I'm trying to do this:  sudo add-apt-repository \    "deb [arch=amd64] https://download.docker.com/linux/ubuntu \    $(lsb_release -cs) \    stable"   And getting:  Traceback (most recent call last):   File "/usr/bin/add-apt-repository", line 11, in <module>     from softwareproperties.SoftwareProperties import SoftwareProperties, shortcut_handler   File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 28, in <module>     import apt_pkg ModuleNotFoundError: No module named 'apt_pkg'   OK, like , I'm removing and reinstalling python-apt and python3-apt, but then I get:  sudo add-apt-repository    "deb [arch=amd64] https://download.docker.com/linux/ubuntu \    $(lsb_release -cs) \    stable" sudo: add-apt-repository: command not found   Like , I do:  sudo apt-get install software-properties-common   But then I get the same issue as the first one: ModuleNotFoundError: No module named 'apt_pkg' and it all starts over. What should I do?


Any adjective synonymous to the following description

Is there an adjective meaning living your life as you want to etc saying, doing, behaving  and don't care what other people think about you? It can be formal or informal  I know the slang word "based" but it's very informal. urbandictionary.com/define.php?term=Based


biblatex keys inside editor are not equal to printed bib keys

I have a discrepancy between the bib keys I write inside my LaTeX editor and the printed bib keys.   See my MWE please:  \documentclass[fontsize=12pt,a4paper,oneside,  listof=totoc,                   % Tabellen- und Abbildungsverzeichnis ins Inhaltsverzeichnis bibliography=totoc,             % Literaturverzeichnis ins Inhaltsverzeichnis aufnehmen titlepage,                      % Titlepage-Umgebung statt \maketitle headsepline,                    % horizontale Linie unter Kolumnentitel %abstracton,                    % Überschrift beim Abstract einschalten, Abstract muss dazu in {abstract}-Umgebung stehen DIV12,                          % auskommentieren, um den Seitenspiegel zu vergrößern BCOR=0mm,                       % Bindekorrektur, die den Seitenspiegel um 6mm nach rechts verschiebt. geometry package überschreibt diesen Wert ]{scrreprt}  \usepackage[ngerman]{babel}     % deutsche Trennungsregeln und Übersetzung der festcodierten Überschriften \usepackage[style=authoryear, backend=biber, isbn=false, doi=false, maxcitenames=2, uniquename=false, maxbibnames=10]{biblatex} %sorting=none if not alphabetically, maxcitenames, maxbibnames  \begin{filecontents}{\jobname.bib} @misc{OReilly.2005,  author = {O'Reilly, Tim},  year = {2005},  title = {What Is Web 2.0: Design Patterns and Business Models for the Next Generation of Software} } @misc{OReilly.2005b,  author = {O'Reilly, Tim},  year = {2005},  title = {Web 2.0: Compact Definition} } \addbibresource{\jobname.bib} \end{filecontents} \begin{document}     \cite{OReilly.2005} \cite{OReilly.2005b} \printbibliography \end{document}   My first citation points to the second bib entry inside the compiled pdf and vice versa. Reading the compiled pdf is no problem in this case but it confusing the heck out of me when I write.   I guess biblatex is doing this because it is sorting the bib entriey alphabetically... I would expect this behavior:   \cite{OReilly.2005} => OReilly 2005a  \cite{OReilly.2005b} => OReilly 2005b  Is this changeable without a lot of effort or am I doing something wrong here?


I have shown a group of order 10 has a cyclic subgroup of order 5. But now I am stuck. Any hints?


Is there a way to compare network-wide rep?

On Area 51, I can see that Jon Skeet has over 1M rep, and Gilles has 828k. But I doubt those are the highest.  So is there a way to compare network-wide rep?


Ign:1 https://download.01.org/gfx/ubuntu/17.04/main zesty InRelease  Err:2 https://download.01.org/gfx/ubuntu/17.04/main zesty Release 503 Service Unavailable  Hit:3 http://us.archive.ubuntu.com/ubuntu zesty InRelease  Get:4 http://us.archive.ubuntu.com/ubuntu zesty-updates InRelease [89.2 kB]  Get:5 http://security.ubuntu.com/ubuntu zesty-security InRelease [89.2 kB]  Get:6 http://us.archive.ubuntu.com/ubuntu zesty-backports InRelease [89.2 kB]  Get:7 http://us.archive.ubuntu.com/ubuntu zesty-updates/main amd64 DEP-11 Metadata [52.7 kB]  Get:8 http://us.archive.ubuntu.com/ubuntu zesty-updates/main DEP-11 64x64 Icons [26.3 kB]  Get:9 http://us.archive.ubuntu.com/ubuntu zesty-updates/universe amd64 DEP-11 Metadata [171 kB]  Get:10 http://us.archive.ubuntu.com/ubuntu zesty-updates/universe DEP-11 64x64 Icons [223 kB]  Get:11 http://us.archive.ubuntu.com/ubuntu zesty-updates/multiverse amd64 DEP-11 Metadata [5,840 B]  Get:12 http://us.archive.ubuntu.com/ubuntu zesty-backports/universe amd64 DEP-11 Metadata [5,140 B]  Get:13 http://security.ubuntu.com/ubuntu zesty-security/main amd64 DEP-11 Metadata [12.5 kB]  Get:14 http://security.ubuntu.com/ubuntu zesty-security/main DEP-11 64x64 Icons [11.6 kB]  Get:15 http://security.ubuntu.com/ubuntu zesty-security/universe amd64 DEP-11 Metadata [20.7 kB]  Get:16 http://security.ubuntu.com/ubuntu zesty-security/universe DEP-11 64x64 Icons [36.5 kB]  Get:17 http://security.ubuntu.com/ubuntu zesty-security/multiverse amd64 DEP-11 Metadata [208 B]  Reading package lists... Done  E: The repository 'https://download.01.org/gfx/ubuntu/17.04/main zesty Release' does no longer have a Release file.  N: Updating from such a repository can't be done securely, and is therefore disabled by default.  N: See apt-secure(8) manpage for repository creation and user configuration details.


No return value in Python program for calculating square roots

I'm starting out with learning Python 3.7, and wrote this very simple practice program for finding the square root of a number. # User enters a number x = int(input("Enter a number, any number: "))  # Start with a random guess (g) of 4 g = 4  # Check if g*g = x # If not, redefine g as avg of g and x, square, then recheck  while g*g != x:     g = (g + x/g)/2  # When g*g = x, print g  else:     print(g)  For some numbers, the program works just fine. For others, however, the program simply doesn't resolve. So, for example, if I run this program (in Spyder) and enter 56, it returns a value of 7.483314773547883. If I enter 66, the console doesn't return an output. It simply idles until I interrupt or reset it. I also tried changing the while condition to: while g*g not in range(int(x - 0.1), int(x + 0.1)):  But this threw up the same problem. I'd appreciate any advice on what the issue might be here.


Is there a way to write log4j logging events to a log file that is also being written to by other applications. The other applications could be non-java applications. What are the drawbacks? Locking issues? Formatting?


In the midst of a proof I am reading the following lines are present:  For $I\subseteq [a,b]$ and $f,g: [a,b]\to \mathbb{R}$ be integrable on $[a,b]$:  $\inf\{(f+g)(x):x\in I\}\geq \inf\{f(x):x\in I\}+\inf\{g(x):x\in I\}$  and   $\sup\{(f+g)(x):x\in I\}\leq \sup\{f(x):x\in I\}+\sup\{g(x):x\in I\}$.  Why are they true? Some variation of the triangle inequality?


What are the conditions for integers $D_1$ and $D_2$ so that $\mathbb{Q}[\sqrt {D_1}] \simeq \mathbb{Q}[\sqrt {D_2}]$ as fields.  Here $\mathbb{Q}[\sqrt {D}] := \{a + b \sqrt D \mid a,b \in \mathbb{Q} \}$  Really not sure where to begin with this sort of problem. I was thinking that I should split into cases where the integer is a square or not.


Installing Debian on Ubuntu 18.04 on a MacBook

I have an old MacBook (model A1342, year 2009) with Ubuntu 18.04 on it. NO MacOSx. I want to install Debian (8 or 9) for which said computer comfortably fulfills the minimum tech specs (barely so with Ubuntu 18.04). So far I have made several bootable USBs (with sudo dd) with different packages of Debian 9 (have yet to try Debian 8), but the computer never recognizes them, much less boots from them. I'm about to make another bootable USB with UNetbootin, let's see how I fare. However, is there any advice or experience you could share on how to change Linux distro on a Mac computer?  Many thanks for your help!


value stored by a variable of type double doesn't store the exact value as returned by pow()

pow(5,2) returns 24.9999 or 25.00001 depending on a compiler but when we assign it to a double variable then it becomes 25 how?  Ex   double d=pow(5,2);   here pow() returns 24.9999 or 25.0001 so d should store these values not 25


How to manage the governor limit : Maximum number of Apex classes scheduled concurrently : 100

I launch a batch which call a lot of scheduled job. But I reach the governor limit :     Maximum number of Apex classes scheduled concurrently : 100   I'm wondering what happens when this limit is reached. The next scheduled jobs are waiting the number of scheduled jobs is lower than 100 for being executed or are they all cancelled ?  And is there to way to manage the number of scheduled jobs to avoir reaching this limit ? For example wait before schedule a new job if we are near the limit.


stacking environments within user-defined environment

I am using two packages - exercise and listings. I am trying to create an environment "codeAnswer" for answers specifically containing source code, so that i don't have to do -  \begin{Answer} \begin{lstlisting} <code answer> \end{lstlisting} \end{Answer}   But it doesn't work. Any help appreciated, as always :) Buggy code below:  \documentclass[11pt]{article} \usepackage[answerdelayed]{exercise} \usepackage{listings}  %need to fix \newenvironment{codeAnswer} {     \begin{Answer}     \begin{lstlisting} } {     \end{lstlisting}     \end{Answer} }  \begin{document}  \begin{Exercise}  What is 2 + 3?   \end{Exercise} \begin{Answer} 5    \end{Answer}  \begin{Exercise} Write a piece of code that divides 5 by 2 and stores in an integer $x$.  \end{Exercise}   %Following commented part works fine %\begin{Answer} %\begin{lstlisting} %int x = 5/2;    %\end{lstlisting}    %\end{Answer}  %FOLLOWING DOESN'T WORK \begin{codeAnswer}  int x = 5/2;     \end{codeAnswer}  \shipoutAnswer \end{document}


Want to print a menu but i started with low dimensions

I designed a menu for a pizza restaurant but it seems that the dimensions and dpi is low. These are the dimensions, could someone tell me if this is okay for printing or not.    Dimensions: 595x842  Dpi: 92


Read excel data into pandas dataframe to 20 decimal places

I am trying to read data from excel using pandas.ExcelFile() into a dataframe, and then outputting a text file using to_csv.   This output text file should be at precision of 20 decimal places and rounded to 20 decimal places.  If an input value in excel is .005, my code converts it to 0.0050000000000000001 which is incorrect because of the very last digit.  It should be 0.0050000000000000000  Here's my code:   dataFrame = pd.ExcelFile("xlFile.xlsx") pd.set_option("display.precision", 20) dataFrame.ColumnToRound = dataFrame.ColumnToRound.round(20) dataFrame.to_csv("out.txt", index=False, sep='\t', float_format='%.20f')   The INPUT excel file would look like this (just one column and one value for simplicity):  ColumnToRound  .005  I have tried using the kwarg float_precision='round_trip' when reading the excel file using pandas.ExcelFile(), but it did not make a difference.    Side note: yes, I know 20 decimal places is a lot and probably more than necessary, but it was not my decision.  It has to be 20 decimal places.


Every element of a group has order $2$. Why, intuitively, is it abelian?

What is the intuition behind the fact that if every element in a group is of order $2$, we have that the group is abelian? I can prove it, but I do not know the intuition behind it.


I read part of the series in 2005, a young man was the protagonist, he was traveling to different worlds. I think he was telepathic and the most identifying thing I can remember was he had a flying snake or asp as a pet which possibly was his protector? He was in danger for some reason. Also there was a romantic interest female. The books were very distinct from one another. The second or third book he visited a planet that was extremely bio-diverse, where he was on top of all this vegetation and he realized how many layers of vegetation he would have to get to before he got to the ground and it was vast. I never finished it and it's been driving me nuts.


Why don't more mainstream statically typed languages support function/method overloading by return type?  I can't think of any that do.  It seems no less useful or reasonable than supporting overload by parameter type.  How come it's so much less popular?


MacBook display has vertical black and white lines on startup

My MackBook, on startup, its showing the following:    They are just a bunch of vertical black and white lines, and it gets stuck there.  What could be the problem?


How are AL seasonal conditions handled for characters that don't play the full season?

I have an Adventures League character and enjoy playing, but don't have the time to actually complete a full season.  So I can only "adventure" a few times a year/season.  So if I, for example, did an adventure in the Ravenloft season, how would I get out of Barovia.  Or how would I get rid of the Death Curse.  I more generic answer is what I am looking for since upcoming season may have different conditions that are acquired.  I have skipped playing in those season because I didn't know what effect they would have on my character if I acquired a condition that wouldn't be cleared by the end of the session.  I mean if you were at a convention doing multiple seasons and you played one adventure for Tomb of Annihilation and the next Adventure in Ravenloft would your character be stuck in Barovia under the Death Curse?


I would like to know what a conformal mapping from the unit disk onto an interior ellipse is. Thank you.


Why is my download speed almost 5x times lower than bandwidth test?

On bandwidth test it says my download speed is 50mbps, but at real my download speed is 500kb/s.I found this somewhere "While download managers allow for increased download on your end, download speed is also set by the other side. As this links to a hosting website, the more people that are downloading the game at once, the more time it will take for you to download. This is why a bandwidth plan can have a high download speed included, but almost never reach it. There are some ways to circumvent this, namely trying to guess what hours people will be downloading most at, and avoid them. " ,but it's not just that site so idk what to think? My question is could there be any programs slowing my download speed or what could it be?


Do we know why the Dursleys gave Harry a proper bedroom after Philosophers Stone? From their viewpoint it would seem to have been a mistake, as his rescue in Chamber of Secrets would have been harder, if not impossible, had he still been sleeping under the stairs.


Symbol \pm is lower than the number next to it

Why does the \pm sign is ower compared to the number next to it? Is it normal behaviour? How can I raise it so to be at the same level as the number?  My distribution is Vanilla TeX and it is installed less than a week ago so it is updated.    \documentclass{article}  \usepackage[top=0.7in, bottom=1.2in, left=0.8in, right=0.8in]{geometry}  \usepackage{parskip}  \setlength{\parindent}{0cm}  \usepackage{amsmath}  \usepackage{unicode-math}  \usepackage{fontspec}  \usepackage[greek,english]{babel}  \setmainfont [     Ligatures=TeX,     Extension=.otf,     UprightFont=*,     BoldFont=*Bold,     ItalicFont=*It,     BoldItalicFont=*BoldIt,     Mapping=tex-text ]{GFSArtemisia}  \setsansfont[Mapping=tex-text]{GFSArtemisia.otf}  \setmathfont{latinmodern-math.otf}  \setmathfont[range=\varnothing]{Asana-Math.otf}  \setmathfont[range=\int]{latinmodern-math.otf}  \begin{document}  $$x= \pm 1$$  \end{document}


Why didn't Qui-Gon Jin's body "vanish" after his death?

I was wondering whether there is an explanation why Qui-Gon's body does not vanish right away after he is killed by Darth Maul!? Obi-Wan's and Yoda's bodies vanish right away, while Qui-Gon's is burned at a funeral.


The sys.system_internals_partition_columns view on Azure SQL doesn't seem to exist. Is there another view I can use to examine index modifications on a per column basis against an Azure SQL DB?


Solve equation $5x^2+3x - 4 = 0$ in $\mathbb{Z}/17\mathbb{Z}$

I tried to derive full square but haven't managed to get anything useful from it. The question is: what is (more or less) general method for solving such equations?


Turn off tabbed browsing: Chrome/Firefox - Is it possible?

Is it possible somehow to revert back to the old browsing habits, i.e. no tabs in Chrome or Firefox?  I stumbled the web but I cannot find the answer to this question.


Can we use multiple regression for a binary classification problem?

I was recently asked a question by my colleague: Can we use multiple LINEAR regression for a binary classification problem?  Will the regression model be equally good as a classification model or it is not advisable at all to use multiple regression for a classification problem.  The dependent variable(y) is 0 or 1 and the model used is multiple linear regression. Is it correct to do so?


Running a command as an administrator with Runas.exe

I've read several threads about using the runas.exe command to start an elevated process. However, when I type try to use the command runas.exe /user:BruceWayne\Administrator cmd.exe, the Command Prompt opens up asking for my password, but it won't let me enter it.  I can press Enter and the Command Prompt will close, but I can't get anywhere beyond this. Does anyone have any ideas as to why this might be happening?


I was preparing for Olympiad then I got this question and I don't understand how to solve.  $a,b,c$ are real no such that $a-7b+8c=4$and $8a+4b-c=7$ find$$a^2-b^2+c^2$$


how to install Ubuntu on Asus Transformer TF101

I am Linux layman. Just entry level and learning. I have an Asus Transformer TF 101 that would like to run Ubuntu or other suitable distro. Don't know how to do it. I need help on indicating me simple, clear, understandable tutorials or documentation on how to do this. All that I found so far is to much abstruse, or improper time consuming for me on this stage. I really want to learn by understanding and doing  not by doing without understanding. Thank you very much. Gerula


BitTorrent programs killing networking - Broadcom wireless

This started happening after I did a fresh install of 14.04 (previously I was on 13.04). When ever I launch a BitTorrent client my DNS very quickly stops responding, and then the network connection itself stops working completely (to the point of disconnecting and failing to see the network again).  It works just fine on my wired connection, but with wireless (which is a Broadcom; I followed the steps here:  to get it working) then it craps out.  Edit: I have verified that I have the correct drivers installed. My output is   09:00.0 Ethernet controller [0200]: Broadcom Corporation NetXtreme BCM5755M Gigabit Ethernet PCI Express [14e4:1673] (rev 02) 0c:00.0 Network controller [0280]: Broadcom Corporation BCM4311 802.11b/g WLAN [14e4:4311] (rev 01)   and I have linux-firmware-nonfree installed.


Combinatorics: how many non-negative integers solutions are there for $x_1+2x_2+3x_3+...+nx_n=n$?

How many non-negative integers solutions are there for $x_1+2x_2+3x_3+...+nx_n=n$? (n is a non-negative integer parameter).  I can solve it with n sums one inside the other, but it isn't so nice as a final answer.  Thanks :)


I am a noob to linux.  I tried the following commands:  sudo bootnukem  sudo apt-get autoremove  dpkg -l linux-{image,headers}-"[0-9]*" | awk '/^ii/{ print $2}' | grep -v -e uname -r | cut -f1,2 -d"-" | grep -e '[0-9]' | xargs sudo apt-get -y purge  Problem is  sudo apt-get autoremove Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run 'apt-get -f install' to correct these. The following packages have unmet dependencies:  linux-image-generic-hwe-16.04-edge : Depends: linux-image-4.15.0-43-generic but it is not installed  linux-image-virtual-hwe-16.04-edge : Depends: linux-image-4.15.0-43-generic but it is not installed  linux-modules-extra-4.15.0-43-generic : Depends: linux-image-4.15.0-43-generic but it is not installed or                                                   linux-image-unsigned-4.15.0-43-generic but it is not installed E: Unmet dependencies. Try using -f.   When tried to install it fails with no space issues.  :~/bootnukem$ sudo apt-get -f install     Reading package lists... Done     Building dependency tree            Reading state information... Done     Correcting dependencies... Done     The following additional packages will be installed:       linux-image-4.15.0-43-generic     Suggested packages:       fdutils linux-hwe-tools     The following NEW packages will be installed:       linux-image-4.15.0-43-generic     0 upgraded, 1 newly installed, 0 to remove and 181 not upgraded.     7 not fully installed or removed.     Need to get 0 B/7.898 kB of archives.     After this operation, 8.141 kB of additional disk space will be used.     Do you want to continue? [Y/n] y     (Reading database ... 511782 files and directories currently installed.)     Preparing to unpack .../linux-image-4.15.0-43-generic_4.15.0-43.46~16.04.1_amd64.deb ...     Unpacking linux-image-4.15.0-43-generic (4.15.0-43.46~16.04.1) ...     dpkg: error processing archive /var/cache/apt/archives/linux-image-4.15.0-43-generic_4.15.0-43.46~16.04.1_amd64.deb (--unpack):      cannot copy extracted data for './boot/vmlinuz-4.15.0-43-generic' to '/boot/vmlinuz-4.15.0-43-generic.dpkg-new': failed to write (No space left on device)     No apport report written because the error message indicates a disk full error                                                                                dpkg-deb: error: subprocess paste was killed by signal (Broken pipe)     /var/lib/dpkg/tmp.ci/postrm ... removing pending trigger     Errors were encountered while processing:      /var/cache/apt/archives/linux-image-4.15.0-43-generic_4.15.0-43.46~16.04.1_amd64.deb     E: Sub-process /usr/bin/dpkg returned an error code (1)   My version   uname -a Linux NB128 4.15.0-39-generic #42~16.04.1-Ubuntu SMP Wed Oct 24 17:09:54 UTC 2018 x86_64 x86_64 x86_64 GNU/Linu   Any help is greatly appreciated.


Retrieving a Subscriber mobile number and email using SQL

We're creating Contacts in Marketing Cloud using the REST API  method. This works really well — in a single request we are able to create:   an Email Subscriber (that appears in the All Subscribers list) a mobile Subscriber (in MobileConnect) Subscriber Attributes (in Attribute Sets/Populations within the Contact model)   We can then use the  to search for these  Contacts. For example, the following request:  POST https://www.exacttargetapis.com/contacts/v1/attributes/search {     "request": {         "attributes": [{                 "key": "Email Addresses.Email Address"             },             {                 "key": "MobileConnect Demographics.Mobile Number"             }]      },     "conditionSet": {         "operator": "And",         "conditionSets": [],         "conditions": [{             "attribute": {                 "key": "Contacts.Contact Key"             },             "operator": "Equals",             "value": {                 "items": ["25eb9b5f-a979-37eb-6595-ffc415d6e654"]             }         }]     } }     Returns:  {   "page": 1,   "pageSize": 50,   "count": 1,   "items": [     {       "values": [         {           "id": "75d77da9-1764-e611-97ba-8cdcd4a8b025",           "key": "MobileConnect Demographics.Mobile Number",           "name": "Mobile Number",           "value": "61402123456"         },         {           "id": "42d77da9-1764-e611-97ba-8cdcd4a8b025",           "key": "Email Addresses.Email Address",           "name": "Email Address",           "value": "someone@sample.com"         }       ]     }   ],   "links": {},   "requestServiceMessageID": "ba2e0692-b2e0-47d5-8320-3d594f7a4398",   "resultMessages": [],   "serviceMessageID": "9568bf7e-55f2-45d9-a518-e7dcf88941aa" }     This is fine, but we want to retrieve a mobile number and email address for a known Subscriber/Contact using an SQL query.   Is a MobileConnect list and the All Subscribers list accessible from an SQL query?  We could always write an SSJS Script Activity to use the Marketing Cloud REST API to retrieve the response payload and insert the values into a Data Extension, but I'd rather use an SQL query if possible.


You have probably noticed that messages will pop up whenever the Sole Survivor does something to increase the companions affinity. For example if you pick a lock the message will read "Piper liked that" if she is your companion.    However, I noticed that this message does not appear all the time, there rather seems to be some kind of cooldown time intervall between messages. That is, whenever I pick two locks in short succession there will be no second message after the first.    Does that mean that affinity is unaffected by the second action? Is there some sort of cooldown phase? Or is it just the message?


Difference between administrative and user mode of MiKTeX

For a lot of questions here on TeX.SE and on other fora regarding MiKTeX, it turns out that the underlying problem actually lies in the not understood distinction between administrative and user modes. So let me ask these questions:  What’s the difference between administrative and user mode in MiKTeX, and in which situation should I use either one of these modes?


I often think about problems that require an understanding of the very essence of computation and its inherent limitations. So, my questions are as followed:   Is the universe isomorphic to a universal turing machine? Is the universe isomorphic to a universal quantum computer? What evidence do we have within our universe to support an answer to such a question? What corollaries follow from a universe that is or is not isomorphic to a universal turing machine (or universal quantum turing machine)? Is this question really answerable, and what is the current literature on this subject?   I'm mostly interested in the implications and corollaries that follow from a universe that is or is not isomorphic to a turing machine (or universal quantum computer) and the insights that it would provide us with, about the nature of computation.


Is there any kind of travel sim card for Europe?

I'm interested especially in having mobile internet in as many countries as possible of the European Union without having to rely on having wifi available


Implementing subscript text within regular text (math equation)

How do you add subscript text within a text string e.g. I would like my the output to have the max as subscript  \text{AC generator emf_max}


I have been looking the number of methods to measure inductance of a coil if you don't have an LCR meter available, and I have had some difficulty. I designed and built a coil and I would like to confirm its inductance, which theoretically is ~\$2\mu\mathrm{H}\$.  One method is putting a resistor in series with the inductor and applying a signal. I've seen two things in regards to this one is to adjust the input frequency so that the voltage across the resistor is half the input and then work out \$L\$ using         – Schematic created using  $$ L = \frac{R}{2\pi f\sqrt{3}} $$ And the other is to instead adjust the input frequency until the signals are \$-45^\circ\$ (degrees) out of phase and then work out \$L\$ using $$ L = \frac{R}{2\pi f} $$ I've tried both these on a inductor of known value and I do not get close to the expected value. So I figure I am doing something wrong, but I am not sure what as it is a pretty simple setup. More importantly, I do not fully understand the formulas used and how one gets to these to work out the inductance.  The known inductor is \$\sim 1.5 \mu\mathrm{H}\$ (tolerance 20%) and the resistor I used was \$6.75 \mathrm{k}\Omega\$. So I also wonder if perhaps the inductor value is too low for this type of setup for measurement as I have typically seen \$\mathrm{mH}\$ in the results of the examples I have seen? Or if I choose an inappropriately valued resistor?  I then tried the LC trap, with \$10 \mathrm{nF}\$ capacitor and my inductor, and that worked for me. Pulsing the input signal and then looking at ripple frequency.  $$ f = {1\over 2\pi\sqrt{LC}} $$ At least it appears to have as I was able to work out the inductance of the known inductor to within its tolerance. And got near to what I expected with my built coil.          Mostly I am curious about the first methods using the series resistor, as this is one of the first things that comes up when looking at how to measure inductance, And I would like to understand this better and get it to work for me if possible.


Why does energy need to be quantized to explain black body radiation? Wouldn't the approximate normal distribution of the kinetic energy of particles at a certain temperature be sufficient, ie. few particles have high enough energy to oscillate at higher frequencies.


Award part of reputation back to bounty owner

the question I'm talking about. I'm the OP, the bounty owner, the only one who answered and there aren't any real comments too. Wouldn't be safe to allow awarding part of bounty reputation back to myself (the bounty owner) in such cases?   I did all the hard work after all and reported back my findings to the community.  I think there's no risk I set another bounty on that question after recovering part of my reputation, thus artificially drawing more attention to the question, because there already is an accepted answer and because I still loose some rep each bounty I set. However maybe that, just now, opening a new bounty on that question would be technically possible for me anyways, but, even then, I think it's easy to make the system avoid that possibility: when the OP is allowed to award himself part of the bounty  rep (only in selected cases like mine above), and he does so, his question is automatically closed.   This feature would encourage OPs who set a bounty to find the answer themselves (which I suppose they already are, admittedly, since they set a bounty), and to report it back to the community when the question hasn't received any other answers. We shouldn't understimate that last bit of knowledge sharing: there are so many unanswered questions here I harldy believe the OP really didn't find a solution for any of them. I'm more inclined to think the OP did solve its problem somehow, but he didn't bother to share the knowledge.   Maybe the system could make this feature available to the OP only after the bounty expired, and only if the question hasn't received any other answers except the OP's one, so that we are sure none else would have replied anyway.  The conditions this feature would be available could be:   The OP is the bounty owner The question has only one answer The OP is the answer author too The answer has no downvotes The bounty has already expired   In this case I think letting the OP recover 50% of the bounty points would make sense.  It's like booking a flight after all: if you cancel the reservation you get something back, because for the company is better to return you a part of your money and KNOW they can sell that seat to someone else, rather than keeping all of your money and leaving the seat empty, just because you didn't bother to let them know, since you had nothing to loose.


I want to do the following - Save the current state of my linux OS(centOS6.5). Do some changes (more specifically inject a fault and test some service to check how it behaves when that particular type of a fault occurs.) Then restore the system back to the saved state. I am not able to figure out how to do this on a linux system. I have a machine with centOS 6.5 with an ext4 filesystem.Also this is a physical server and not a virtual machine.  Any ideas or suggestions?


Bootcamp requires Windows 7. Possible to clean install Windows 10?

I have iMac, late 2011, Intel CPU.  Original OS X was Leopard updated to High Sierra.  Hardware cannot update to any later version.  Installed Windows 7 using Bootcamp in High Sierra.  Updated Windows 7 to Windows 10. Windows 10 had problems, i.e. System Restore did not work, a driver for Bluetooth not installed.  I decided to try a clean install of Windows 10. But Bootcamp setup file prepared under High Sierra says it requires Windows 7. Because of problems when update Windows 7 to 10, is it possible to install Windows 10 without starting with Mac OS X / Windows 7?  Note: Windows 10 will do a clean install (everything on drive deleted, reformat as 1 NTSF partition during Windows install). Bootcamp setup will open in Windows 10 but stops and states it requires Windows 7. Is there another version of Bootcamp available?  Note: Without Bootcamp, after installation, Windows 10 gets stuck when restarted. I get Mac white screen, then Windows blue flag with spinning dots. Screen blacks out, then starts over with Mac white screen. Repeats indefinitely. (However, no problem restarting during install process.) Thanks for any information.  Bad news accepted, just want to know if this is possible and how to do it. If not; I'll deal with it.  Many thanks in advance.


Prove that $ \int _a^b\:f\left(x\right)\:\:dx\:=\:\int _a^b\:f\left(a+b-x\right)\:\:dx $

This is the prove- $y=a+b-x$. Then $dy/dx=-1$ and thus $$\int_a^bf(a+b-x)dx= \int_b^a-f(y)dy = \int_a^bf(x)dx$$  But I dont understand the last part of this - Why ? $$\int_b^a-f(y)dy = \int_a^bf(x)dx$$  I know that $\int_b^a-f(y)dy = \int_a^bf(y)dy $. But something is not clear to me.


New Feature: real time updates to questions, answers, and inbox

We have deployed a new feature that hopefully help with keeping you instantly updated as new questions and answers are posted.  All sites except for Stack Overflow have a new activity indicator on the homepage which will show when new posts are asked or answered.    We have also enabled updates on the questions page for the newest and active tabs for all sites except Stack Overflow.  If you open a browser to these tabs you will receive instant notifications when new questions are asked or answered.    Stack Overflow has a massive amount of activity so we have decided to limit this feature to tags only.  Both the "newest" and "active" tab will have updates after first selecting a tag or tag combination.    We recently added support for new answers and comments:        Now for the gotchas - in order to use this feature you must have a browser that supports web sockets.  See:   for a list of browsers that currently support web sockets.  UPDATE  As a few have mentioned below we are now experimenting with updating comment counts, votes on a post, and your reputation score.


What can cause my shell to look like this?

I'm currently developing a home automation framework for my apartment. This involves getting JSON over Serial from an Arduino. When the JSON can't be parsed (usually only on startup) I log it as an error.  Today something strange happened though, the broken JSON caused one of my terminals to become weird.  [nodemon] restarting due to changes... [nodemon] starting `node build/server` sensor living-room-humidity on serial:arduino-master:42 sensor living-room-temperature on serial:arduino-master:42 sensor living-room-motion on serial:arduino-master:42 sensor living-room-brightness on serial:arduino-master:42 sensor kitchen-humidity on serial:arduino-master:43 sensor kitchen-temperature on serial:arduino-master:43 sensor kitchen-motion on serial:arduino-master:43 sensor kitchen-brightness on serial:arduino-master:43 listening on http://127.0.0.1:50000 serial opened: arduino-master serial error can't parse JSON:  S≤┼├▒│E⎼⎼⎺⎼: U┼e│⎻ec├ed ├⎺┐e┼ ⎽e⎼☃▒┌ d☃⎽c⎺┴e⎼ed: /de┴/├├≤USB▮ /#Y⎼dB▒±dPSX2≤TB☃8AAAA c⎺┼┼ec├ed /#Y⎼dB▒±dPSX2≤TB☃8AAAA ▒┤├▒e┼├☃c▒├ed [┼⎺de└⎺┼] ⎼e⎽├▒⎼├☃┼± d┤e ├⎺ c▒▒┼±e⎽↓↓↓ [┼⎺de└⎺┼] ⎽├▒⎼├☃┼± ◆┼⎺de b┤☃┌d/⎽e⎼┴e⎼◆ ⎽e┼⎽⎺⎼ ┌☃┴☃┼±↑⎼⎺⎺└↑▒┤└☃d☃├≤ ⎺┼ ⎽e⎼☃▒┌:▒⎼d┤☃┼⎺↑└▒⎽├e⎼:42 ⎽e┼⎽⎺⎼ ┌☃┴☃┼±↑⎼⎺⎺└↑├e└⎻e⎼▒├┤⎼e ⎺┼ ⎽e⎼☃▒┌:▒⎼d┤☃┼⎺↑└▒⎽├e⎼:42 ⎽e┼⎽⎺⎼ ┌☃┴☃┼±↑⎼⎺⎺└↑└⎺├☃⎺┼ ⎺┼ ⎽e⎼☃▒┌:▒⎼d┤☃┼⎺↑└▒⎽├e⎼:42 ⎽e┼⎽⎺⎼ ┌☃┴☃┼±↑⎼⎺⎺└↑b⎼☃±▒├┼e⎽⎽ ⎺┼ ⎽e⎼☃▒┌:▒⎼d┤☃┼⎺↑└▒⎽├e⎼:42 ⎽e┼⎽⎺⎼ ┐☃├c▒e┼↑▒┤└☃d☃├≤ ⎺┼ ⎽e⎼☃▒┌:▒⎼d┤☃┼⎺↑└▒⎽├e⎼:43 ⎽e┼⎽⎺⎼ ┐☃├c▒e┼↑├e└⎻e⎼▒├┤⎼e ⎺┼ ⎽e⎼☃▒┌:▒⎼d┤☃┼⎺↑└▒⎽├e⎼:43 ⎽e┼⎽⎺⎼ ┐☃├c▒e┼↑└⎺├☃⎺┼ ⎺┼ ⎽e⎼☃▒┌:▒⎼d┤☃┼⎺↑└▒⎽├e⎼:43 ⎽e┼⎽⎺⎼ ┐☃├c▒e┼↑b⎼☃±▒├┼e⎽⎽ ⎺┼ ⎽e⎼☃▒┌:▒⎼d┤☃┼⎺↑└▒⎽├e⎼:43 ┌☃⎽├e┼☃┼± ⎺┼ ▒├├⎻://127↓▮↓▮↓1:5▮▮▮▮ ⎽e⎼☃▒┌ ⎺⎻e┼ed: ▒⎼d┤☃┼⎺↑└▒⎽├e⎼ ⎽e⎼☃▒┌ d☃⎽c⎺┴e⎼ed: /de┴/├├≤USB▮ ⎽e⎼☃▒┌ e⎼⎼⎺⎼ c▒┼'├ ⎻▒⎼⎽e JSON: π"☃d":42←"b⎼☃±▒├┼e⎽⎽":126←"└⎺├☃⎺π"☃d":42←"b⎼☃±▒├┼e⎽⎽":125←"└⎺├☃⎺┼":▮←"├e└⎻e⎼▒├┤⎼e":23↓8▮←"▒┤└☃d☃├≤":29 S≤┼├▒│E⎼⎼⎺⎼: U┼e│⎻ec├ed ├⎺┐e┼ ☃ /#5┌9⎻PA°2P└_└┐c_WAAAA c⎺┼┼ec├ed /#5┌9⎻PA°2P└_└┐c_WAAAA ▒┤├▒e┼├☃c▒├ed /#5┌9⎻PA°2P└_└┐c_WAAAA d☃⎽c⎺┼┼ec├ed /#▒▒73J1G⎺CK↑▒XdVbAAAB c⎺┼┼ec├ed /#▒▒73J1G⎺CK↑▒XdVbAAAB ▒┤├▒e┼├☃c▒├ed /#▒▒73J1G⎺CK↑▒XdVbAAAB d☃⎽c⎺┼┼ec├ed /#├┌7⎺°_▒R6FDON─┐HAAAC c⎺┼┼ec├ed /#├┌7⎺°_▒R6FDON─┐HAAAC ▒┤├▒e┼├☃c▒├ed /#├┌7⎺°_▒R6FDON─┐HAAAC d☃⎽c⎺┼┼ec├ed /#┤_Q┬├XdLW1└C▒Z⎻8AAAD c⎺┼┼ec├ed /#┤_Q┬├XdLW1└C▒Z⎻8AAAD ▒┤├▒e┼├☃c▒├ed /#┤_Q┬├XdLW1└C▒Z⎻8AAAD d☃⎽c⎺┼┼ec├ed /#3☃┐R±°_⎼E⎻☃Q┼K┘▒AAAE c⎺┼┼ec├ed /#3☃┐R±°_⎼E⎻☃Q┼K┘▒AAAE ▒┤├▒e┼├☃c▒├ed     I know that this most likely can be fixed by just restarting that shell, but I still want to understand why this happens and (if possible) prevent it from happening again.


I am travelling to the UK but my UK passport is about to expire and so would like ot enter the UK with my US passport.  How is allowed and legal?


Is there a realtime train position and timetabling tool for Deutsche Bahn trains?

In the UK, there are several third-party services which consume data produced by Network Rail regarding the operational rail timetable and live train movements. These services produce data which are highly informative regarding my journey. For example, I often use such services to determine where a train originates, from which inbound service it was formed (if applicable), and to ascertain the timeliness of the service when en route. I am a particular fan of .  Are there any equivalent services for Deutsche Bahn trains? I'm aware of the , but am looking for a service which provides textual timetable information regarding train formation and intermediate passing points, rather than a graphical readout.  My current motivation is to search for the train I am shortly due to board in Brussels; the online timetable indicates it is delayed, and I wish to determine whether the train originates here and, if so, from which inbound service it forms, so I can determine whether it is likely to be in the platform already.  It would be particularly great if there was a service worked across borders into other Western European countries where DB long-distance services operate, but I can understand this is perhaps unlikely due to the cross-border data sharing required between the various network operators.


Whenever I try to connect to a server (only in the modpack SkyFactory 3, usually Minecraft connects ok) the game gives me this error: "Failed to login: Invalid Session (Try restarting your game)".


Why doesn't ignorecase flag (re.I) work in re.sub()

From pydoc:     re.sub = sub(pattern, repl, string, count=0, flags=0)       Return the string obtained by replacing the leftmost       non-overlapping occurrences of the pattern in string by the       replacement repl.  repl can be either a string or a callable;       if a string, backslash escapes in it are processed.  If it is       a callable, it's passed the match object and must return       a replacement string to be used.   example code:  import re print re.sub('class', 'function', 'Class object', re.I)   No replacement is made unless I change pattern to 'Class'.    Documentation doesn't mention anything about this limitation, so I assume I may be doing something wrong.    What's the case here?


Does decimate an object helps cycles rendering faster in blender?  If we decimate the object and use smooth shading, will it render faster specially in those scenes where lightning matters the most?


is there a way to view the source of a module from within the python console?

if I'm in the python console and I want to see how a particular module works, is there an easy way to dump the source?


Can't ask for or couldn’t ask for what to use in this following context? Is this phrase Couldn't ask for has any particular grammar rule?

I could not/ can not ask for more when i've been with my best buddy for such a long time.


In a list of ICs, along with the familiar package names such as QFN32, LQFP48, etc., I've seen a few ICs to be listed as DIE for the package size. I've never seen that description before as an IC package size, and  does not list it either.  What can it be?  I assume it's some kind of chip-scale package, but it does not reveal the silicon size or any other properties, like number of pins, etc.


Why object looks pink color in texture paint when i reopen file?

I had complete the paint on the object in Texture paint mode, after some time I had reopen that file, an object converted to pink color,why its happening like that.give me suggestion...


convert java project into windows service

I am creating an application, where it will be used by other users.  I need to run that in system of users so that it runs as a windows service. How this can be achieved? In this case user will download the application(probably as .exe or any other format) and it will start automatically as a windows service.  Thanks in advance for any response,


Can only log into chat by logging into Meta

Somehow I got logged out of Chat and SE in general recently. I logged back into Super User successfully using Chrome, but when I went to Root Access I was told that I need to log in to chat:    So I hit login, used my StackExchange ID, and got punted to... StackOverflow to 'add a login'?    Well, that was weird but at least I'm logged in to chat now, right? Or not:    I tried again but the process repeated itself. I also tried logging in via  but that also punted me back to SO without logging me in. Same effect after deleting all related cookies and incognito mode*.   A bit of searching dug up , which seemed promising. So I went to post a query on Meta about this - I had to log in to Meta as well - and started writing.  Loading up chat now shows me as logged in! I tried this again and was able to replicate.  What gives? I recently joined an SO Team, perhaps this has something to do with it?  tl;dr sequence   logged out log in to chat using StackExchange ID redirected to SO 'add a login' still not logged in to chat log in to Meta chat now logged in   Why does logging in to Chat (or StackExchange) redirect me to StackOverflow 'add a login'? And why can I log in to chat via Meta?     *: I wanted to test via Firefox but ran into a different issue there ("3rd party cookies seem to be disabled" → log in manually → StackExchange OpenID "Not found") which I can create another question for.


When I call this method sometimes it's shows exception   public static long getTimestampFromDate(String date, String format) {     DateFormat formatter = new SimpleDateFormat(format, Locale.ENGLISH);     //formatter.setTimeZone(TimeZone.getTimeZone("UTC"));     Date d = null;     try {         d = formatter.parse(date);     } catch (Exception e) {         e.printStackTrace();         Crashlytics.logException(e);     }     Calendar calendar = Calendar.getInstance();     calendar.setTime(d);     calendar.set(Calendar.HOUR_OF_DAY, 0);     calendar.set(Calendar.MINUTE, 0);     calendar.set(Calendar.SECOND, 0);     calendar.set(Calendar.MILLISECOND, 1);     return calendar.getTimeInMillis(); }      My error :   Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'long java.util.Date.getTime()' on a null object reference        at java.util.Calendar.setTime(Calendar.java:1197)        at com.utils.Utils.getTimestampFromDate(SourceFile:105)        at com.fragment.MyProfileFragment.onViewClicked(SourceFile:768)        at com.fragment.MyProfileFragment_ViewBinding$4.doClick(SourceFile:79)        at butterknife.internal.DebouncingOnClickListener.onClick(SourceFile:22)        at android.view.View.performClick(View.java:5205)        at android.view.View$PerformClick.run(View.java:21162)        at android.os.Handler.handleCallback(Handler.java:739)        at android.os.Handler.dispatchMessage(Handler.java:95)        at android.os.Looper.loop(Looper.java:148)        at android.app.ActivityThread.main(ActivityThread.java:5453)        at java.lang.reflect.Method.invoke(Method.java)        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:781)        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:671)      Date format :    public static String SLASH_MM_DD_YYYY = "dd-MMM-yyyy";      Any solutions for this?


Blender only showing a small sliver of objects in 3D View


I'm asked to prove the convergence of the sequence $$X_n=\left(1+\frac12\right)\left(1+\frac14\right)\left(1+\frac18\right)\cdots\left(1+\frac{1}{2^n}\right)$$   I proved that it is increasing through the ratio test and then I want to prove that it is bounded.  My question is the following : is it enough to say that $X_n<\left(\frac32\right)^n$ for $n>1$ or not ? Namely, can we say that a sequence is bounded if $\forall$  $n$ ,  $\exists$ a $N$ such that $X_n<N$ or do I have to find a N such that $\forall$  $n$ , $X_n<N$?  In other words, can a bound depend on $n$ ?  Thanks for your help.


virtualbox - Why can't I create a 64-bit virtual machine inside another virtual machine?

I am trying to create a new 64-bit Windows 7 virtual machine inside a 64-bit Debian 7.3.0 instance running in VirtualBox. I am allowed to run 32-bit machines, but I can not create 64-bit machines, as shown in the picture. Why is this? I have hardware virtualization enabled on the host.


Written with .          Defining for $A,B \subseteq \Bbb R$, $A+B = \{ a+b : a \in A,b \in B \}$. If A and B are two bounded closed subsets, must A+B be closed?     The question arose from the previous case where A and B were not given to be bounded and the answer came false with the example of $A = \{ 1,2,...\}\  and \ B = \{ 1-1,1-(1/2),1 - (1/3),... \}$      However, how do we prove/counter in this case?    EDIT : -  I had written 'bounded' instead of 'closed'    EDIT 2 : - I saw that there are proofs available using properties of arbitrary metric spaces but since I haven't studied them, they are beyond me. I would like to know if a proof is possible using the properties of $\Bbb R$


Why is $K:=\{x+\sqrt{2}y : x,y\in \mathbb{Q}\}$ a field?   I know that if $K$ is a sub-field of a field (in this case it should be $\mathbb{R}$?), it is a field itself.  Firstly, have to prove that if $a,b\in K \Longrightarrow a+b\in K$ $\land$ $a\cdot b \in K$  I am having trouble figuring out what $a$ and $b$ are since $x+\sqrt{2}y$ is an addition... any suggestions?


Test to see when table is candidate for compression (row or page)

Does anyone know a tool like this page  where one can determine if a table is a good candidate for row or page compression. Also I am trying to understand the benefits of compression. I have been reading about it, but still have these questions.  Will compression make more 8KB fit in the buffer cache? When does data become uncompressed i.e. in a select? will backups become faster? Is the reason that compression ads cpu overhead because e.g. inserts need to be compressed before the insert? Is there any good reason to compress tables without investigating how the tables is being used (i.e. static vs. volatile).  A colleague has started to compress many tables (page). I don't know the analysis behind this decision. I know we sometimes have resource semaphore waits during some peak hours. I actually don't think he knows what he is doing. I can see that our sos scheduler yield waits have gone slightly up. I think the compression is causing more harm and it seems that maintenance tasks overshoot more now (e.g. backups, checkdb...).


How to remove ubuntu on ubuntu and reinstall ubuntu

I couldn t find a solution since maybe 5 hours. I have checked everything on Internet. Here is my problem,   I dual booted Ubuntu 14.02 beside windows 7. I removed windows 's files accidentally. I went on with ubuntu. Today It said there isn t enough disk space. So I tried everything to fix it.   Finally I want to delete everything and reinstall ubuntu. But nothing seems to work. Please help.   I have a bootable usb with iso file of ubuntu 14.02. Everytime I restart I just see 5 options, none of them is working.


Does the 2018-2019 US government shutdown affect travelling to and from the US?

My grandparents bought a flight on United Airlines that departs on Feb 10 2019, as the one and same ticket, from Toronto, to ORD with 1 55-minute layover, then Maui. Please ping me if I ought post their return flight on Feb 24's details.   advises:     There should be no customs and immigrations formalities at ORD, as YYZ is a , and CBP matters will be handled in Toronto.    I'm assuming that  persists during their vacation to Maui.   reported some TSA agents' refusal to work.  Will  refuse to work, or any other federal workers pertinent to travelling to and from the US?


Using the definition of the binomial distribution, I obtain that: $$\Psi (t) = (pe^t+q)^n $$ I then compute $\Psi ' = npe^t(pe^t+q)^{n-1}$  I then evaluated this at $\Psi'(0)$ and got $\Psi'(0)=np(p+q)^{n-1}$  and so $E[X]$ which I know is $np$.   How do I then differentiate $\Psi'(t)$ again, the $n-1$ is throwing me off?


I am a horrendous speller, and my mild dyslexia does not help.   Sometimes I typo in my comments, I look at it a few days later and see something that screams to be fixed. But to fix it I would have to get rid of all my up votes and lose continuity.   Should we be allowed to fix minor typos in comments?


Install Ubuntu and Windows on the same pc

Some time ago I installed windows and ubuntu on the same pc. There was a problem and in grub boot loader, windows didn't appear, and I needed to reinstall all.  Now I want to install windows and ubuntu on other pc, but i can't remember... do I need to install windows or ubuntu firstly?  Thank you!


Monotonicity of the sequence $(a_n)$, where $a_n=\left ( 1+\frac{1}{n} \right )^n$

Define $a_n=\left ( 1+\frac{1}{n} \right )^n$ for $n\geq 1$. I want to show that it is increasing. First, we have $$\frac{a_{n+1}}{a_n}=\left ( \frac{1+\frac{1}{n+1}}{1+\frac{1}{n}} \right )^n\left ( 1+\frac{1}{n+1} \right )=\left ( 1-\frac{1}{(n+1)^2} \right )^n\left ( \frac{n+2}{n+1} \right )$$ Using the Bernoulli inequality, we see that, for all $n\geq 1$, $$\left ( 1-\frac{1}{(n+1)^2} \right )^n\geq 1-\frac{n}{(n+1)^2}=\frac{n^2+n+1}{n^2+2n+1}.$$ How do you then show that  $$\left ( 1-\frac{n}{(n+1)^2} \right )\left ( \frac{n+2}{n+1} \right )>1?$$  Edit: This is not a duplicate question; the question is not to show about the existence of the definition of Euler number $e$. The question is about showing that it is increasing, the way I have shown that I have been stuck with, not other ways. It seems that the question is too easy that I have been too tired to think at this late.


as we all known,CopyOnWriteArrayList can resolve the problem when the List visited by multiThread , in Java ,when we want to change the value in the list ,it makes a copy in memory. but in android ,when we call this method such as get() , it may throw ConcurrentModificationException,it is because when we call the subList() of the CopyOnWriteArrayList in android ,it make an object called CowSubList, and it has a method called Slice.checkConcurrentModification() and it throws an ConcurrentModificationException.how can I solve the problem ,when a thread is adding an item to the list and another one is visiting the list?


How to prove Fibonacci sequence with matrices?

How do you prove that: $$ \begin{pmatrix} 1 & 1\\ 1 & 0 \end{pmatrix}^n =  \begin{pmatrix} F_{n+1} & F_n\\ F_{n} & F_{n-1} \end{pmatrix}$$


Split large PDF into smaller Two-page PDFs

I have several very large PDF files that I need to split into smaller ones by page number.   For example: In a 100 page long PDF, I want to have one PDF with pages 1-2, one with 3-4, one with 4-5 and so on.. Is this possible to Automate in any way? I need to do this with several documents.


I have a computer with two sticks of DDR4 RAM, and someone just gave me some old RAM that's DDR3. Can I use both in the same computer?


Let $M$ and $N$ be $R$-modules ($R$ a commutative ring with identity). Let $m \in M$ and $n \in N$. Is there any necessary and sufficient condition to have $m\otimes n = 0$ (as an equation in $M\otimes_RN)$.


How do we pronounce month's? I mean apostrophe s after th?

How do we pronounce apostrophe s after th? For example month's? And how do we pronounce deaths?


I installed ubuntu and erased windows data and didn't made partitions while installing ubuntu. I had 2 partitions in windows 7 and now i have just one 245gb partition. I need one partition which i can use seperatly.  How do i create partitions now?


I was trying to install rvm using \curl -L https://get.rvm.io |    bash -s stable --ruby --autolibs=enable --auto-dotfiles. It worked fine until I got a configure error:  Error running './configure --prefix=/home/nishant/.rvm/rubies/ruby-2.0.0-p247 --disable-install-doc --enable-shared', please read /home/nishant/.rvm/log/1379591052_ruby-2.0.0-p247/configure.log There has been an error while running configure. Halting the installation.   Following are the contents of the mentioned log file:  [2013-09-19 17:15:58] ./configure current path: /home/nishant/.rvm/src/ruby-2.0.0-p247 command(4): ./configure --prefix=/home/nishant/.rvm/rubies/ruby-2.0.0-p247 --disable-install-doc --enable-shared checking build system type... i686-pc-linux-gnu checking host system type... i686-pc-linux-gnu checking target system type... i686-pc-linux-gnu checking for gcc... gcc checking whether the C compiler works... no configure: error: in `/home/nishant/.rvm/src/ruby-2.0.0-p247': configure: error: C compiler cannot create executables See `config.log' for more details   I then tried a "hello world" C program and got the following error on compilation:  nishant@nishant-Inspiron-1545:~$ gcc -g -o hello hello.c  /usr/local/bin/ld: this linker was not configured to use sysroots collect2: error: ld returned 1 exit status   I'm not sure why this error is thrown. I couldn't find a satisfactory answer to this on the forum. Could someone please help. Thanks


Revenge of the Sith - What they are taking revenge for?

Star Wars Episode III was titled as Revenge of the Sith. This title confuses me. We see Sidious and Vader getting rid of all Jedi which may be a part of revenge. However, what they are taking revenge for?


Isomorphism of an endomorphism ring, how can $R\cong R^2$?

I'm aware that over a commutative ring, two free finitely generated modules of finite rank are isomorphic if and only if they have the same rank.   I'm trying to understand a curious example of why this does not hold over a noncommutative ring.      Let's take $M=\oplus_{i\in\omega}\mathbb{Z}$. Then let $R=\text{End}(M)$, which is not commutative. Then $R\cong R^2$ as left $R$-modules.   It seems like one could possibly make a basis of $R$ using only endomorphisms which act on the even or odd coordinates of elements of $M$, which might suggest such an isomorphism. Is there a clear proof of why $R\cong R^2$?


Creating point features with exact coordinates in QGIS

How do I create point features with exact (manually entered) coordinates in QGIS? I get precise GPS coordinates from a survey team which I need to add to a point layer. What I want: add point, type in the coordinates and when pressing enter the point is created where it is supposed to be.


Germany Schengen visa with AirBnB booking

We (Russian citizens) are planning to go to Munich in late June. We would like to book our accommodation on AirBnB, but it is not very clear whether it will be accepted by the German embassy when we apply for a Schengen visa.  I can't find such information on the German embassy site or on the VFS-Global site. I've also searched for it on the Internet, and, while most sites agree that AirBnB booking is generally OK for a visa, I don't see a clear answer for Germany specifically, and there seems to be some exceptions for other European countries.


What exactly is the physiology of hosts in the Westworld TV series?

We learn from Ed Harris that initially, the hosts were androids - mechanical robots made to look like humans. This is also seen in some flashback sequences, and Robert, the kid who opens his face to reveal the circuitry inside. In episode 6, we learn that the hosts were later switched to the current 3D-printing process, in order to appear even more human.  However, what exactly is their physiology? Their energy source? Do they need food or store it inside a stomach chamber? Or are they charged overnight, since obviously they do need a source of electrical power for remote control and data transmission?


What are the most common mistakes that beginners of (La)TeX and Friends make?

I want to collect the most common mistakes, misconceptions, pitfalls, etc that (La)TeX and Friends users make. Please one answer for each mistake, misconception, pitfall, etc.  I am only interested in more technical, objective cases rather than psychological, social, subjective cases.  From this complete infinite list of technical and objective cases, we can have a reference how  to teach newbies much better directly or indirectly via writing a good book.  The technical and object cases are, for example, as follows.   Beginners sometimes use $\huge E=mc^2$ with the hope they will get a huge formula. It actually does not produce the expected result. The correct way is \huge $E=mc^2$. Beginner sometimes use longtable inside table because they assume longtable is the longer version of tabular which is able to be sandwiched in table. etc.


Restart Gnome process for keyboard config only?

I'm using a laptop with a detachable screen, anytime it detaches my custom keyboard settings stop working (inverted scrolling, caps remapped as hyper, etc). I can get them back by rebooting my system or running gnome-replace --shell, but both of these are inconvenient as they take time to log back in and cause me to lose all of my open applications. Does anyone know how I can restart the daemon responsible for keyboard configuration specifically? A command I can run to quickly fix the problem without relogging?


VIMRC, SCREENRC, BASHRC, KSHRC, etc. What does the "RC" mean?

In these and other applications what does the "RC" stand for?


auto populate name in people picker field

I have people picker field "Manager" and want it to auto populate in new form with constant value "kumar, brishal" How I can do it using jquery.  I am using below code, when I double click in textbox it show "kumar, brishal" but user will not like this UI. please help  <script  type="text/javascript" src="//code.jquery.com/jquery-1.11.1.min.js"></script> <link  type="text/css" rel="stylesheet" href="//code.jquery.com/ui/1.11.0/themes/ui-  lightness/jquery-ui.css" />  <script  type="text/javascript"   src="https://cdnjs.cloudflare.com/ajax/libs/jquery.SPServices/2014.02/jquery.SPServices-  2014.02.js"></script> <script  type="text/javascript"   src="https://cdnjs.cloudflare.com/ajax/libs/jquery.SPServices/2014.02/jquery.SPServices-  2014.02.min.js"></script> <script   src="https://cdnjs.cloudflare.com/ajax/libs/jquery.SPServices/2014.02/jquery.SPServices-  2014.02.min.js" type="text/javascript"></script> <script type="text/javascript" src="//code.jquery.com/ui/1.11.3/jquery-ui.js"></script>  <script type="text/javascript">  $(document).ready(function() {    var defaultuser = "kumar, brishal"; $('input[title="Project manager"]').val(defaultuser);     });  </script>


I have several Boot CD's/DVD's where I'm able to make a bootable USB-stick and put into it. But I can do this separately only. Is it possible to merge several bootable CD's/DVD's into a single bootable USB-stick where I can choose which system to boot from? I'll be happy for a good link, or if you just tell me the steps with the right expressions that i can google.


Can a circular polariser be used with a UV filter?

I recently bought a new circular polariser and found an old UV (Haze) filter from the '90s from an old camera of ours.   I was wondering whether there are any adverse effects of combining these two filters together; however I have not noticed any oddities in any pictures that I have took recently (after the addition of the UV (Haze) filter).


Just installed ubuntu 14.04 but after restart it wont boot

I used a live USB to install Ubuntu 14.04 and completely erase windows 8.1, the installation went fine but when I restarted the computer Ubuntu wouldn't boot from my HDD, instead it came up with try Ubuntu or install Ubuntu so I restarted without the live usb plugged in and I got an error message Reboot and select a proper boot device or insert boot media in selected boot device and press any key.  I read a lot of posts about people that had similar problems but so far none of the solutions that worked for them have worked for me.  I also ran boot-repair but that didn't fix the problem either.   Here is the link from boot-repair   Please any help would be appreciated.  My laptop is a Toshiba Satellite U50D-A notebook with AMD A6-5200 processor


how to pass module/method name as command line argument python 2.7.10

I am trying to find a way to add method name as an argument in command line. I am using argparse module in python 2.7.10.  def create_parser():     parser = argparse.ArgumentParser(description='add method name')     parser.add_argument('--method_name', help='pass method name to be used') return parser  def foo():     return "I am here."  def bar():     return "I am not here."  def where_are_you(method_name):     return method_name()  def main():     return where_are_you(args.method_name)  if __name__ == '__main__':     main()   I am trying to call one of the methods thru command line and getting this error:      "TypeError: 'str' object is not callable." Please guide me here I am new to python.


How do I include nulls during comparisons in SQL Server?

So basically in SQL Server a NULL means there is no value and thus can't be compared which returns some unexpected results.  For example, the following query doesn't return rows where value IS NULL but I want it to:  SELECT * FROM table WHERE   (value != 26)   AND date IS NULL   AND last_modified >= '5/21/2014'   I understand I can do the following as a workaround but seriously? Having to add parentheses and check if is null for every single field every single time I want to include it? Seems ugly, not intuitive and crazy.  SELECT * FROM table WHERE   (value != 26 OR value is null)   AND date IS NULL   AND last_modified >= '5/21/2014'   I mean I know NULL is not a value and thus can't be compared but can't you infer that it is, in fact, definitely not 26? If 26 is something and NULL is nothing and nothing is not something then NULL is not 26. Seems logical to me.  Does anyone know how I can, in a cleaner way, include nulls in my results when using comparisons without having to include an explicit check each and every time. Also turning off nulls on my tables is definitely not an option.  Edit:  My real problem of why I don't want to do it the way I showed was not exposed. So here goes. I am writing a program that let's you build queries to database tables and let's the user dynamically create filters and such which essentially at the end of the day constructs a SQL statement and gets the results to display to the user. The fields chosen by the user can be any and/or all fields in a given database and if I have to literally put that ISNULL check on every single field that would be really inefficient and make looking at the SQL super ugly. My program is table-definition-agnostic meaning I don't care what's in your table and don't want to know what your table's definition is. I just want you to pick a table, choose some fields to filter on with equals, not equals, in, not in, etc ... and then click a button to view the results of that request.


Proving the sum of two independent Cauchy Random Variables is Cauchy

Is there any method to show that the sum of two independent Cauchy random variables is Cauchy? I know that it can be derived using Characteristic Functions, but the point is, I have not yet learnt Characteristic Functions. I do not know anything about Complex Analysis, Residue Theorem, etc.   I would want to prove the statement only using Real Calculus. Feel free to use Double Integrals if you please.   On searching, I found . However, I was wondering if I could get some help directly on the convolution formula:  $$f_Z(z)=\int_{-\infty}^\infty f_X(x)f_Y(z-x)\,dx=\int_{-\infty}^\infty\frac{1}{\pi^2}.\frac{1}{1+x^2}.\frac{1}{1+(z-x)^2}dx\tag{1}$$  Here I have supposed that $X,Y$ are Independent Standard Cauchy. But I think the general formula can be derived easily after some substitutions. I need some help on how to proceed from $(1)$.  EDIT: Just as what the hint in the hyperlink said, I got the answer using that hint. However, I am not quite sure that the hint is algebraically correct. Maybe there has been some typing mistake in the book.


What are some of the best books on Representation theory for a beginner? I would prefer a book which gives motivation behind definitions and theory.


How to run firefox and firefox ESR simultaneously

The main reason I want to use firefox ESR is to use a proprietary database tool for work that only allows oracle-java based web logins for linux (or a windows only thin client). I also want to use the full version of the outlook web application which only works in firefox. I don't want to run the NPAPI plugins for normal web browsing and email.   I have the repo version of firefox installed and firefox ESR installed in /opt/firefox and linked to /usr/local/firefox-esr  When I run firefox any attempt to run firefox-esr either brings up a window without the NPAPI plugins.   If I try running with the --new-instance or --no-remote options I receive the following error:  Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system.   Regardless which one I start first, I can only open that one, and get the above error if I attempt to sidestep.  What makes this an especially annoying problem is that I often have to respond to emails that I need to access the database to deal with. So either I close and open many windows.


Minecraft 1.7.10 crashes when I attempt to open a world

I want to play minecraft in 1.7.10 but after launching it through the launcher and i try to open a server or single player world it crashes  ---- Minecraft Crash Report ---- // This is a token for 1 free hug. Redeem at your nearest Mojangsta: [~~HUG~~]  Time: 3/18/15 6:11 PM Description: Ticking screen  java.lang.IndexOutOfBoundsException     at java.nio.Buffer.checkIndex(Buffer.java:540)     at java.nio.DirectIntBufferU.get(DirectIntBufferU.java:253)     at bma.a(SourceFile:271)     at bma.a(SourceFile:220)     at bao.a(SourceFile:1694)     at bao.a(SourceFile:1652)     at bjb.a(SourceFile:125)     at hd.a(SourceFile:70)     at hd.a(SourceFile:13)     at ej.a(SourceFile:174)     at bcx.e(SourceFile:78)     at bao.p(SourceFile:1343)     at bao.ak(SourceFile:774)     at bao.f(SourceFile:728)     at net.minecraft.client.main.Main.main(SourceFile:148)   A detailed walkthrough of the error, its code path and all known details is as follows: ---------------------------------------------------------------------------------------  -- Head -- Stacktrace:     at java.nio.Buffer.checkIndex(Buffer.java:540)     at java.nio.DirectIntBufferU.get(DirectIntBufferU.java:253)     at bma.a(SourceFile:271)     at bma.a(SourceFile:220)     at bao.a(SourceFile:1694)     at bao.a(SourceFile:1652)     at bjb.a(SourceFile:125)     at hd.a(SourceFile:70)     at hd.a(SourceFile:13)     at ej.a(SourceFile:174)     at bcx.e(SourceFile:78)  -- Affected screen -- Details:     Screen name: bcx  -- Affected level -- Details:     Level name: MpServer     All players: 0 total; []     Chunk stats: MultiplayerChunkCache: 0, 0     Level seed: 0     Level generator: ID 00 - default, ver 1. Features enabled: false     Level generator options:      Level spawn location: World: (8,64,8), Chunk: (at 8,4,8 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)     Level time: 0 game time, 0 day time     Level dimension: 0     Level storage version: 0x00000 - Unknown?     Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)     Level game mode: Game mode: survival (ID 0). Hardcore: false. Cheats: false     Forced entities: 0 total; []     Retry entities: 0 total; []     Server brand: ~~ERROR~~ NullPointerException: null     Server type: Non-integrated multiplayer server Stacktrace:     at bjf.a(SourceFile:289)     at bao.b(SourceFile:1972)     at bao.f(SourceFile:737)     at net.minecraft.client.main.Main.main(SourceFile:148)  -- System Details -- Details:     Minecraft Version: 1.7.10     Operating System: Windows 7 (amd64) version 6.1     Java Version: 1.8.0_25, Oracle Corporation     Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation     Memory: 71006800 bytes (67 MB) / 189317120 bytes (180 MB) up to 1060372480 bytes (1011 MB)     JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M     AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used     IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0     Launched Version: 1.7.10     LWJGL: 2.9.1     OpenGL: GeForce GTX 750 Ti/PCIe/SSE2 GL version 4.4.0 NVIDIA 344.75, NVIDIA Corporation     GL Caps: Using GL 1.3 multitexturing. Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported. Anisotropic filtering is supported and maximum anisotropy is 16. Shaders are available because OpenGL 2.1 is supported.      Is Modded: Probably not. Jar signature remains and client brand is untouched.     Type: Client (map_client.txt)     Resource Packs: []     Current Language: English (US)     Profiler Position: N/A (disabled)     Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used     Anisotropic Filtering: Off (1)


Two svchost.exe processes keeps occpying 25% (sum) CPU on Windows 10 Pro 1709

I got a new Thinkpad T470 laptop, which is supposed to have "10+ hours of battery life". However, there are these two svchost.exe processes that keep taking a sizable bite on my CPU.   My guess for now is that: these two processes are started by the WiFi Hotspot "service".   Details of the two processes  Image Name                     PID Services ========================= ======== ============================================     svchost.exe                   4144 BFE, CoreMessagingRegistrar, MpsSvc     svchost.exe                  14108 SharedAccess   I used tasklist /SVC to elicit the above info, and used  to monitor the CPU usage. What follows is a GIF on how persistent these two processes are (screen-recorded from Process Lasso, a paid piece of software).   Failed Attempts  Here goes a list of failed debugging attempts:   After spending a good hour with Microsoft Support people through a remote session, I was advised to , by disabling all services. They also said I don't have to manually disable all startup processes/items in the Task Manager. It did not help:   Indeed, the Microsoft people's job is done after the "clean boot": s\he is no longe connected and I can no longer bother him or her; yet, what I get from the "clean boot" is nothing but a crappy solution:   For sure, these two processes are no longer bothering me, upon system start; However, when I want to start the WiFi Hotspot, they are back again. And, the WiFi Hotspot just gets stuck there: always in progress, and no other devices can connect to it.   Potentially, this may have to do with a third party software Connectify. Uninstalling it does not help: starting WiFi Hotspot through Windows Setting should no longer generate a usable WiFi, and the two svchost.exe process should still be running in the background, at all times. I have tried to run Windows Updates, and Thinkpad Driver updates. It does not help. And, the system is Windows 10 Pro 1709.  I have also tried to manually stop the two services. Of course, this only helps with generating a "Blue Screen" and entails the BOIS to reload. (A system restart thereby follows.)   Question: does it cost 20% CPU to run WiFi Hotspot?  I need to generate a WiFi Hotspot for personal use, in my work environment. There is a piece of reading device that I literally "live on", which needs a home wifi to sync with the PC. Preferably, this "home wifi" ought to be running 24/7, through the WiFi Hotspot.  And, if it should not cost one 20% CPU to simply run a WiFi Hotspot, what should I do to debug this consistent CPU usage from the two aforementioned svchost.exe processes?  Question: how to resume WiFi Hotspot connectivity?  As answered in this , one can disable all internet sharing services and get away with a lower CPU usage. Sure, this helps, but does not solve my issue: I would like to have a WiFi Hotspot running, at all times, with lower CPU usage. Disabling everything is not an equivalent to a satisfactory solution.  To whom that has closed this question, please enable the Answer button for me. I will provide more info on why this happened (tentatively a driver issue), and my tentative solution.


What is this sentense structure 'If you had ....., I would have been .........'

I came across this sentence on stack exchange and it confused me.     'If you had called me 10 minutes ago, I would have been sleeping.' on    What is the structure of the above sentence called?   Why 'If you had called me? Can it be replaced with 'If you called me?'  I thought 'had called' is past perfect which means it happened before another event in the past. But in this case, it sounds like 'sleeping' came before.


This question arose in a seminar today about the solar wind... This is my vagueish understanding of the problem - please correct if you see errors! The 'classical' picture of atmospheric electricity is that the Earth as a whole is neutral, but that thunderstorms maintain a voltage of around +300kV at the electrosphere with respect to the Earth's surface, with a current of around 1 kA slowly discharging around 500 kC of total charge separation. The solar wind is supposed to neutralise any net charge that might be there between the Earth as a whole and the solar wind. However, positive and negative charges in the solar wind are differently trapped in the van Allen belts, from which they can then descend to the Earth's atmosphere, which implies that a net charge can be developed due to this differential leakage. This begs the question of whether there are any estimates of the total net charge. I've hunted in the literature but have found little useful material other than Dolezalek's 1988 paper:  Can anyone offer an explanation, or point me to some more relevant papers?


Today I am seeing this on my google chrome & Mozilla  Firefox browser both..


Converting random 6-faced dice results to decimal base

I want to get random decimal digits out of a 6-faced die.  Let's say the die is fair, with an equal probability for each outcome. (But feel free to share any consequences of that not being true, if you feel like it.)  I will represent the outcome of a die roll as a base-6 number:   In base-6 there are only 6 possible digits: $\{0,1,2,3,4,5\}$. The die has faces numbered 1 to 6. Face $f$ corresponds to digit $f-1$.   Thus, I can represent as many die rolls as I like with a base-6 number:   If the die is rolled once:   Let's say the die stopped on face $5$. The final base-6 number will be $4$.  If the die is rolled twice:   Let's say the die stopped on face $5$. And then on face $3$. The final base-6 number will be $42$.  If I roll the dice 10 times:   Let's say the die stopped sequentially on faces $5$, $3$, $4$, $6$, $2$, $3$, $3$, $3$, $2$, and $4$. The final base-6 number will be $4235122213$.    Since I want decimal digits, I need to convert to base-10.   Base-6: $4235122213$ Base-10: $44753985$   For any given number of die rolls, how many different combinations exist? If there are $r$ die rolls, the total of possible combinations is $6^r$.   $r$ rolls — $6^r$ different combinations. $0$ rolls — only $1$ combination. $1$ roll — $6$ different combinations. $2$ rolls — $36$ different combinations. $3$ rolls — $216$ different combinations. $4$ rolls — $1296$ different combinations. $5$ rolls — $7776$ different combinations. $6$ rolls — $46656$ different combinations. $7$ rolls — $279936$ different combinations. $8$ rolls — $1679616$ different combinations. $9$ rolls — $10077696$ different combinations.   $n_r$ ($\in \mathbb{N_0}$) is the number obtained after $r$ die rolls through the process described previously: "If the die is rolled once, twice, ..."  It is impossible for $n_r$ to reach the number of possible different combinations ($6^r$). It will be always short by least $1$:  $$ 0 \leqslant n_r < 6^r $$   $r$ rolls — $n_r$ never surpasses $6^r-1$. $0$ rolls — $n_r$ never surpasses $0$. $1$ roll — $n_r$ never surpasses $5$. $2$ rolls — $n_r$ never surpasses $35$. $3$ rolls — $n_r$ never surpasses $215$. $4$ rolls — $n_r$ never surpasses $1295$. $5$ rolls — $n_r$ never surpasses $7775$. $6$ rolls — $n_r$ never surpasses $46655$. $7$ rolls — $n_r$ never surpasses $279935$. $8$ rolls — $n_r$ never surpasses $1679615$. $9$ rolls — $n_r$ never surpasses $10077695$.   I can never trust the leftmost nor the rightmost digit (fringe digits), since the possible values are potentially restricted.   For $0$ rolls, the outcome is always $0$. For $1$ roll, the fringe digit never surpasses $5$. For $2$ rolls, the leftmost digit never surpasses $3$, and the rightmost, $5$. For $3$ rolls, the leftmost digit never surpasses $2$, and the rightmost, $5$. For $4$ rolls, the leftmost digit never surpasses $1$, and the rightmost, $5$. For $5$ rolls, the leftmost digit never surpasses $7$, and the rightmost, $5$. For $6$ rolls, the leftmost digit never surpasses $4$, and the rightmost, $5$. For $7$ rolls, the leftmost digit never surpasses $2$, and the rightmost, $5$. For $8$ rolls, the leftmost digit never surpasses $1$, and the rightmost, $5$. For $9$ rolls, the leftmost digit never surpasses $1$, and the rightmost, $5$.   The other digits seem perfectly random to me though. Am I wrong?


How to find a sum of the series? $ S=\sum_{n=1}^\infty\left(\frac{\sin nx}{n}+\frac{\cos nx}{n^2}\right) $

How to find a sum of the series?   $$ S=\sum_{n=1}^\infty\left(\frac{\sin nx}{n}+\frac{\cos nx}{n^2}\right) $$   I tried to do something like that: $$ \begin{aligned} &z=\cos x+i\sin x\\ &S=\sum_{n=1}^\infty\text{Im}\left(\frac{z^n}{n}\right)+\sum_{n=1}^\infty\text{Re}\left(\frac{z^n}{n^2}\right) \end{aligned} $$ However, $\sum_{n=1}^\infty\frac{z^n}{n^2}=\text{Li}_2(z)$, and I have no idea what $\text{Re}(\text{Li}_2(z))$ is here.  So, I'd be very grateful if someone pointed out the right way of solving this problem.


Could you tell me what are the Data Extensions used by Web & Mobile Analytics where i cand find data collected from Javascript in website? I should retrieve data using firstly a SOAP UI Call, then a SQL query in a child Business Unit of MC Account.


accidentally deleted external hard drive

I am new to linux(ubuntu) and made my first mistake. Hoping for some help. I accidentally formatted usd hard drive (sudo mkfs.ext4 /dev/sdb1). I have been searching and found that testdisk might help? I've also read a few thing that mentioned restoring via superblocks. Has anybody gone through this or know the best way to fix it?  I appreciate the help.  thank you  Nick


Infinite summation of reciprocal of Binomial coefficients

When I was playing with Binomial coefficients. I got an interesting problem. It is very nice formula. The problem is  $$\large \sum_{n=0}^{\infty} \dfrac{1}{\binom{2n}{n}}$$  where $\binom{2n}{n}$ represents the number of ways of selecting $n$ different things from $2n$ different things. I will provide the solution below.


How do you apply a texture to select faces of a mesh

I have build a basic house but I would like to use different textures for the roof and walls. Here is what I have now.     The brick texture is on the roof when i want it to be a different texture


The meaning of dot centered vertically, as in $3\cdot 5$

I just went to a site to practise some maths as I am studying some maths on my OU course in computing and IT and I ran into some symbols that I did not understand  The questions were   solve $16+14/2+3\cdot 5-11$ (the point was placed halfway between the top and bottom of the numbers) $(11-5)\cdot (63-59+6)/12$, once again point is halfway between top and bottom   Can someone explain what this means if it is different to a decimal point?  Also this symbol was used in other questions $|$ and I was wondering what this meant as well  In context it was the number $-5$ can be written as and one answer was $|-5|$ and another choice was $-|-4|-1$


I'm a girl, younger than 16 years of age, and live in a country where getting divorced is considered VERY BAD in the society for both the parents and the children. My father can't cope up with my mother and we hear an argument daily where he almost every time says to give a divorce to my mother. My mum is very egoistic,and doesn't understand that we could perfectly live happily and there is nothing wrong with dad (she thinks he has an affair although he doesn't and has explained to her like a gazillion times...). If they get divorced it would have a greater effect on me and my brother's life than theirs as they are both about the age of 40.  WHAT DO I DO???!!! I'm so confused and tensed and scared.... Help me, PLEASE!


Just got an interview in which I had to explain the following code: private static int s = 1;  private static async Task Main(string[] args) {     var tasks = new List<Task>();      Action a = () => s++;      tasks.Add(Task.Factory.StartNew(a));     tasks.Add(Task.Factory.StartNew(a));     tasks.Add(Task.Factory.StartNew(a));     tasks.Add(Task.Factory.StartNew(a));      await Task.WhenAll(tasks);      Console.WriteLine(s); }  And at a first glance, I have answered that s will 1 because of the closure mechanism and creating an additional class to encapsulate the field s and work on it in the local scope just like in the code: private static async Task Main(string[] args) {     var tasks = new List<Task>();      Action a = GiveMeAction();      tasks.Add(Task.Factory.StartNew(a));     tasks.Add(Task.Factory.StartNew(a));     tasks.Add(Task.Factory.StartNew(a));     tasks.Add(Task.Factory.StartNew(a));     await Task.WhenAll(tasks); }  public static Action GiveMeAction() {     int i = 1;     return () => Console.WriteLine(++i); }  Since closure will be translated as something like that: [CompilerGenerated] private sealed class <>c__DisplayClass8_0 {     // Fields     public int i;      // Methods     internal void <MyClosureCreationMethod>b__0()     {         int i = this.i;         this.i = i + 1;     } }  The value will be passed by value. My question is: why the static field s is changing globally and not locally in <>c__DisplayClass8_0?


Windows 10 Hangs in VirtualBox in ubuntu 16.04

I am trying to install Windows 10 (64 bit) OS in Virtualbox in Ubuntu 16.04. When I run the setup from virtual box to install Windows 10, it hangs at the Windows logo screen and never proceeds further and shows NO error messages. Check the screenshot  What's the problem here?


In my freshly installed Ubuntu 20.04 LTS, Ubuntu Software is not loading properly.  It is loading only Editor's Picks but nothing else. Installed tab is empty and search is not working as well. My internet connection is perfectly working and I am not using any firewall.


Stop macOS from creating/storing previous versions of a document

macOS creates a history or previous version of each any every document/file I edit and this not only happens across the os but also happens across every mac apps.  These version files takes up huge chunks of unnecessary storage so how can I stop macOS from making this histories/previous document versions and storing it on your HDD.  I don't have Time Machine backup enabled and it still stores and saves the previous versions of a file!


How do I deny a particular user from getting root ( through su ) in a terminal by changing the /etc/pam.d/su ? Pam based controlling is required

There are two users in ubuntu (let's call them user1 and user2). Currently, user1  can get access root access using the below commands:  user1@sai:~$ su Password:  root@sai:/home/user1#   However, I want to deny user1 from getting root access, and instead allow user2 to get root access through sudo when desired by modifying the Pam configuration file in /etc/pam.d/su file.  How can I do this?


Do I need a visa to travel to South Africa with a Germany refugee travel document? If yes, what is the requirement for the visa application at the South African embassy?


Inserting a description in mysql database with HTML entities - php

I have some descriptions, which looks like :   "Szukamy osoby chc\u0105cej pracowa\u0107 w zespole pe\u0142nym pasjonat\u00f3w. Poprzez rozwi\u0105zywanie zg\u0142aszanych do nas incydent\u00f3w kreujemy szcz\u0119\u015bcie u naszych wsp\u00f3\u0142pracownik\u00f3w :-). Nie ograniczamy si\u0119 do pojedynczej linii wsparcia. Bierzemy odpowiedzialno\u015b\u0107 E2E za nasze us\u0142ugi, serwery, sie\u0107\u2026.jak i za to, aby spotka\u0107 si\u0119 z u\u017cytkownikami, wys\u0142ucha\u0107 ich i wsp\u00f3lnie tworzy\u0107 najlepsze \u015brodowisko pracy.<\/p><p>Szukamy osoby, dla kt\u00f3rej wa\u017cna jest dobra atmosfera w pracy, chc\u0105cej wsp\u00f3\u0142tworzy\u0107 zesp\u00f3l na kt\u00f3ry mo\u017cna zawsze liczy\u0107."   As you can see this description contains, special characters like " \u00f3w " etc. When I try to insert it in the database, the sql insert query ignore the test after these characters wherever they are detected. How can I overcome this problem ? so that I can insert full texts.  I did something like !     if (isset($_POST["add_jobdets"])) {    $job_head = $_POST["job_head"];   $job_details = html_entity_decode($_POST["job_details"]);   $refNo = $_POST["refNo"];    $jobs_dets = "INSERT INTO jobs_details VALUES (NULL,'$job_head','$job_details','$refNo','now()')";   $con - > query($jobs_dets);   }     Even Tried this but Failed :    if (isset($_POST["add_jobdets"])) {     $jobs_dets = $con - > prepare("INSERT INTO jobs_details (jd_id,job_head,job_details,refNo,jd_time) VALUES (NULL,?,?,?,'now()')");   $jobs_dets - > bind_param('sss', $job_head, $job_details, $refNo);     $job_head = $_POST["job_head"];   $job_details = $_POST["job_details"];   $refNo = $_POST["refNo"];      $jobs_dets - > execute();  }


Power calculations, logistic regression with continuous exposure--cohort

I'm trying to estimate power in a logistic regression with a continuous exposure in a cohort study (ie, the ratio of the sampling probabilities is 1). I have population cumulative incidence (probability) and population exposure variability and exposure mean and an expected odds ratio. I also have a total sample size.  I'm using R and it seems like Hmisc::bpower is only for logistic regression with binary exposure and I can't seem to find any packages that estimate binomial power with continuous exposure.  I've attempted the following simulation but it's quite slow given my total sample size and I'm not sure if it's right:  p <- vector() betahat <- vector() for(i in 1:1000){ n <- 40000  #total sample size intercept = log(0.008662265)  #where exp(intercept) = P(D=1) beta <- log(1.4) #where exp(beta)=OR corresponding to a one unit change in xtest xtest <- rnorm(n,1.2,.31)  #xtest is vector length 40,000 with mean 1.2 and sd .31 linpred <- intercept + xtest*beta #linear predictor prob <- exp(linpred)/(1 + exp(linpred)) #link function runis <- runif(n,0,1) #generate a vector length n from a uniform distribution 0,1 ytest <- ifelse(runis < prob,1,0)  #if a random value from a uniform distribution 0,1 is less than prob, then the outcome is 1.  otherwise the outcome is 0 coefs <- coef(summary(glm(ytest~xtest, family="binomial")))  #run a logistic regression p[i] <- coefs[2,4] #store the p value betahat[i] <- coefs[2,1] #store the unexponentiated betahat }  mean(p < .05) #power  exp(mean(betahat)) #sanity check, should equal 1.4--it does   Is there anything wrong with this approach?  One concern of mine is that the cumulative incidence (ie, probability of event over the given time period) comes from a population that did not have 0 exposure.  In fact, it's reasonable to assume that the value i'm using for an intercept is actually from a population that has an exposure variability similar to mine. In that case, how would I estimate the unexposed probability given an odds ratio (and other information that I would find in say, a published paper) to use in my power calculation?


I wanted to get theta below argmax in the middle . I used the following code:  \usepackage{amsmath,amssymb,graphicx,enumerate,algorithm} \begin{document} $\theta_i$ = $argmax_{\theta} Q(\theta, \theta_i)$ \end{document}


Evaluating $\int \frac{2\ dx}{\sin x \cos x}.$

Evaluate the following $$\int \frac{2\ dx}{\sin x \cos x}.$$


How to detect dead code on running environment?

A codebase was delivered to me for deploy and maintenance. It happens to be a very messy codebase that grow without code cleaning. So, I suspect that there is about of 80% of dead code there. By dead code here I mean legacy code that is not in use anymore, but is there sitting on the codebase. This number is more a felling than a measurement, the application is simple, there is about 3ain tables and a single flow, I've been tweaking for some months ... Also we have low low low traffic, so no millions of requests per second ...  I want to use something like code coverage to get a heat map of the code, so I can eliminate code that is for sure not in use,  did anyone tried something like that? What are the options?


Why reference of parent class is used to call an overridden method in Java?

I am learning about method overriding in Java. Below is an example of method overriding.  class ABC{    public void myMethod(){     System.out.println("Overridden Method");    } } public class XYZ extends ABC{     public void myMethod(){     System.out.println("Overriding Method");    }    public static void main(String args[]){     ABC obj = new XYZ();     obj.myMethod();    } }   When an overridden method is called through a reference of parent class, then type of the object determines which method is to be executed. Now consider below :  ABC obj = new ABC(); obj.myMethod(); // This would call the myMethod() of parent class ABC (1)  XYZ obj = new XYZ(); obj.myMethod(); // This would call the myMethod() of child class XYZ (2)  ABC obj = new XYZ(); obj.myMethod(); // This would call the myMethod() of child class XYZ (3)   If (2) and (3) gives same output : Overriding Method, then why use (3)? We could just use (2) right?  I am new to Java, so I will tend to ask many doubts! Please help! Thank you!


What (if any) state did energy exist in prior to the big bang?

I am comfortable with the idea that 'pure energy' cannot be observed, only different forms in which it manifests. I can also understand that matter-antimatter interactions result in fundamental particles that ultimately conserve energy. So forgive my amateur question, but is there any conception of what energy was like prior to the big bang?   It implicitly seems that it would still have existed as particles of some kind, but my understanding is there would have been no space for them to exist in. That leaves me in a position where it seems that it might have just been energy in a state that perhaps can't be observed in our universe, which seems eerily similar to the idea of what 'pure energy' might be. Is it conceived to have been in some undefinable state, or did it exist in a way similar to how it manifests in our observable universe?


Wireless connection fails every few minutes

(Newbie) Ubuntu 20.04 My wireless network just won't stay online. The signal is strong and the wifi worked fine on Windows and Linux, but neither of the 2 versions of Ubuntu that I've tried (21.04 + 20.04) will maintain connection. After screwing up by attempting to update with an unstable connection, I ended up freshly reinstalling it today, but it's dropping offline more frequently every time I reinstall (every minute now). To reinstate connection I need to switch the wifi off for a few seconds and back on again. It won't reconnect by itself. All I have to work with is the basics that Ubuntu came with because I can't stay online long enough to download or update anything. From what info I could find between forums, I suspect that my computer is one of the unlucky ones that Ubuntu's network manager just doesn't get along with. I think I may need an alternative network manager, but downloading anything isn't an option. ipv6 is off, I always make sure it's off after every OS installation because Virgin media (internet provider) doesn't support it. The modem is too far to run an ethernet cable, but the wifi repeater gives it a good signal. I've been searching the web for answers all day and I haven't been able to find a solution that'll work in my situation. Please help!


Is there a single list of rules governing Stack Exchange sites (and if so, whre is it?)? More specifically, I'm interested in hard rules that are automatically enforced by the machine, or well-delimited rules that moderators are expected to follow? This is inspired by having seen questions that are notated (under review) "This question is too old to migrate" -- which suggests a rule. I also understand that there is a limit on the number of custom reasons a Beta site can have for closing questions. I basically am interested in rules embodied in the code, but extend that to rules that moderators have to enforce, in case it's too hard to write code to do it automatically. I am totally not asking about rules defining good and bad questions.


What is the maximum volume of a cylinder that can fit in a sphere of a constant radius?

The first question that comes into my mind here is whether any cylinder that touches(at 4 pts) the circumference of the sphere and does not go out of it, has equal volume?   Second, how do i mathematically limit the volume of the cylinder to be less than that of a sphere? Squeeze theorem?   Please help, thanks!


Exception in thread “main” java.lang.NullPointerException error

I am having a problem at a Java program. Exception in thread "main"  exception in thread main java.lang.nullpointerexception at VenueHireSystem.main (VenueHireSystem.java:27)  is the error that I'm getting. I could really use some help, since i am stuck hours on this spot... import java.io.FileNotFoundException; import java.io.FileReader; import java.util.Scanner;   public class VenueHireSystem {      public static void main(String[] args) {            Scanner sc = null;           try           {               sc = new Scanner(new FileReader("test.txt"));             }           catch (FileNotFoundException e) {} /*        finally           {               if (sc != null) sc.close();           } */                             Manager VenueManager = new Manager();                      String info;           String key;                      while (sc.hasNextLine() && sc.hasNext()){               key = sc.next();               info = sc.nextLine();               if (key.equals("Venue")){                   VenueManager.addVenueAndRoom(info);               } else if (key.equals("Request")){                   VenueManager.RequestBooking(info);               } else if (key.equals("Change")){                   VenueManager.ChangeBooking(info);               } else if (key.equals("Cancel")){                   VenueManager.CancelBooking(info);               } else if (key.equals("Print")){                   VenueManager.PrintBooking(info);               }           }                      sc.close();     }  }


Why is L2 regression good for handling multicollinearity?

Looking for an intuitive explanation, thanks.


Protecting sensitive data when giving the laptop to a technician

Suppose that my laptop does not boot and I have to give it to a technician for repair. This gives the technician access to my hard-drive and all the material in it.  I can take out or encrypt the hard-drive, but then the technician will not be able to boot in order to validate the problem or verify that the problem was solved.  Is there a way to let the technician freely boot into my machine (using a guest account), and at the same time, prevent the technician from viewing personal data on my computer?


Identify a photo filter or a post-processing technique

Sometimes I come across photos that have some effect/filter applied to them, and I cannot understand/explain what that is. It looks really attractive, and I would like to be able to reproduce this effect in Photoshop or alike. The effect that I am looking for can be seen, for example, . Scroll down to the photos below “About” and “Schedule.”  I would be grateful if somebody could tell the name of this effect/filter and maybe share some recipe or just a link where I could read about it.  Thank you!  Regards, Ivan


If I find a Bobblehead early will I be unable to raise my SPECIAL to 11?

I know if you have a Strength of 10 and find the Strength Bobblehead you can get to 11, but what if I find the Bobblehead earlier. Say I find it when my Strength is 9. Do I have  Strength 10 or  Strength 9+1? Basically, should I wait to go searching for Bobbleheads until I've maxed out a stat, or will I be able to get them all to 11 eventually regardless of when I find the Bobbleheads?


I am working on a problem that requires finding the line integral of a vector field along a curve. The vector field is defined by the function:  $$F(x,y)=\left(\frac{y}{x^2+y^2},\frac{-x}{x^2+y^2}\right)$$  which is well defined everywhere except the point $(0,0)$, where it is not defined. The line integral to be done is across the curve defined by:  $$(\cos(t),-\sin(t)),t\in[0,2\pi]$$  The curve is closed, as can be seen and the vector field is conservative as it can be shown to be the gradient of the function $U(x,y)=\arctan\left(\frac xy\right)$ This means that the line integral should be $0$, as the line integral of a conservative vector field over a closed curve is $0$. However after computing it by hand it turns out to be $2\pi$. Why is this the case?