sensitive compass on Mars (just using planets to illustrate large distance), how long would the compass take to notice if I turned the magnet 180deg?  I assume it can't beat the speed of light.  Do the outer reaches of the magnetic field move as a rigid body with the turning magnet or do they lag in motion?

Does magnetic propagation follow the speed of light? E.g. if you had some magnet of incredible strength and attached an iron wire that is one light year long to it, would the other end of the iron wire begin to show a magnetic field in a year, or could it possibly be faster than a year?


I'm self-studying Rudin's Principles of Mathematical Analysis, and making an attempt to prove the theorems in the book myself before reading how they're done. I'm stuck on Theorem 2.43: Let $P$ be a nonempty perfect set in $\mathbb{R}^{k}$. Then $P$ is uncountable. I think I understand what perfect means (that a set is made entirely up of and contains all its limit points), and I understand that I need to show that no bijection exists between the set of elements of $P$ and the positive integers. I considered trying to find a surjection from the set of points in $P$ to the set of all integer sequences or the set of all sequences made up of 0 and 1, as well as from $P$ to some subset of the real number line, but I can't figure out how to go about actually proving the result I need. Maybe there's a connection to compact sets I'm missing? Any small hints would be appreciated (I still am hoping to have some of the fun of finding an answer).

There is something I don't understand about the proof that . The same proof is present in Rudin's Principles of Mathematical Analysis.  Do we assume that our construction of $U_n$ must contain all points of $S$? What if we are only collecting evenly-indexed points of $S$ ($x_{2n}$)? We would still get an infinitely countable subset of $S$, and the rest of $S$ can be used to provide points for $V$. What am I missing?


I am having another problem with one of my div containers. I tried every way to fix it but couldn't see the issue so this is why I am posting here again.  I have a big div container that has another 3 divs inside , and I can't find a way to center the big div...  Hope I pasted the html and css codes right , it gets confusing when I have to tap on space for each line lol

             Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do              eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut              enim ad minim veniam, quis nostrud exercitation ullamco laboris              nisi ut aliquip ex ea commodo consequat.

Placeholder_Name

             Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do              eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut              enim ad minim veniam, quis nostrud exercitation ullamco laboris              nisi ut aliquip ex ea commodo consequat.

Placeholder_Name

             Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do              eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut              enim ad minim veniam, quis nostrud exercitation ullamco laboris              nisi ut aliquip ex ea commodo consequat.

Placeholder_Name

   ----CSS---- .section3 {   width:50%;   height:500px;   background-color:#adaba7; }  .section3Container {   margin-top:50px;   }  .person {   width:30%;   float:left; }  .person img {   display:table;   margin:0 auto;   margin-bottom:30px;  }  .person h4 {   text-align:center; }  blockquote{   text-align:center;   font-size:15px;   font-style:italic;   color: #555555;   padding:17px 15px;   border-left:8px solid #b19530;    position: relative;   background:#e2e1dc;   border-radius:50px;   margin-bottom:20px;  }  blockquote::before{   content: "\201C";   color:#b19530;   font-size:4em;   position: absolute;   left: 10px;   top:-10px; }  blockquote::after{   content: ''; }

How can I horizontally center a
 within another
 using CSS?

Foo foo


I want to prove that: the integral domain $k[x,y]/ (x^3 - y^2)$ is not normal and find its integral closure in its field of fractions. I know that I will use the idea that $UFD \implies$ normal and hence not normal means not $UFD$ so what I should show is that $k[x,y]/ (x^3 - y^2)$ is not a UFD and I have read a hint here  to consider $x = (y/x)^2.$but I can not see how that will show that it is not a UFD. could someone elaborate this to me please? Also, what is the field of fraction of this integral domain? I know that a unique factorization domain is an atomic integral domain in which factorization to irreducibles is unique (up to associates). And a commutative ring is atomic if each $r \in R$ is a finite product of irreducibles in R. Also, a ring $R$ is a normal ring if $R$ is an integral domain that is integrally closed in $\operatorname{frac}(R).$ And $R$ is integrally closed in a commutative ring $S$ iff the integral closure of $R$ in $S$ (int($R$)) equals $R$. And int($R$) consists of all $x \in S$ that is integral over R. And note that an element is integral over $R$ if there exists a monic polynomial $f(x) \in R[x]$ such that $f(x) = 0.$

I'm trying to show that $R = \mathbb{Q}[X,Y]/(Y^2-X^3)$ is not a UFD, but I got stuck.  To prove this, I could try to find two "different" factorisations for one element, but I am not familiar with this, so I tried to use a lemma and one of the previous exercises. If my syllabus is right, in every UFD counts $$ x \ \text{is irreducible} \quad \iff \quad x \ \text{is prime}$$ My syllabus also states that the elements $\bar{X}, \bar{Y} \in R$ are irreducible. So I tried to show that at least one of the elements $\bar{X}, \bar{Y} \in R$ does not generate a prime ideal.  This would mean that I should find two polynomials $f,g \in \mathbb{Q}[X,Y]$, such that  $$\exists p \in \mathbb{Q}[X,Y], \quad fg - pX \in (Y^2-X^3)$$ and $$\forall q \in \mathbb{Q}[X,Y], \quad f-qX \notin (Y^2-X^3) \ \wedge \ g-qX \notin(Y^2-X^3)$$ or the same thing but then for $Y$.  I hope that you can tell me if this approach is correct, and provide me a hint. I'd appreciate it if you told me the solution, but please start your answer with a hint, clearly separated from the rest.


I have to prove: $||x|-|y||\leq |x+y|\leq |x|+|y|$ I have already proved $|x+y|\leq |x|+|y|$.  I saw proofs for $||x|-|y||\leq |x-y|$, can I use the proof for  $||x|-|y||\leq |x-y|$ and just add that $|x-y|\leq|x+y|$?

I've seen the full proof of the Triangle Inequality  \begin{equation*} |x+y|\le|x|+|y|.  \end{equation*} However, I haven't seen the proof of the reverse triangle inequality:  \begin{equation*} ||x|-|y||\le|x-y|. \end{equation*} Would you please prove this using only the Triangle Inequality above?  Thank you very much.


I am in the process of setting up a few servers -- Right now we are switching from a managed to un-managed solution. My requirements are "set up web servers" -- check ... "Set up data servers" -- check ... Set up DNS servers .... hmmmmm  Now I am no noob with Linux, and I've even messed around with bind -- But I have been searching all over and can't get a thorough grasp start-to-finish. I'd like to be able to discuss somewhere what my exact needs are, and have possibly have someone either explain what I need, or point me to references that will explain what I need to do.  I know to some this might sound silly, but I've been all over searching, and the information out there is overwhelming. This is a case of too much information can be a bad thing when you need to sift through it all and figure out what you need... The difficult part is, I don't know which information I need! Which Stack Exchange site is the best place for this specific question?!

Where should I post question like:     Where can I find books on [some programing subject]?   or      Online sources for learning  [some programing technique]?   ? ? Should it be community wiki? or is it a taboo in the ?


I am wondering if it is possible to check the existence of a function within a script. I.e. at the moment, I have a few if's to check a value and then call a function, but was wondering if it is possible to do something like:  if[[ ${function_name}Function exists ]] then .....call function etc fi   where there may be a function within the script  Is this possible?

Currently I'm doing some unit tests which are executed from bash. Unit tests are initialized, executed and cleaned up in a bash script. This script usualy contains an init(), execute() and cleanup() functions. But they are not mandatory. I'd like to test if they are or are not defined.  I did this previously by greping and seding the source, but it seemed wrong. Is there a more elegant way to do this?  Edit: The following sniplet works like a charm:  fn_exists() {     LC_ALL=C type $1 | grep -q 'shell function' }


I need help finding the covergence radius of $\sum_{n=1}^\infty n! x^{n!}$ .  The factorials make me think that I need to use derivatives/ integrals but I don't quite know how.  I'd love any help, thanks.

Find the radius of convergence of $\sum_{n=1}^{\infty}{n!x^{n!}}$. Should I look at this series as: $\sum_{n=1}^{\infty}({n!x^{(n-1)!})x^{n}}$? I am really confues here. In addition, any attempt to compute any kind of "lim sup" fails. I would appreciate your help in this.


I am writing a report and I want to place a big sidewaystable inside an appendix. More specifically, this appendix does not contain anything else but the table.  \newpage\begin{appendices}  \section{References} %\addcontentsline{toc}{section}{References}  \bibliographystyle{IEEEtran} \bibliography{bibliography}  \newpage \section{Pitch - Frequency Table} \label{pitchfrequency} \begin{sidewaystable}[htbp!] \begin{tabular}{|l|c|c|c|c|c|c|c|c|c|c|c|c|}   ...a lot of cell data... \end{tabular} \caption{Something.} \end{sidewaystable}  \end{appendices}   I want the result to be one page for the appendix Pitch - Frequency Table, consisting of the appendix name and the table. However, the above code creates two pages, one for the appendix name and one for the sideways table. Any tips?  These are the two pages shown in Overleaf:    THIS CAN BE REPRODUCED HERE:

I want to rotate a table because it is too wide. I'm forced to use \documentclass[11pt,a4paper]{article}, so changing that is not a solution.  Many packages rotate the whole page, but I just wan't to rotate the table.  I have a design sample of a table, that I must use. In my tex code that is my first table.   The second snippet is how I can rotate a table. Yet I'm missing a required caption on the table.   The third snippet is what I actually want, but I'm getting a LaTeX Error: Not in outer par mode . I found a similar question  but the answer provided a solution with sidewaystable and that is just plain ugly in my case, because then the rotated table occupies a whole page on its own.  \documentclass[11pt,a4paper]{article} \usepackage[graphicx]{realboxes} \usepackage{verbatim} \begin{document} \begin{table}[htb] \begin{center} \begin{tabular}{|l|c|c|c|c|c||c|c|c|c|c||c|c|c|c|c|} \hline \bf Some text & \rotatebox{90}{column 1  } &  \rotatebox{90}{column 2} & \rotatebox{90}{column 3  } & \rotatebox{90}{column 4 } & \rotatebox{90}{column 5 }  & \rotatebox{90}{column 6  } &  \rotatebox{90}{column 7} & \rotatebox{90}{column 8 } & \rotatebox{90}{column 9 } & \rotatebox{90}{column 10 } & \rotatebox{90}{column 11 } &  \rotatebox{90}{column 12} & \rotatebox{90}{column 13 } & \rotatebox{90}{column 14  } & \rotatebox{90}{column 15 }\\ \hline \hline first row lorem ipsum & 692 & 535 & 85 & 48 & 24 & 692 & 535 & 85 & 48 & 24 & 2 & 3 & 3 & 4 & 5 \\ \hline \end{tabular} \end{center}  \caption{My caption lorem ipsum}\label{tab_aaa} \end{table}   %rotated \rotatebox{90}{ \begin{tabular}{|l|c|c|c|c|c||c|c|c|c|c||c|c|c|c|c|} \hline \bf Some text & \rotatebox{90}{column 1  } &  \rotatebox{90}{column 2} & \rotatebox{90}{column 3  } & \rotatebox{90}{column 4 } & \rotatebox{90}{column 5 }  & \rotatebox{90}{column 6  } &  \rotatebox{90}{column 7} & \rotatebox{90}{column 8 } & \rotatebox{90}{column 9 } & \rotatebox{90}{column 10 } & \rotatebox{90}{column 11 } &  \rotatebox{90}{column 12} & \rotatebox{90}{column 13 } & \rotatebox{90}{column 14  } & \rotatebox{90}{column 15 }\\ \hline \hline first row lorem ipsum & 692 & 535 & 85 & 48 & 24 & 692 & 535 & 85 & 48 & 24 & 2 & 3 & 3 & 4 & 5 \\ \hline \end{tabular} }  \begin{comment} %% what i want \rotatebox{90}{ \begin{table}[htb] \begin{center} \begin{tabular}{|l|c|c|c|c|c||c|c|c|c|c||c|c|c|c|c|} \hline \bf Some text & \rotatebox{90}{column 1  } &  \rotatebox{90}{column 2} & \rotatebox{90}{column 3  } & \rotatebox{90}{column 4 } & \rotatebox{90}{column 5 }  & \rotatebox{90}{column 6  } &  \rotatebox{90}{column 7} & \rotatebox{90}{column 8 } & \rotatebox{90}{column 9 } & \rotatebox{90}{column 10 } & \rotatebox{90}{column 11 } &  \rotatebox{90}{column 12} & \rotatebox{90}{column 13 } & \rotatebox{90}{column 14  } & \rotatebox{90}{column 15 }\\ \hline \hline first row lorem ipsum & 692 & 535 & 85 & 48 & 24 & 692 & 535 & 85 & 48 & 24 & 2 & 3 & 3 & 4 & 5 \\ \hline \end{tabular} \end{center}  \caption{My caption lorem ipsum}\label{tab_b} \end{table} } \end{comment} \end{document}   How can I add a caption to the second snippet?


I am struggling to import a figure.SVG in Overleaf. I tried with \usepackage{svg}  but it doesn't work. I read a few times about Inkscape, however I work on Overleaf and I have no idea how to install Inkscape. Could someone give me some instructions. Thanks I try to reformulate my question. I draw a diagram on draw.io and inserted also some math-notations (Q_dot and subscripts). If I export the file as a .svg and inport it in my latex document the Math notations are gone! See on the screenshot  On top of that do I get the error "Viewer does not support full SVG 1.1" Is there a way to import .svgfiles without getting any losses in the math notation? I tried also to convert the .svginto a .pdfhowever do I get the same problem. how are figures with Math notations normally imported into a LaTeX file?

Unfortunately I am not able to include svg images in overleaf. This is the minimal example: \documentclass{article} \usepackage{svg} \usepackage{amsmath} \begin{document}  \begin{figure}[htbp]   \centering   \includesvg{image.svg}   \caption{svg image} \end{figure}  \end{document}  This will give an error says File `./image' not found  Overleaf does allow svg extensions but how can I include the file?


I have installed Lubuntu on an old Dell D600 laptop. Everything is working great except for the wireless Ethernet card.  "lspci -vnn -d 14e4:" reveals the following:  ~~~~~  Broadcom Corporation BCM4309 802.11abg Wireless Network Controller [14e4:4324] (rev 02)  ~~~~~  Somebody recently (Sept 5th) posted the answer for a card very similar to this (all the same except for the "rev 02" part) - and in their answer they stated something similar to "You have a 50% chance of having the other (rev 02) version of this wireless card - if it turns out you have that one, post back again for recommendations relevant to that".  Apparently the other question-asker did not have the "rev 02" version, as they did not post back again.  I'm hoping either the person posting that answer or somebody else here could post their recommendations for the "rev 02" version of this card.  Regards.

I'm having serious problems installing the Broadcom drivers for Ubuntu. It worked perfectly on my previous version, but now, it is impossible.   What are the steps to install Broadcom wireless drivers for a BCM43xx card?  I'm a user with no advance knowledge in Linux, so I would need clear explanations on how to make, compile, etc.    lspci -vnn | grep Network showed:   Broadcom Corporation BCM4322 802.11a/b/g/n Wireless LAN Controller [14e4:432b]      iwconfig showed:  lo        no wireless extensions. eth0      no wireless extensions.   NOTE: Answer below is updated every time new information is added and confirmed working.


I am new to windows environment and am trying to set up an AD and Domain controller  Are an Active Directory domain and a DNS domain technically referring to the same thing? Must they be the same at all? e.g. if my DNS domain is "company.com", must my AD domain be "company.com" too?  Reason for asking this question is because of the following observation   I have seen workstations join Domains that I am quite sure are not actually valid domain names (e.g. xxx.local) I have seen 2 different domain controllers in 2 different network with different server hostname/domainname (FQDN) e.g.      dc1.brancha.com,   dc1.branchb.com   allowing workstations in their own network to login to the same active directory domain (xxx.local) which is totally not related to the server DNS domain name.  Am I missing something ?

This is a  about Active Directory domain naming.   After experimenting with Windows domains and domain controllers in a virtual environment, I've realized that having an active directory domain named identically to a DNS domain is bad idea (Meaning that having example.com as an Active Directory name is no good when we have the example.com domain name registered for use as our website).   , but I'm still not sure about what other rules there are around naming Active Directory domains.  Are there any best practices on what an Active Directory name should or shouldn't be?


Now quotes look like that:     A quote.   Quote's style changed. Is it a bug or just style update?

Update  Sorry for the delay! I’ve been thinking about this feedback in between my other projects, and I’ve landed where I’ve started 😕  I’ve made sure to continue highlighting spoilers in gray. The differentiation from normal blockquotes is super important since their behavior is so different. I explored keeping spoilers yellow, but that still has the same theming issues throughout the network. Red seemed too powerful, with its error connotations.  I understand completely that folks are using blockquotes to highlight images. However, I don’t think that’s a  we want to formally pave. I’m ok with being opinionated here—blockquotes should be used for quoting, not as a way to highlight images. I understand that this will be frustrating to Machavity who made excellent points about differentiation in his answer, but I don’t think image highlighting ought to dictate how blockquotes are styled.  I’m also cautious of adding borders to images as explored by user1306322 for the same reasons and for the additional fear of being too prescriptive in how we display images there.  It’s a tough one! I went back and forth with the design team and I still think this is the best path forward.  Original post  We’re making a few changes to blockquotes soon. Historically, we had a bit of feedback that the yellow backgrounds were overpowering, reducing the contrast of the quote itself. The yellow border also lacks contrast with the background. Others have indicated that there should be  and between .  These yellows also compete with theming in our communities, especially those with backgrounds that aren’t perfectly white like English Language & Usage and Role-Playing Games.   We’re proposing we switch to a single gray bar in our blockquotes. This should fix those theming issues and make it easier to distinguish between quotes, spoilers and code.  This will also improve blockquote nesting, since our current nesting is a mess because the darker yellow bar is barely noticeable on the paler yellow background.  Spoilers should pretty much behave exactly the same way. More room for later improvements there.  Here’s how our current blockquotes look. You can click to expand:    Here’s what we propose:    There is a lot of prior art out there for this approach. GitHub has styled theirs this way for a long time. So has Slack.     Let me know what y’all think. I think these changes will be an improvement, and I hope you do too.  Huge thanks to Catija for gathering some meta posts on blockquotes and creating an awesome blockquote playground post for testing.


Y is the dependent variable with the outcome 0 and 1, and so are X1...X140. As far as I know, I can't use the simple lasso regression in order to look at which variables are shrinked down, since we got only binary data.   We also got perfect linear independence, where for example X1 stands for male and X2 for female.  Furthermore, I want to do a cross validation, in order to determine which lambda value is the best.   I was reading, that some people suggested to use grouped lasso regression, but wouldn't a logistic lasso regression be more appropriate? I'm using glmnetand the caret packages, but I couldn't find in the documentation, which solves my problem. Which packages do you know, who can deal with those problems?

Is it possible to conduct a regression if all dependent and independent variables are categorical variables?


I'm planning to get a paperless office and for that, I a need good scriptable piece of OCR for OS X?  I've read a  by Marco Arment about a few programs. Are there any workable ones there that allow me to script things?

I am looking for an offline scriptable tool that makes an existing PDF file searchable by running OCR on it, replacing the original non-searchable file with the searchable version, and can run unattended.  E.g., www.pdfscannerapp.com - does exactly what I need, but it's GUI only - not scriptable.  I am aware that Evernote makes PDF files searchable, but they remain searchable only when within Evernote.  I am not looking for perfect OCR, even a moderately acceptable OCR is fine, but I would prefer a small utility rather than a bulky software package.  (I am aware of a similar, but different question on AD:  - however, I don't need to sign or fill PDFs, and my requirement is that the solution is scriptable)  EDIT:   1) Several utilities allow structured text extraction, however in order to be extracted, the text must be there; I am mainly referring to PDFs that are wrapped bitmaps, as is the case with plain PDFs generated by scanners.  2) I am not necessarily looking for a free solution, and I would be more than happy to pay for a good utility that just does what I need, but I am not looking for bulky applications with a million features that include an OCR feature but whose cost does not justify buying them just for the OCR functionality.  3) As stated above, I am not looking for perfect OCR, just a moderately acceptable OCR. Unfortunately, in my experience, tesseract is really below that threshold. I define "moderately acceptable" an OCR that can, say, OCR an utility bill so that at least the account number (customer number) is recognized correctly.  EDIT: "scriptable" or "automatable", that is, able to be triggered automatically and run unattended without human input whatsoever.


I am trying this math to solve.the equation is like this:  $2^x=4x$  Here $x=4$ should be the answer.  But How can I derive it in a mathematical way?  I am failed to solve it my general algebra.How can I use logarithm here to solve it?  Thanks in Advance.

Given that $x$ is a positive integer. By using methods of trial and error as well as plotting two lines: $y=2^x$, $y=4x$ on a graph and find their intersection point, we can easily solve for $x$ which is equal to 4. However, I do not know how to solve this using only equation. Can anyone help me?


How do the following options differ in what they imply?  Option 1  The real question is: what do you want to achieve?  Option 2  The real question is, "What do you want to achieve?"  Is there an existing convention for this pattern? If so, what is it? My options are specifically quotes and colons.

I came across this sentence at . Why is "Does" capitalized?     The question is, Does anyone support this legislation?


I have a lot of object in my BGE environment. I can select them easily by using regular expression. All of them, also have action with specific name, too. Now I want to add them to my game, by python script. Is there any way to add actuator, controller and set action programmatically?

Is it (if at all) possible in Blender 2.6+?   If not, will future versions of Blender support it?  I see some old posts ( and ) saying that it is not possible. However, I found  referring to operators under  that allowed me to add sensors and controllers from python.  bpy.ops.logic.sensor_add(type='ALWAYS', object=my_obj.name) bpy.ops.logic.controller_add(type='LOGIC_AND', object=my_obj.name)   However I am not able to find any way to link them from python. I tried following (but did not work):  new_controller = my_obj.controllers[-1] new_sensor = my_obj.sensors[-1]   It throws AttributeError saying that object has no attribute 'controllers' :-/


I am travelling from India to Havana via Amsterdam.the layover time at Amsterdam is 1.45 hrs. Do I require to obtain Transit Visa?

I found many related questions on this site but I am still not sure about the rules. How can I decide if I need a visa to transit? Schengen members as of May 2021 are as follows:  Austria Belgium Czech Republic Denmark (excluding Greenland and the Faroe Islands - but an open border with the Schengen Area is maintained) Estonia Finland France (excluding overseas departments and collectivities) Germany Greece Hungary Iceland Italy Latvia Liechtenstein Lithuania Luxembourg Malta Netherlands (excluding Aruba, Curaçao, Sint Maarten and the Caribbean Netherlands) Norway (excluding Svalbard) Poland Portugal Slovakia Slovenia Spain (except Ceuta and Melilla) Sweden Switzerland


I have been taught that $\frac{1}{3}$ is 0.333.... However, I believe that this is not true, as 1/3 cannot actually be represented in base ten; even if you had infinite threes, as 0.333... is supposed to represent, it would not be exactly equal to 1/3, as 10 is not divisible by 3.  0.333... = 3/10 + 3/100 + 3/1000...   This occured to me while I  discussion on one of Zeno's Paradoxes. We were talking about one potential solution to the race between Achilles and the Tortoise, one of Zeno's Paradoxes. The solution stated that it would take Achilles $11\frac{1}{3}$ seconds to pass the tortoise, as 0.111... = 1/9. However, this isn't that case, as, no matter how many ones you add, 0.111... will never equal precisely $\frac{1}{9}$.  Could you tell me if this is valid, and if not, why not? Thanks!  I'm not arguing that $0.333...$ isn't the closest that we can get in base 10; rather, I am arguing that, in base 10, we cannot accurately represent $\frac{1}{3}$

I'm a PreCalculus student trying to find a rigorous proof that $\displaystyle\frac{1}{3} = 0.333\ldots$, but I couldn't find it. I think (just think) that this proof would start by proving that  $\displaystyle\sum_{i=1}^{\infty}3\cdot10^{-i} = \frac{1}{3}$. My guesses (assuming that proving that $\displaystyle\sum_{i=1}^{\infty}\left(\frac{1}{10}\right)^i$ converges is trivial):  $\displaystyle\sum_{i=1}^{\infty}3\cdot10^{-i} = 3\cdot\sum_{i = 1}^{\infty}10^{-i} = 3\cdot\sum_{i=1}^{\infty}\left(\frac{1}{10}\right)^i = 3\cdot\left(\frac{1}{1 - \frac{1}{10}}-1\right) = 3\cdot\left(\frac{10}{9}-1\right) = \frac{1}{3}$.  Questions: is this completely rigorous? Which flaws could be found in this proof? How can I improve it?  PS. I'm not sure how to tag this. Feel free to edit, if necessary.


I have a dell xps 13 running ubuntu 18.04. Laptop came with a touchscreen which is always active and i can disable with xinput. I have created a custom appication button which I added to favorites and when i click, touchscreen turns off which is very very convenient. My question is: can I further customise this desktop entry in a way that when i click it, if the touchscreen is active it turns off but if the touchscreen is disabled, it turns on... Is there any way to add a conditional statement in the xinput command? text in my dektop entry: [Desktop Entry] Name=touchscreen Comment=nada Exec=xinput -disable "ELAN2930:00 04F3:2930" Type=Application Terminal=false Icon=/home/roland/Pictures/touchscreen.png

I can disable a device like this:  xinput set-prop 13 "Device Enabled" 0   But I want to actually set a custom shortcut that toggles this between 0\1. My bash skills are kinda rusty, so how can I do this? There's no get-prop command, I got this far:  xinput list-props 13 | grep "Device Enabled"   Which correctly prints out  Device Enabled (135):   1   But I don't know what to do next. Help?


I need help with my account I accidentally deleted my primary email alias that I Been using for many years when I added a new one it used to be my old email address and now it's a different one with @gmail.com and I want it back to @ hotmail.com and I want it back as it’s registered everywhere. I tried all that I could. Please help!! It’s very important

One of my associates had their Hotmail account broadcasting spam, and presumably hacked. They managed to change the password, but after that, the account got locked; Hotmail asks you for a phone number, and they're supposed to call you with a code.  This person requested the code several times, with different numbers (even two of mine!), but never received any call with the confirmation code.  I referred them to the full-length process, which includes answering the security question; apparently, they forgot their question (having entered it over a decade ago and never reviewed it since).  What options, if any, exist to restore access to this person's account? They only want to grab their contacts; they plan to operate full-force on GMail going forward.


Consider any set $S$ which is not finite. Is it true that $S \times \mathbb{Z}$ has the same cardinality as $S$?  I thought the answer is "yes" and I thought it would be a trivial problem. But as I think about it, I have a nagging feeling it requires something like the Axiom of Choice and now, I'm not even sure the answer is "yes."  One cursory idea I had was to consider an injection of $\{s\} \times \mathbb{Z} \to S$ for each fixed $s \in S$. Somehow, if we can patch these together to form another injection $S \times \mathbb{Z}$, we would be done.

This seems evident, but I cannot come up with a reasonable proof for:  Question: show that if $X$ is an infinite set and $Y$ is a countable set, then $|X \cup Y|=|X|$


Let $A_n$ be a sequence of independent events with $$lim_{n \to \infty}P(A_n)=0.$$ Suppose that  $$\sum_{n=1}^{\infty}P(A_n^c \cap A_{n+1}) < \infty.$$ Will the events $A_n$ cease to occur eventually with probability one?  I think that the question is asking to show that  $$P(A_n\ i.o.)=0$$ And I tried to prove that $$\sum_{n=1}^{\infty}P(A_n)<\infty$$ So that I can use the Borel-Cantelli Lemma.  But I did not get nowhere. I am kind of confused about all these operations includes limits, sets, and interplays between them, as well as the $limsup$ and $liminf$ stuff. Hope someone could help me.

If $P(A_n) \rightarrow 0$ and $\sum_{n=1}^{\infty}{P(A_n^c\cap A_{n+1}})<\infty$ then $P(A_n \text{ i.o.})=0$.  How to prove this? Thanks.


My goal is to write a framework for measuring method execution or transaction time and for processing the measurements, i.e. storing, analysis etc. Transaction may include calls to external systems, with synchronously or asynchronously waiting for the results.  There already have been some questions around that topic, like    ""  ""  ""   And all the answers boil down to three approaches for taking the time   System.currentTimeMillis() System.nanoTime() Instant.now() and Duration(since Java 8)   I know, all of these have some implications  System.currentTimeMillis()  The result of this method depends on the platform. On Linux you get 1ms resolution, of Windows you get 10ms (single core) ~15ms (multi core). So it's ok for measuring large running operations or multiple executions of short running ops.  System.nanoTime()  You get a high resolution time measure, with nano second precision (but not necessarily nano second accuracy) and you get an overflow after 292 years (I could live with that).  Instant.now() and Duration  Since Java 8 there is the new time API. An instant has a second and a nano second field, so it uses on top of the Object reference two long values (same for Duration). You also get nano second precision, depending on the underlying clock (see ""). The instantiaion is done by invoking Instant.now() which maps down to System.currentTimeMillis() for the normal System clock.  Given the facts, it becomes apparent, that best precision is only achievable with System.nanoTime(), but my question targets more towards a best-practice for dealing with the measures in general, which not only includes the measure taking but also the measure handling.   Instant and Duration provide best API support (calculating, comparing, etc) but have os-dependend precision in standard case, and more overhead for memory and creating a measure (Object construction, deeper callstack) System.nanoTime() and System.currentTimeMillis() have different levels of precision but only have basic "api" support (math operations on long), but are faster to get and smaller to keep in memory.   So what would be the best approach? Are there any implications I didn't think of? Are there any alternatives?

How do you write (and run) a correct micro-benchmark in Java?  I'm looking for some code samples and comments illustrating various things to think about.  Example: Should the benchmark measure time/iteration or iterations/time, and why?  Related:


I have completed by Matrices classes and the only question that is roaming in my mind is what is this determinant actually. Like they simply told the formula and things that are to be calculated and how to calculate them.  I wanna know what these determinants actually tell about a matrix and how do they relate to them? Like we have a matrix and its determinant, how is this determinant related to it? And why do we calculate the determinant in the way we calculate it?   Like already matrix multiplication is a bit different then I expected it to be. One more thing I wanna know is why the determinant has such properties and how does it exhibit them? And how can these things be related to each other? Thanks!

In my linear algebra class, we just talked about determinants. So far I’ve been understanding the material okay, but now I’m very confused. I get that when the determinant is zero, the matrix doesn’t have an inverse. I can find the determinant of a $2\times 2$ matrix by the formula. Our teacher showed us how to compute the determinant of an $n \times n$ matrix by breaking it up into the determinants of smaller matrices. Apparently there is a way by summing over a bunch of permutations. But the notation is really hard for me and I don’t really know what’s going on with them anymore. Can someone help me figure out what a determinant is, intuitively, and how all those definitions of it are related?


I remember solving this in highschool , but now I don't remember how to find sum of these kind of series .  I want to find the sum of the general series   Sum   $\sum_{n=1}^{\infty} n .a^{-n} =  ? $  and     $\sum_{n=1}^{N}n. a^{-n} =  ? $

How can I evaluate $$\sum_{n=1}^\infty\frac{2n}{3^{n+1}}$$? I know the answer thanks to , but I'm more concerned with how I can derive that answer. It cites tests to prove that it is convergent, but my class has never learned these before. So I feel that there must be a simpler method.  In general, how can I evaluate $$\sum_{n=0}^\infty (n+1)x^n?$$


I don't see a method built in the existing php sdk to add or remove subscriber from the auto suppression list, can somebody please share the same if you have it developed

How do we delete subscribers (emails) from Auto suppression list using SSJS. Also, Auto suppression list maintain at SF end or application level.


At the end of Star Wars: Episode III while Obi-wan and Anakin are fighting, Obi-wan gains the high ground and tells Anakin that the fight is over because of it.  What? The high ground has made no difference in any lightsaber fight for 3 movies. Why would Obi-wan declare himself the victor because of this?    Note: I'm not asking why Obi-wan won; that's already been answered in other questions. I'm asking why Obi-wan believed he would win for something as insignificant as having the higher ground.

In the climactic scene, where Obi-Wan and Anakin are dueling with their light-sabres across a wide range of platforms (moving rafts, on precarious ledges etc) without the slightest awkwardness - why is it that when Obi-Wan got a slightly higher ground than Anakin (and even explicitly pointed this out), did Anakin lose the fight so spectacularly?   Anakin could have   Walked/run up the incline Used his Jedi powers to engage Obi-Wan at a distance Do a host of other things, instead of leaping in a way that would make him a sitting duck   I'm just curious: having a "high ground" generally makes for an advantage for "normal" battles involving projectiles (an arrow fired with the same force would cover more distance from a higher position to a lower position, than vice-versa), where participants are subject to laws of physics.  Is this not the same with Jedi battles?  It'd be nice to know if there is an explanation that fits within the scope of the story.


I am writing a piece where multiple seemingly disparate (even juxtaposed, without a common mission) government organizations are combining their efforts in somewhat of an unpublicized task force.  This collaboration is not necessarily classified or secret, but it doesn't become known until when they make their bombshell announcement.     In a rare ______ of inter-agency cooperation, ...   What is a good word to describe this sort of arrangement that doesn't have the negative connotation associated with collusion?      EDIT: I'm looking specifically to include the unpublicized/secret aspect.  Also, I'm not tied to a noun answer per se, other parts of speech are welcome as well.

In my resume, I'm describing several projects I've worked on in the past. Most of them were done in teamwork. What is the best way to say this?  Examples:  Together with XY, I built ... OR  In collaboration with XY, I built ... OR  XY and I built ...  Are the first two examples grammatically correct? I'm unsure since first I state that something has been done in collaboration with a second person, but then I use "I built ...".


If $G$ is a finite group in which every proper subgroup is abelian, show that $G$ is solvable.     I'm working on this proof and already proved that a subgroup in which every proper subgroup is abelian will not be simple and therefore contains a normal subgroup.    Because this group doesn't have to be of maximal order I can't use the answer here   So I was thinking it should be possible to proof that the commutator subgroup is a proper subgroup and create the required derived series. $1\trianglelefteq$ $\mid G,G\mid$ $\trianglelefteq G$ which would prove solvability.    I found another proof here  which covers concepts which were not yet part of the book I'm working through. Specifically I'm not familiar with  transitive substitution groups or primitive groups.   The question is from Exercise 56 in Chapter 4.5 in the book Abstract Algebra of Dummit and Foote.

Let $G$ be a finite group with the property that all of its proper subgroups are abelian. Let $N$ be a normal subgroup of $G$. Prove that either $N$ is contained in the center of $G$ or else $G$ has a normal abelian subgroup of prime index.  I think $G$ is solvable. . I hope that idea maybe usefull.  Help me some hints.  Thanks a lot.  P/s: This is a question comes from a qualifying exam in Algebra ( Wisconsin August $1979$ )


$$\large\lim\limits_{n\to\infty}\left(1+\sqrt{2+\sqrt[3]{3+\sqrt[4]{4+\sqrt[5]{5+\sqrt[6]{6+\cdots+\sqrt[n-1]{(n-1)+{\sqrt[n]{n}}}}}}}}\right)$$  I can only obtain the numerical approximation of it:  $$2.911639216245824$$  How to find a mostly simplified cloed form expression?

$$\lim_{n\to\infty}1+\sqrt[2]{2+\sqrt[3]{3+\sqrt[4]{4+\ldots+\sqrt[n]{n}}}}$$  I have no idea about this.  The equation can be written in its recursive form as:  $$f(n) = g(1,n)$$  Where  $$g(x,n) = [x\impliedby n]\cdot (x+ g(x+1,n))^{\frac 1x}+[x=n]\cdot (n)^{\frac 1n}$$  Of course, [] is the indicator function representing of piece wise notation.


I have 7000 files I would like to copy to a folder from home/Videos to /usr/share/someplace. How do I do this?

I am trying to copy the contents of a folder to another folder in a different directory using terminal.  Would somebody be able to provide me an example of the command line syntax required to achieve this?


#include <iostream> using namespace std;  int main() {     float f =9.58;     if(f<9.58)     {         cout<<"T";     }     else     {         cout<<"F";     }     return 0; }  As per the logic, 9.58 is equal to 9.58 so it should return false but it is returning true.

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


\documentclass[compress]{beamer} \usetheme{Dresden} \usecolortheme{crane} \title{\LaTeX~\textsc{Beamer}Testing} \author{Testname} \institute{Testing University} \setbeamertemplate{navigation symbols}{} %%--------------------------- \begin{document}  \section*{} \begin{frame} \titlepage \end{frame}  \section{SecA}\subsection{sub1}\frame{Hello01}\subsection{sub2}\frame{Hello02}\subsection{sub3}\frame{Hello03} \section{SecB}\subsection{sub1}\frame{Hello04}\subsection{sub2}\frame{Hello05}\subsection{sub3}\frame{Hello06} \section{SecC}\subsection{sub1}\frame{Hello07}\subsection{sub2}\frame{Hello08}\subsection{sub3}\frame{Hello09} \section{SecD}\subsection{sub1}\frame{Hello10}\subsection{sub2}\frame{Hello11}\subsection{sub3}\frame{Hello12} \section{SecE}\subsection{sub1}\frame{Hello13}\subsection{sub2}\frame{Hello14}\subsection{sub3}\frame{Hello15} \section{SecF}\subsection{sub1}\frame{Hello16}\subsection{sub2}\frame{Hello17}\subsection{sub3}\frame{Hello18} \section{SecG}\subsection{sub1}\frame{Hello19}\subsection{sub2}\frame{Hello20}\subsection{sub3}\frame{Hello21} \end{document}   When I render this via pdfLaTeX, everything go right. But when I choose XeLaTeX, those subsection bullets in navigation bar doesn't have a hyperlink in them. I really need to use XeLaTeX for my BEAMER, because a xeCJK package has a wonderful effect in my work, and it only works in xeLaTeX.  I want the bullet hyperlink be normal in xeLaTeX just as in pdf LaTeX.

Recently (about 5 mins ago) I found that miniframes, a Beamer outer template, does not works properly if I compile the file by XeLaTeX.  To be specific, I tried to compile this MWE  \documentclass{beamer} \usetheme{Ilmenau} \begin{document} \section{Section 1} \subsection{Subsection 1} \frame{1}\frame{2}\frame{3} \subsection{Subsection 2} \frame{4}\frame{5} \section{Section 2} \subsection{Subsection 1} \frame{6}\frame{7}\frame{8}\frame{9} \section{Section 3} \subsection{Subsection 1} \frame{10}\frame{11} \subsection{Subsection 2} \frame{12}\frame{13}\frame{14} \subsection{Subsection 3} \frame{15}\frame{16}\frame{17}\frame{18} \end{document}   with LaTeX, LuaLaTeX, and XeLaTeX separately. For the first two compilers the small circles are clickable while for the third compiler they are not. (The cursor does not become a hand while hovering). At the same time, three compilers produce clickable (sub)section titles.  I guess TeX.SX is not a good place to report bugs. But I am not sure if this is of XeLaTeX or of Beamer.  P.S. I am using OS X 10.11.1 and MacTeX and I just synced my packages.


I found this expression for the time-evolution operator: $$\begin{split} U(t) & = T_{\leftarrow}\exp\left[-i\int_0^t ds H(s)\right] \\ &= \exp\left[-\frac{1}{2}\int_0^t ds\int_0^t ds' [H(s),H(s')]\theta(s-s')\right]\exp\left[-i\int_0^t ds H(s)\right]\end{split}$$ with $H$ Hamiltonian and $\theta(s-s')$ the Heaviside step function. The commutator of the Hamiltonian at two different times is a c-number function, I don't know if it's important. Does anyone know how to get the last part?

I have a question concerning the time ordering operator. Let's suppose we have a time evolution generated by some Hamiltonian $H(t)$ given by $$ U(t)=T_\leftarrow\exp\left(-\mathrm{i}\int_0^t\mathrm{d}s\,H(s)\right)\tag{1}. $$ In Breuer and Petruccione, it's said that if the commutator of the Hamiltonian at some time $t$ with itself at some other time $t^\prime$ is a $c$-number function/ a complex function, i.e. $$\left[H(t),\,H(t^\prime)\right]=f(t,t'),$$ then the time evolution is given by $$ U(t)=\exp\left(-\frac{1}{2}\int_0^t\mathrm{d}s\int_0^t\mathrm{d}s^\prime\,\left[H(s),\,H(s^\prime)\right]\Theta(s-s^\prime)\right)$$ $$\times \exp\left(-\mathrm{i}\int_0^t\mathrm{ds}\,H(s)\right),\tag{2} $$ where $\Theta(s-s^\prime)$ is the Heaviside function. No proof or reference is given and I could not find any explanation anywhere, this is why I ask here. Any help would be very appreciated.


please could you tell what is the best common quality export value for .jpg image export in the GIMP? For example I set up the 100% for .jpg and for example for image 1,5 MB I will get the 5,2 MB or even more then 7 MB. Is it really better quality than the original photo? Is there any advantages to keep photo in this high quality?

When you export a picture to JPG you can normally choose its quality in a 1-100 scale. I like to keep a good quality but it wouldn't make sense to keep a JPG that will be almost as big as the original RAW, so is there any guideline to select a particular JPG quality for particular uses? I am mostly interested in Internet sharing and ordering prints online.


I tried to su to root so I could install lights, but I get an authentication error when I try:    user@host:~$ su Password:  su: Authentication failure

I am having problems with the su command. I know my password and I am typing it correctly but su indicates authentication failure.  So I checked on the internet and then went into recovery mode and changed my username's password to what I was entering before.  Even now entering the same password on su gives me authentication failure.  Please suggest what am I doing wrong??


This is a part from a homework. I solved all examples apart from this one. So the task is: We know that $3$ divides $a^2 + b^2$. Prove that $3$ divides $a$ and $3$ divides $b$. I cannot think of anything useful. I know that $a^2 + b^2 = (a + b)^2 - 2ab$, but I don't see how it can help me :(  Best regards, Petar

For elements $a$ and $b$ in the ring $\Bbb{Z}$ prove that if $3\mid a^2+b^2$ then $3\mid a$ and $3\mid b$.  I tried proving it but I just don't manage to. Maybe I am missing some basic claims in the number Theory?  I would appreciate hints and, generally, your help.  I am sorry, there was another data I was given, I was fixed and resent to me.


while trying to find the nature of elements in the ring $\frac{\Bbb{Z}[X]}{(2, X)}$. I just put $X=0$, and $2=0$ so the all polynomials with even constant term belongs to the ideal $( X,2)$, and I am left with the elements of the form. $1+(X,2)$, I don't know whether it's correct or not. Can anyone help?

I'm asked to prove that the quotient ring $\mathbb{Z}[x]/\langle x, 2\rangle$ is isomorphic to $\mathbb{Z}_2$.  The first thing that came to my mind was to apply the Theorem of Homomorphism of Rings, but to do so I need to construct a homomorphism $\phi: \mathbb{Z} \to \mathbb{Z}_2$, such that $\mathrm{Ker}\phi = \langle x, 2\rangle$ ($\langle x, 2\rangle$  is an ideal of $\mathbb{Z}[x]$). But     What elements are in $\mathbb{Z}[x]/\langle x, 2\rangle$ in the first   place?   I know that $\langle x, 2\rangle$ of all the polynomials with even constant term, but I can't figure out how the elements of $\mathbb{Z}[x]/\langle x, 2\rangle$ look like.  Any help would be appreciated.


Python dictionaries use hashing to get O(1) complexity for certain operations.  I know a hash is a function that converts an inmutable object into a unique identifier of a certain length of bits.  However I still dont' understand how certain operations work at a low level.  At a low level, I could understand that if the hash function would translate a key into a memory position, then getting the dictionary value for a certain key would be just hashing that key, going to that memory position and retrieving the value. But I suspect this is not how it really works, basically because the entire range of possible hashes would have to be allocated into memory.  Checking if a dictionary has a certain key is also O(1), and I really don't figure out how it's done to be O(1) using hashes. Sure I have a hash, now what? I still need to check if this hash value belongs to a list of hash values right? And this is not O(1).  Is there a tutorial or documentation where it really explains at a low level how the different operations of dictionaries involving hashes are done?   All tutorials I found explain how to use dictionaries, but I want to know how they work.  I'm not interested in the hashing algorithm itself, but what comes after the hash is calculated.  Thanks

Does anyone know how the built in dictionary type for python is implemented?  My understanding is that it is some sort of hash table, but I haven't been able to find any sort of definitive answer.


I have found only a small handful of posts from around the internet regarding Shortcodes and allowing them to work / execute within Admin Pages.  So, I have made several admin pages in Wordpress, and one of them requires me to add a shortcode from one of the other plugins.  I have found this solution which according to the comments it works:   However, the example in the answer uses [example] as the shortcode, the shortcode I am trying to use is [customcont form=3] If you notice, there is a space in my shortcode which is what puzzled me.  Because of that I'm now struggling how to incorporate that into the example that is on that thread??  This is not a duplicate question, I'm asking how to add my shortcode with a space into the example provided.  Thank you in advance!

I'm using a few plugins that have shortcodes ... however, instead of creating a public page for the content, I've created some new pages within the admin using add_menu_page and I need to know how to utilize do_shortcode() within this context.  As it stands, all the function does it spit out the string. I'm assuming it's because the shortcode API isn't available within an admin page.  How do I get around this? There is no documentation that I can find that explains how to utilize shortcodes within the WP Admin... or if it's even possible.    Specifically I'm trying to utilize WooCommerce shortcodes within the WP Admin. I hate the fact that plugins don't utilize the WP Backend for account/user management.


Is there a way with biblatex to automatically cite all papers with a certain keyword or from a certain resource, while keeping the original citation order and adding the uncited publications at the end?  The usual way, i.e. with \nocite{*}, includes all resources, which is definitely not wanted and would include other1 in the example below. Putting a \nocite{*} in a refsection, the citation markers are not related to the main text.  \begin{refsection}{lib-own.bib}   \nocite{*} \end{refsection} \printbibliography[...,section=1]     \documentclass{scrartcl} \usepackage[style=phys,biblabel=brackets,pageranges=false,backend=biber,sorting=none,defernumbers=true]{biblatex} \usepackage{filecontents}  \begin{filecontents}{lib-own.bib} @article{own1,     author = {John Doe},     title = {First pub},     year = {1993},     keywords = {mypub} }  @article{own2,      author = {John Doe},     title = {Second pub},     year = {1994},     keywords = {mypub} }  \end{filecontents} \begin{filecontents}{lib-other.bib}   @article{other1,     author = {Otto Maler},     title = {First ref},     year = {1993}   }    @article{other2,      author = {Peter Schuster},     title = {Second ref},     year = {1994}   }  \end{filecontents}  \addbibresource{lib-own.bib} \addbibresource{lib-other.bib}  \begin{document}  \cite{own1}\cite{other2}  \printbibliography[keyword={mypub},heading=subbibliography,prefixnumbers=S,title=publications] \printbibliography[notkeyword=mypub,heading=subbibliography,resetnumbers=true,title=references]  \end{document}

I would like to print a bibliography which includes all entries with a certain keyword (and possibly some additional entries).  I know that I can filter by keyword when I print the bibliography using  \printbibliography[keyword=<keyword>]   but this will only print entries which I have cited. I could, of course, use  \nocite{*}   to add all entries to the bibliography and then print just those I want.  However, this will make my .bbl file huge as my database is enormous.  Another possibility is to use Biber or another tool to prepare a document-specific .bib file containing only those entries with the keyword. However, this would need to be recreated if additional entries with the keyword are added to my main database files.  Here's an MWE to play with, annotated to indicate the way I'd like it to work ;), and the disadvantages of the way it (almost) works.  The issue of excluding explicitly cited entries is less of an issue for me. The thing I'd really like to work around is adding the entire database contents to the .bbl.  \RequirePackage{filecontents} \begin{filecontents}{\jobname.bib} @book{new-stuff,     author          =   {Watt, Brian},     title           =   {Happy Times with Penguins},     publisher       =   {Harvard University Press},     address         =   {Cambridge, MA},     year            =   1995,     pagination      =   {section},     keywords        =   {happy}} @book{den-coll,   author                =   {Till, Jr., Dennis E.},     booktitle           =   {Penguin Land and Further North: Human Influence},     title               =   {Penguin Land and Further North: Human Influence},     publisher           =   {Oxford University Press},     year                =   2008,     address             =   {Oxford and New York},     keywords            =   {penguin, human}} @book{old-stuff,   author                =   {Harvey, Jr., Dennis E.},     booktitle           =   {Penguin Land and Further North: Human Influence},     title               =   {Penguin Land and Further North: Human Influence},     publisher           =   {Someone \& Daughters},     year                =   1567,     address             =   {Oxford},     bookpagination      =   {paragraph},     keywords            =   {penguin}} \end{filecontents} \documentclass{article} \usepackage[defernumbers=true]{biblatex} \bibliography{\jobname} \begin{document}  \cite{old-stuff}  % what I would like to work % \nocite[keyword=happy] % \printbibliography  % what does work - except that \cite{old-stuff} is ignored and, more importantly, den-coll is added to the .bbl \nocite{*} \printbibliography[keyword=happy]  \end{document}


I am new to GIT, currently in my project they are using bitbucket and SourceTree. I am only using bit bucket for cloning project and source tree for taking that project on my local drive.When does GIT come into the picture  My Confusion is:    What is the particular use of source tree, bit bucket and GIT?  How GIT is related to SurceTree and bit bucket? How GIT is related to Github?

Ok, after seeing , I have decided to skip to the end and go with .  So what I need is a beginner's practical guide to Git.  "Beginner" being defined as someone who knows how to handle their compiler, understands to some level what a  is, and has touched source control without understanding it very well.  "Practical" being defined as this person doesn't want to get into great detail regarding what Git is doing in the background, and doesn't even care (or know) that it's distributed.  Your answers might hint at the possibilities, but try to aim for the beginner that wants to keep a 'main' repository on a 'server' which is backed up and secure, and treat their local repository as merely a 'client' resource.  So:  Installation/Setup    How do you set up Git?  Try to cover Linux, Windows, Mac, think 'client/server' mindset.         Working with the code          How do you handle binary files (visio docs, for instance, or compiler environments)? How do you merge files changed at the "same time"?    Tagging, branching, releases, baselines    How do you pull a particular 'release'?   How do you resolve conflicts and complete the merge? How do you merge parts of one branch into another branch?        Other   Describe and link to a good GUI, IDE plugin, etc. that makes Git a non-command line resource, but please list its limitations as well as its good.    - Cross platform, included with Git  - Cross platform history viewer, included with Git  - Mac OS X  - Mac OS X history viewer  - Cross platform, commercial, beta  - console GUI for Linux  - GUI for Windows, Linux  - package for Windows, includes friendly GUI  Any other common tasks a beginner should know?     How do I work effectively with a subversion repository set as my source control source?   Other Git beginner's references                 Delving into Git     (and )    I will go through the entries from time to time and 'tidy' them up so they have a consistent look/feel and it's easy to scan the list - feel free to follow a simple "header - brief explanation - list of instructions - gotchas and extra info" template.  I'll also link to the entries from the bullet list above so it's easy to find them later.


If $\dfrac {x} {\infty }=0,$ where $x$ is a finite number, than wouldn't $0\cdot \infty $ be equal to any number? Making this not work?

I did a bit of math at school and it seems like an easy one - what am I missing?  $$n\times m = \underbrace{n+n+\cdots +n}_{m\text{ times}}$$  $$\quad n\times 0 = \underbrace{0 + 0 + \cdots+ 0}_{n\text{ times}} = 0$$  (i.e add $0$ to $0$ as many times as you like, result is $0$)  So I thought an infinite number of $0$'s cannot be anything but $0$? But someone claims different but couldn't offer a reasonable explanation why. Google results seemed a bit iffy on the subject - hopefully this question will change that.


The Lord Of The Rings appears to be the "One Ring" not Sauron! Sauron himself can't control any ring without one ring. Sauron appears to have no power over the elven rings! If anyone who has enough power to use the One Ring he can control all the other rings and become the lord of the rings. There are many many examples that proves this. I am not sure why people think Sauron is the Lord of the Rings. It appears to me it's the ring of power itself and not Sauron that is the Lord of the Rings. So is it Sauron or the Ring itself that is Lord of the Rings?

Who is the Lord, as referred to in the title? Frodo? Sauron? Someone else? Or is it more of an abstract title, not referring to a single person, like "He who wields the One Ring"?


I am confused by this , in which the speaker claims usages like 'How to say egg in Chinese' is incorrect, and 'How do you say egg in Chinese' is correct. Is it right?

This question is inspired by comments on . The original poster wrote:     How to correct this error?   And comments say that it's an incorrect question. Better is     How do I correct this error?   I am not a native English speaker, so the fact that both versions sound natural to me is quite irrelevant. But I would like to ask anyway whether the first version is really bad.  I have seen a lot of questions starting with How to, so if you say that the first version is incorrect, could you please summarize when it is OK to use How to and when it is preferable to say How do I.


What should I do to uninstall/remove Abaqus from Ubuntu 14.04 LTS?  I did not install abaqus by commmand "sudo apt-get ....", now I don't know how to remove it from ubuntu. I followed instruction as shown in the following . Could anyone help me to solve?

How can I install applications like Google Chrome on Ubuntu?  Are there any commands to install an application?    Index of answers:


From what I have learned, objects must accelerate as they approach a heavy mass. But I also know that they cannot travel faster than the speed of light.   What if you had a proton travelling at .99999c towards a heavy object? Would it have to keep accelerating or would the acceleration of the proton slow down to zero and only it's mass would increase?   Edit: If the latter is true, then why do we describe a gravitational field by its effect on velocity? (i.e. Earth's gravitational field is always described as 9.8m/s^2). Shouldn't it be described by its effect on momentum?

Imagine we have something very heavy (i.e supermassive black hole) and some object that we can throw with 0.999999 speed of light (i.e proton). We are throwing our particle in the direction of hole. The black hole is so heavy that we can assume that in some moment acceleration of gravity would be say 0.0001 speed of light/s^2. So the question is what will be the speed of proton in few a seconds later, assuming we have such distances that it will not hit the black hole before.


ive got a a canon t5i rebel.. im an amateur photographer. Basically when i shoot for example and normal picture i use the camera viewer point as usual but sometimes as i press the shutter button half and then during that process the image gets focus but when im gonna shoot it gets blurry. I dont know if im doing it wrong or which settings should i use or put in the menu. I wanna be able to just focus and shoot sharp and clearly. Btw im using autofocus.   Thanks.

I use a Canon EOS Rebel T3i (600D) with the kit lens. I have experimented a lot with different settings and modes, but I feel like I have wasted many good shots that could have looked amazing, if only they were a little bit sharper.  I use auto-focus on most of my pictures and make sure to choose the right focus point, but all of my photos are still a little bit out of focus. When I zoom in, I can see that the pixels are not very crisp or well-aligned.  I am not sure if this issue is caused by my equipment or skills.


I just read . It was helpful, but I'm left with the question:  If you accidentally press "CTRL+ALT+F12" is the only way out of the virtual terminal to reboot the machine?  I tried every combination of (CTRL, CTRL+ALT, CTRL+SHIFT, CTRL+ALT+SHIFT, ALT, ALT+SHIFT, SHIFT) + each of the F1-12 keys to try and get back to the GUI. Nothing worked. Is the only way back into the GUI to reboot the machine?

I accidentally pressed Ctrl+Alt+F12 and my display turned to black... I then had to make a reboot.. What did it do to my system? Also what does Alt+ F8 to F10 do?