I have completed high-school with good grades and due to some unavoidable reasons can’t go to university. Currently, I am self-studying mathematics. My interests include single and multi-variable calculus, linear algebra, probability, discrete mathematics and graph theory. I have few books on these subjects. For example: Apostol’s and Spivak’s calculus books, Ross probability etc. My problem is I read theory from these books and try to solve exercise questions, but when I can’t find solutions to a problem I have nowhere to look for step-by-step explanation to that problem. Most of the books I have don’t have detailed explanations or solution manuals. And as live on the remotest part of a developing country, I have no teacher and professors to ask questions.  And I have tried Chegg subscription but most of the solutions they have are disappointing and cryptic if not downright horrible. How should I deal with this situation? I really want to learn math. Please help me.

I've been lurking on this site for several months, and as someone studying higher mathematics independently (i.e., outside of a college/institutional setting), this forum has probably been the best reference for gleaning general information about college-level math.  However, recently I've come to realize that few of the major/popular math textbooks tend to have solutions to the exercises contained within them or available for free/online. As someone without access to a professor or peers who can check the accuracy of my answers, working through book solutions becomes very tedious. How do I know if I am getting the right answers and thus understanding the material? I know people are encouraged to post here for help with challenging problems, but it doesn't seem appropriate to post in a forum such as this to simply check the veracity of answers. In addition, certain books (e.g., Pugh's Real Mathematical Analysis) contain hundreds of exercises throughout the text, and it would be neither plausible nor acceptable to constantly ask for help with problem after problem for an entire textbook.  I am not in school nor do I plan to enroll anytime soon, so there's not really an option of waiting until college to talk things over with someone more knowledgeable about mathematics. I am learning math out of pure curiosity and not in preparation for future classes or career goals, and while there are a plethora of resources available to the independent student of mathematics now more than ever before, being able to assess how well the material is being absorbed remains a difficult obstacle to overcome.


Can anyone please explain why CMD pings a different IP address than the one I am searching for?

I have a security system and the network setting only allows a three-digit IP address. I can't set it to 192.168.2.100, instead I have to use 192.168.002.100.  Are these two IP addresses different? Do I need to set my router's LAN to be all 192.168.xxx.xxx in order for this to work correctly? I can't find any solid information about this.


I just signed in to MySQL and am trying to connect to a database so that I can begin to write tables. My research understanding is that you use "use" followed by the database name, and end with ;  The database name that I am trying to connect to is 3 words with space in between them (i.e., A B Database)  When I try use A B Database; it says there is a syntax error at the B. Any reasons why this may be happening?

I want to select my particular database in mysql console, but the problem is that my database name has a space in between and mysql ignores the part after the space. For instance, when i give the command:  use 'student registration'   I get the message:  cannot find database 'student'


I'm unable to install my AMD proprietary Drivers in Ubuntu 14.04.5, as fast as I select the "apply changes" in the software properties it reverts back to the open-source drivers.  I opened the the software properties menu through the terminal and this happens when I select fglrx-updates:  unity-control-center: Depends: libpulse-mainloop-glib0 (>= 1:0.99.1) but 1:4.0-0ubuntu11.1 is not installed                       Depends: libpulse0 (>= 1:0.99.1) but 1:4.0-0ubuntu11.1 is not installed                       Depends: libxi6 (>= 2:1.2.99.4) but 2:1.7.1.901-1ubuntu1.1 is not installed   and the same happen when fglrx is selected.  My system is a DELL INSPIRON 15-5555 with an APU A10 8700P. It has Windows 10 installed by default and secure boot. I don't know if this is important but I added anyway.

I have 14.04.5/16.04 or newer and an AMD GPU. I'm not getting the performance I want, and some programs say they need things like OpenCL.  I've heard about fglrx, but if I try to install it on my machine, it breaks and I have no GUI.  Is there anything I can do to get my AMD card working to its full potential?


Construct an Injection between the set of rationals $\mathbb{Q}$ and the set of all integers $\mathbb{Z}$ .  Answer:  Define $ f: \mathbb{Q} \to \mathbb{N} \ $ by $ \ f\left(\frac{p}{q}\right)=|p-q|+1 \ $ , where $ \gcd(p,q)=1$  Clearly $f$ is an injection.  Next, define $ g: \mathbb{N} \to \mathbb{Z}$ by $  g(n)=n  $  Then $ g $ is also an injection.

I want to prove that $\mathbb{Q}$ is countable. So basically, I could find a bijection from $\mathbb{Q}$ to $\mathbb{N}$. But I have also recently proved that $\mathbb{Z}$ is countable, so is it equivalent to find a bijection from $\mathbb{Q}$ to $\mathbb{Z}$?


while asking questions in the sentence do we need to give space between question mark (?) and the sentence.  what is your name?  what is your name ?  which one is correct?

In written English (mainly online) I often come across sentences ending with a question or an exclamation mark with a space before it. Is it always just an error or a typo? Or there are cases when it is a correct English, for example after closing parentheses or some other punctuation marks?


I installed Xubuntu and am not a huge fan of it.   I want Ubuntu back and can't figure out how to make a bootable usb on Xubuntu.  Please tell me my options

How do I make an Bootable Ubuntu USB containing the the latest version of Ubuntu?  For completeness, how would I be able to do this on Ubuntu, Windows, OS X or another Linux distro?


My book states the following, "when a particle, in a stationary state, is bound the expectation value of its momentum is zero" but it never elaborates why.    I know that $$\int\Psi^*(x,t)\hat{Q}\Psi(x,t)dx$$  but why would that necessarily mean that the expectation value of its momentum is zero?

Is it logically correct to assert that the expectation of the momentum $$\langle \hat p \rangle=0$$ for any bound state because it is bound to some finite region? What is the physical interpretation of the fact that $$\langle \hat p \rangle=0$$ in an energy eigenstate $\psi_n(x,t)$  but $$\langle \hat p \rangle\neq0$$ in some superposition state $$\psi(x,t)=c_m\psi_m(x,t)+c_n\psi_n(x,t)~?$$ Here $\psi_n(x,t)$ the eigenstates of the Hamiltonian, for example, in the problem of particle in a box (say).


How do i calculate the value of the following integral--  $$I=\int_{0}^{1} \frac{\ln{(1+x)}}{1+x^2}$$  I tried doing substitutions like $1+x=t$ etc.   I also tried to use the property $\displaystyle\int_{a}^{b} f(x)=\displaystyle\int_{a}^{b} f(a+b-x)$, but didn't arrive at anything fruitful.


I am new in ubuntu so a step by step guide will be highly appreciated. My windows OS laptop crashed with fatal error, it won't even go past the boot. I need a way to install a new OS (hence ubuntu) and to restore whatever I have on my hard drive C:/

I would like to see a full how-to guide on how to install Ubuntu.


So I found this link:  That says its text was taken from a web enhancement for the Tome of Battle, however the link returns a 404 error. Anyone knows if that enhancement is still abailable?

It appears that in anticipation of D&D Next Wizards of the Coast has removed much of the Dungeons and Dragons, 3rd Edition Web content. I didn't perform a thorough search to determine if all the content is removed (e.g. I know the Three Dragon Ante Web enhancement  and the Mind's Eye column about psionic tattoos  are both gone--better not to ask why those are my go-to articles), but it all might be.  What's the best way--and by best I mean both legal and convenient--to continue to access this content?


I'm currently in the final year of my BSc. in physics and the second year of my BSc. in mathematics at a university in german-speaking Europe. I'll have my degrees finished in summer 2018. Eventually, I'd like to end up in theoretical or mathematical physics research (most probably gravitational physics) and would love to experience some time at a foreign university. Firstly, since my university is stronger in the experimental field and has a relatively small theory group and secondly for the sake of broadening my horizon. The US (or generally Northern America) would be particularly interesting, because of the somewhat "more open" research culture, in comparison to a highly bureaucratic and kind of inert (and often poorly financed) apparatus in german-speaking part of Europe (and probably in the whole EU - at least that's my naive perception of it, or am I wrong in this?). I read that the PhD. in the US is a bit different to the one in Europe, e.g.  that a MSc. is kind of integrated in the coursework-heavy first one or two years of a US PhD. Nevertheless, there are some interesting MSc. programs in Europe, e.g. in Edinburgh or at the ETH in Zurich. So, my questions would be (from a rational/scientific-career point of view):  Is it reasonable to go for a PhD. directly after a BSc. in the US? Or would it be more sensible to pursue a MSc. in Europe first and only then head for a PhD. in the US? Small side question for physicists since I'm just researching into this: Which universities in Northern America have a strong gravitational physics department (aside from Stanford and Princeton)?

I start my master studies this fall in quantitative finance/economics in Europe. Since this will just take 3-4 semesters I want to take a look ahead and obviously PhD is one option to do.   So I am wondering if it makes sense to go to the US for PhD, since I will have already a master's degree in two years. I read a lot about the US PhD's which can be started after bachelor and therefore are somehow like a European master & PhD combined.   I saw some PhD programmes from well-known US universities and their curriculum contained almost just courses I will already have in my master. Wouldn't that be a waste of time to repeat them? Specially compared to my country (Switzerland) where a PhD duration is between 3-4 years.  Every input/personal experience will be appreciated.


I didn't see this answered satisfactorily anywhere, so I figured I'd ask.  Every time I go to do something requiring privileges, such as install a program, open restricted folders, etc., I'm prompted for the account password, even though my user account is an administrator.  How do I get it to stop prompting me for my password when doing such actions?

Inspired by this ....  I am the sole person using my system with 12.04. Every time I issue a sudo command; the system asks for the user password (which is good in its own way).  However I was thinking; without activating the root account; how can I execute the sudo commands which will not ask for user password to authenticate.  NOTE: I want to execute sudo command without authenticating via password; only when they are executed via terminal. I don't want to remove this extra layer of security from other functions such a while using 'Ubuntu software center' or executing a bash script by drag-drop something.sh file to the terminal.


I looked around for a good solution to avoid code duplication on each spezialization of a template class.  Here is an example code:  template<class T> class C {     int foo(); }   Now the definition for defaults:  template<class T> C<T>::foo() { return 0; }   Now the spezailization for special templates  template<> C<int>::foo()    { ... do a lot of stuff and return n .... } template<> C<double>::foo() { ... do a lot of stuff and return n .... } template<> C<int>::foo()    { ... do a lot of stuff and return n .... }   Right now I have to duplicate the code for the spezailization. But in general it's the same code.  My questions is: What is the best solution to avoid code duplication here and how can I hide the implementation ? Maybe by using a noname-namespace or an impl-namespace ?  Kind regards, Peter

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


I'm asked to find $\displaystyle\lim_{n\to \infty}\sum_{k=1}^n \left(\frac{k}{n}\right)^n$.  It seems that the sum converges.  I managed to prove that $\forall n,1<\sum_{k=1}^n \left(\frac{k}{n}\right)^n<e$  But I don't know how to prove convergence, nor find the value of the limit.

I can show that the following limit exists but I am having difficulties to find it. It is $$\lim_{n\to \infty} \sum_{k=1}^n \frac{k^n}{n^n}$$ Can someone please help me?


Currently I have setup a local repository using apt-mirror to establish a offline local repository for Ubuntu 16.04.  However, only the official packages are downloaded. I would like to make the third party libraries like Google Chrome, OwnCloud etc. to be also available in my offline local repository.  What changes shpuld I make in the file mirror.list so that apt-mirror can do the job?

Having a local repository can be very useful. It is possible to use rsync to create a repository mirror, but this results in all the releases being downloaded, even older ones and would include files for architectures that might not be needed.  apt-mirror allows one to selectively choose parts of the repository. mirrorkit provides a front-end to apt-mirror.  What is the best way to create a local repository mirror for selected parts of the Ubuntu archives?    For example, one might wish to include:   Main, Restricted, Universe, Multiverse,  All Ubuntu and Lubuntu but exclude other derivatives, such as Kubuntu and Xubuntu. Only AMD64 and i386 but exclude other architectures. Only Trusty Tahr, but not Precise Penguin or Utopic Unicorn.   One might wish to configure the process so that it downloaded from a local mirror, rather than the main archives.  How can I create local repository using apt-mirror and mirrorkit for a selected architecture, release, or Ubuntu variant?


hot water boiler, occasionally opens and closes releasing water to floor. just started doing this (cold weather) does the relief valve need replaced? or is this a common action?

I have a Gas Reliance Water Heater 1212. I found recently (in winter) there is a water dip through the relief valve into a 5 gallon bucket. Sometimes, it can fill the whole bucket. Sometimes, it has no water drip at all.   I can't find the reason why that happens. My two guesses are the usage of water or temperature in the basement. However, I have normal usage -- just laundry, or the dish washer. Nothing odd there. I checked the temperature, and it's sometimes hot, sometimes cold (I live in Pennsylvania). I can't find any pattern.   Can anyone help me on this?


Am I getting it right, that when I'll make a single mesh that represents terrain using unity's built-in 2D Perlin noise function, then I'll be able to somehow add caves using whatever (Perlin worms for example)? Or do I need to find solution with 3d noise?

I have a 3d landscape created from a heightmap. I'd like to "carve" some holes in that terrain. That will allow me to create bridges, caverns and tunnels inside it.    That operation will be done in the game editor so it doesn't need to be realtime. In the end, rendering is done using traditional polygons.  What would be the best/easiest way to do that ? I already think about several solutions :  Solution 1  1) Create voxels from the heightmap (very easy). In other words, fill a 3D array like this : voxels[32][32][32] from the heightmap values.  2) Carve holes in the voxels as i want (easy too).  3) Convert voxels to polygons using some iso-surface extraction technique (like marching cubes).  4) Reduce (decimate) polygons created in 3).  This technique seems to be the most promising for giving good results (untested). However the problem with marching cubes is that they tends to produce lots of polygons thus reducing them is mandatory. Implementing 4) also seems not trivial, i have read several papers on the web and it seems pretty complex. I was also unable to find an example, code snippet or something to start writing an algorithm for triangle mesh decimation. Maybe there is a special decimation algorithm (simpler) for meshes created from marching cubes ?  Solution 2  1) Create some triangle mesh from the heighmap (easy).  2) Apply severals 3D boolean operation (eg: subtraction with a sphere) to carve the mesh.  3) apply some procedure to reduce polygons (optional).  Operation 2) seems to be very complex and to be honest i have no idea how to do that. Also applying many boolean operation seems to be slow and will maybe degrade the triangle mesh  every time a boolean operation is applied.


Still working on cleaning this up but it runs fine. Below is the rough code for a tool that iterates through field rows and clips accordingly to that row's shape. Everything outputs nicely but there are some outputs that do not contain data. What can I add to have arcmap check for shapefiles containing no data and delete them?   Added an if statement to check for empty SHP's but not sure how to define where to have it check the output folder?   import arcpy from arcpy import env  arcpy.env.workspace = r'path\folder'   field = "PARISH" fc = arcpy.GetParameterAsText(0) Name = arcpy.GetParameterAsText(1) Path = arcpy.GetParameterAsText(2) rows = arcpy.SearchCursor(arcpy.env.workspace)   for row in rows:     feat = row.Shape     outputName = Name.replace(" ", "_")     outputField = row.getValue(field)     outputFieldmod = outputField.replace(" ", "_")     arcpy.Clip_analysis(fc, feat, str(Path) + r'/' + str(outputName) + "_" + str(outputFieldmod))  for file in arcpy.ListFiles():     if arcpy.management.GetCount(file)[0] == "0":         arcpy.management.Delete(file)         arcpy.AddMessage('Deleted "{}" because it contains no features!'.format(file))

I have a number of shapefiles in a folder but some of them are empty i.e. there are no rows within the shapefile.   Is there a simple way to find those empty shapefiles using ArcPy?


I want to create a multi boot CD in windows I do this with xboot but is there any program to create multi boot ISO in Ubuntu

What I want is to create a bootable pen drive that shows GRUB menu and I can select any of the several bootable systems from there to install/run. I have several ISO images that I want to install in the USB like Ubuntu, Fedora, System Rescue CD, Windows XP and Windows 7 (The windows versions are optional, mostly am looking for a multi installer for Linux distros, specially Ubuntu version)  The default Startup Disk Creator only works with Linux Images and only 1 at a time (At least for the mean time. If it allows more systems and multiple ISOs it would be awesome)  What method exists that I can use step by step to create a bootable USB Drive with multiple images than can be booted from the USB and selected from GRUB. It must support Windows Images and Linux Images.  Alternatively, is there also a way to have multiple versions of the Ubuntu installation ISO on same USB Drive, such as, when booting from it, I get to choose what Ubuntu version and architecture to install, for example:     BOOT MENU   Ubuntu 12.04 32 Bit   Ubuntu 12.04 64 Bit   Ubuntu 12.10 32 Bit   Ubuntu 12.10 64 Bit   UPDATE: Wanted to add that the English version for the post mentioned by daithib8 is here:


I am new to this meta StackExchange community, So I do not have much knowledge about Winter Bash and earning hat meaning in my profile.   Is is just of fun or really mean something.

I tried to write , but I couldn't find any simple explanation page to link to. I ended up garbling a home-spun description of my own with a not-terribly-helpful image from 2012.  This  puts it better than I can:     As a new user in 2015 can there please be more information about what is WinterBash. The link took me to a bunch of stick figures running around making (I think) numbers (I think its a countdown clock). It doesn't explain the event or even what a hat is. – Ian Miller Dec 4 at 2:58   All I found on Meta was dead links. For example,  was downvoted to -2 and answered with a link to an FAQ page that no longer exists.


I'm looking for some Linux alternative to  (image viewer). At best, it should have all its features, the same controls (both mouse and kbd) or fully adjustable, and be as quick.  In particular (this list covers 95 % of my use cases):   Support for many formats, for both input and output Automatic navigation through the directory with Space and Backspace Thumbnails (T) Batch processing (B) Rotating (R, L) Zoom with Ctrl + mouse wheel or + / - Fullscreen (Enter) Image movement with PgUp and PgDn, Home. End Select a rectagle with a mouse -> Ctrl + Y to crop -> Ctrl + S to save as a PNG file Basic image editation - copy, cut, paste, color filters, text input, basic shapes Immediate startup No need to play video or audio   Etc... IrfanView is something like iPhone amongst image viewers, there's nothing to change ;-)  So - what is as close as possible?  Edit: No virtualization please - IrfanView crashes under  in my environment; running virtualized Windows is even further away from being quick; perhaps it could be Java, but native is native.

is a wonderful freeware Windows swiss-army-knife for image viewing & editing.  For me, the key features are fast viewing, simple editing (crop, contrast, brigthness, rotation, resampling), file operations (delete, copy to folder) and extended image information access (exif data) combined in the same interface. Versatile batch jobs are a very nice bonus.  But unfortunately IrfanView is for Windows only, and isn't . What would be the nearest equivalent for linux?


Like a dummy I deleted the Ubuntu partition on my hdd and restarted my computer. Now when it boots up I get   Error: no such partition Grub rescue>   I don't have a asus repair disk nor a Ubuntu disk I'm using my iPhone as I don't have anything else. Am I screwed or is there a fix?

It's my first time installing ubuntu. I have Windows 7 and 8 before in my laptop (Acer Aspire 4752z). After Ubuntu (12.04) installed in my laptop, the Windows boot loader didn't recognize my Ubuntu so I updated grub from a live USB.   And after grub updated, Ubuntu was booting perfectly but my Windows wasn't listed in the grub menu. So I follow someone instruction to update grub again. And after reboot, the grub menu didn't show anymore.   After searching about this problem on the net and trying to update grub again and again, I decided to delete the Ubuntu partition from live USB. And shortly after, I booted to Windows with Hiren boot and I used mbrfix. But i think it failed. Now i cant show my BIOS setup or boot from DVD or USB.   After that, the only screen i can see after booting is:  error: unknown filesystem grub rescue>


There is a big concern about loosing information inside a black hole. As far as I understand, the black hole is characterized classically by its mass, angular momentum and charge. Semi-classically, thermal radiation is added. Lot's of effort is paid to somehow restore the amount of information that crossed the horizon of a black hole, e.g. holographically on the surface of the event horizon. Why is it not allowed to simply loose the information? Is it related to the reversibility of fundamental laws of nature? If I burn the book, all the information that was stored in the special arrangement of paper and ink atoms are lost as well. Of course, the atoms still exist, but the content of the book that they were storing is lost. What is the difference in the quality of information loss between the burning and the crossing of the event horizon? Could the black hole just simply be a cosmic fire that burns everything irreversibly into thermal radiation?

I am reading Hawking's "Brief answers". He complained that black holes destroy information (and was trying to find a way to avoid this). What I don't understand: Isn't deleting information quite a normal process? Doesn't burning a written letter or deleting a hard disk accomplish the same?


I am not sure how this would work, since any solution I think of results in a mess of over complicated rules.   Thank you in advance!

Is there an injective function $f :\mathbb{R}^2\rightarrow\mathbb{R}$?  I approached this problem from the perspective of $f^{-1}$, from which I showed there exists a surjective function $f^{-1}:\mathbb{R}\rightarrow\mathbb{R}^2$. Would this imply that there exists an injective function for the inverse mapping?


I'm using bmatrix to display a simple matrix. Curiously, this does not work with a 1x11 matrix, while it does work with a 1x10 matrix:   This works just fine:  $$ \begin{bmatrix} a_1 & a_2 & a_3 & a_4 & a_5 & a_6 & a_7 & a_8 & a_9 & a_{10}  \end{bmatrix} $$   while this   $$ \begin{bmatrix} a_1 & a_2 & a_3 & a_4 & a_5 & a_6 & a_7 & a_8 & a_9 & a_{10} & a_{11} \end{bmatrix} $$   fails with   ! Extra alignment tab has been changed to \cr. <recently read> \endtemplate  l.255 ... & a_5 & a_6 & a_7 & a_8 & a_9 & a_{10} &                                                a_{11}   What does this mean, why does this happen and how can I fix it?  I'm using pdfTeX, Version 3.1415926-2.5-1.40.14 (TeX Live 2013/Debian) on Ubuntu Trusty·

I'm using bmatrix environment from the amsmath package, and I'm trying to do something like this:  \documentclass{article} \usepackage{amsmath}   \begin{document}      \begin{equation}          \begin{bmatrix}              1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & 10 & 11\\          \end{bmatrix}     \end{equation}  \end{document}   However, pdfLaTeX returns an error: "Extra alignment tab has been changed to \cr", and in the output the extra element is moved to the next row. (If I remove one element, then it works perfectly fine). I guess this means that I've hit some hard limit on the number of tab stops in a matrix. Is there a way to change this?  The elements in the matrix are short and could fit perfectly on a single row.


From Memory-Beta:     Under the Treaty of Algeron, the Federation was banned from using cloaking technology without the explicit permission of the Romulans.   What caused the signing of the treaty? I can assume from a few links on the site that such a treaty was the result of a War, but I couldn't find much more than that.  So, Why are cloaked ships banned in the federation?

The  prohibited the development or use of cloaking technology by the Federation. This treaty was a peace treaty and use of cloaking technology in one's own space couldn't disturb peace. Plus, the Romulans already had cloaking technology, so banning it was unfair for the Federation. So, why was this ban introduced?  Another thing: There were many things to ban, but why cloaking technology?


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.

Since installing the Windows 10 Fall Creators Update, I have a svchost.exe process that is constantly using about 14 % of CPU time:    This svchost.exe instance is responsible for hosting three services:    The CPU time is consumed by a thread inside that process that  cannot attribute to any of these three services:    Given that these three services are considered critical system services, it's hard to do anything about them. These services cannot be stopped or disabled by services.msc, and terminating the process triggers a bugcheck (CRITICAL_PROCESS_DIED). Disabling the Windows Defender Firewall through the settings UI does not reduce CPU usage.  I'm out of ideas. What could be causing this? How can I debug this further? Is there a workaround to stop these services?    Update: After some debugging with , we've isolated this to the Windows Defender Firewall service. Process Monitor shows that it's constantly accessing the registry:    A CSV export of a Process Monitor capture, filtered to that process, is available .  I’m still looking for a way to stop that behavior.    Update 2: Analysis with the Windows Performance Analyzer shows that most CPU time is consumed by code from rpcrt4.dll:


I want to write a bash script that will put off dropbox automatic synchronization if i'm connected to  particular wifi ssid. How can i catch this event: for example i'm working at home and sync is on, if i'm at another place (cafe, work, etc) auto sync is off.  Also I want to do some other task depending on wifi ssid.

Is it possible to auto-mount a remote FS using sshfs upon instantiating a proper VPN connection?  Allow me to explain the scenario, I'm working remotely, to do that it helps if I can mount my home dir from a server in the office. To do that I need to vpn in. So within network manager I select the relevant VPN and connect. It connects but now I have to drop to the command line and mount my home dir on several machines.  If I forget to do one machine my local dev environment isn't as efficient. I suppose I could write a quick bash script to do this but I'd rather get it running automatically when I connect.


I am not an expert on GR or gravitational waves but i have been reading about them and i wondered about where and how do these gravitational waves dump their energy? I read that the black hole collision detected by LIGO had energy equivalent to the mass of 3 solar masses in the form of gravitational waves. So, my question is where does this energy end up going?

Following the measurement of gravitational waves, many sources described them and explained they carry energy away. What I don't get is how this energy will get transfered back to anything else.  If the fabric of space-time itself is vibrating, it would seem to be in impossible for any physical object to gain this energy.    What am I missing?  How would one hypothetically get energy out of gravitational waves?  If impossible, does the universe end up with nothing but GW?


In database I have eventName: "TestEvent", startDate : ISODate("2018-11-07T13:24:03.124Z"), endDate: ISODate("2020-11-07T13:24:03.124Z")  I am setting two dates fromDate and toDate, for example fromDate:01/01/2020 toDate:01/01/2021  I want to check if the event is within this range I entered. I tried like this but the results are not correct. if ((fromDate.after(s.getStartDate()) && toDate.before(s.getEndDate())) || s.getStartDate().equals(fromDate) || s.getEndDate().equals(toDate))  Please help me, I am using utils.Date in my project. If i use : fromDate:08/08/2017 toDate: 09/09/2022  or fromDate:08/08/2019 toDate: 09/09/2019  it should return this event in this range. If i use : fromDate:01/01/2000 toDate: 01/01/2001  this event should not be in the results

Given two date ranges, what is the simplest or most efficient way to determine whether the two date ranges overlap?  As an example, suppose we have ranges denoted by DateTime variables StartDate1 to EndDate1 and StartDate2 to EndDate2.


so i studied somewhere about the type command and came to know that type command can provide the location of command used with it,more specifically the location of the executable file associated with the command, so i tried the type command with some basic commands like ps,wc,date etc and got their locations but when i used type with ls i got something different   ls is aliased to `ls --color=auto'   but i was expecting for a location.

Sometimes a command is aliased to itself. For example:  $ type ls ls is aliased to `ls -al'   How do I invoke type on the ls command itself (and not the alias)?


My Norwegian cellular provider has given me a  where I can use 50 GB of cellular data per month. After this 50 GB limit, I have unlimited data, but at very low speeds.  I traveled to Sweden with this plan, and received the following term in an SMS:     I EU/EØS bruker du av min/SMS/MMS som er inkludert i abonnementet   ditt, samt inntil 10GB av datamengden.    My translation:     Within the EU/EEC you use the SMS/MMS that is included in your   subscription as well as 10 GB of the data.   Customer care have informed me that for EU roaming data usage, the speed will be limited after 10 GB, as opposed to 50 GB for usage in Norway.  The official :     You pay exactly the same price for using these services when   travelling in the EU as you would if you were at home. In practice,   your operator simply charges or takes your roaming consumption from   the volumes in your domestic mobile tariff plan / bundle.   Is my carrier allowed to give me a separate bundle for EU usage? The EU quote makes it appear that the same bundle should apply to both.  My carrier's customer care department argues that this two month period is a "test period" and that during this "test period" they're allowed to discriminate between domestic usage and EU usage.  Are they correct? Is this allowed?   Edit: It might not matter to the answer, but it turns out that the customer care misinformed me, and that they actually do not limit the speed in the EU, instead they charge (80 NOK per GB) for EU use after the cap.

On June 15th, the EU will abolish roaming charges across all member states. However it's not entirely clear what FUP limits have been eventually negotiated:    How much data can you use on your plan before the operator can start charging you extra? Exactly how much is the operator allowed to charge for data once you exceed your FUP limit? What are the equivalent limits and charges for calls and text messages? The  mentions that "Roaming charges will no longer apply, as long as you are using your phone abroad temporarily". How long is temporarily and how much will you be charged if you stay for longer? Are there EU countries with special rules? E.g. I've read that Lithuanian operators are allowed to apply higher roaming charges to protect their market - is there a centralized page where I can learn about all the exemptions?   Links to official EU resources are highly appreciated. Kindly avoid referencing vague or unprecise statements - I assume that exact rules are already available somewhere, since the free roaming begins in 2 weeks.


A fireman is firing at a distant target and has a $10\%$ chance of hitting it. What is the number of rounds he must fire in order to have at least a $50\%$ chance of hitting the target at least once  I have no idea how to attempt this percentage type question. Can anybody please provide any suggestions on this question?  Any effort will be appreciatable.  Thanks in advance.

A shooter firing at a target has 10% chance of hitting the target in one shot. The number of times he must fire at the target to have above 50% chance of hitting the target is: How do I solve this problem? P.S.:I was thinking to apply binomial distribution to this problem,but I have no idea how to apply it here.


Our sysadmin created our mailserver years ago before he left. We recently decided to use gmail as our mail app and they required us to change the MX record to point to them on amazon route 53 app. I need to determine the old MX record we had. It's got to be somewhere on the server. I'm pretty sure it's mail.server.con. How do I retrieve this?

If is possible to find out which nameservers a domain was previously pointing too? I need to try and find where a domain was previously hosted so that I can try and gain access to an old hosted email account.   Any ideas?


Let $\def\ge{\geqslant} \def\le{\leqslant} b\in\Bbb N^{\ge2}$ be a Natural number and $p$ be a prime such that $p\nmid b-1$. For how many primes $q$ does $$p\mid b^q-1$$ hold?  I.e. for such $b$ and $p$ let $Q(b,p)=\{q\in\Bbb P \;/\; p\mid b^q-1\}$.  Is $\#Q(b,p)$   Always finite? Always infinite? Always non-empty? It depends on $b$ and $p$?     What I have:  Let $q,r\in \Bbb P$ and $r > q$, then \begin{align} p\mid b^q-1\text{ and }p\mid b^r-1 &\quad\Rightarrow\quad p\mid b^q-b^r = b^r(b^{q-r}-1)\\ &\quad\Rightarrow\quad p\mid b^{q-r}-1 \end{align}  Then due to the Euclidean algorithm it follows that $p\mid b-1$ which was excluded.  Does this mean that there is always $\#Q(b,p) \le 1$ or do I have a thinko? My intuition says that even $\#Q(b,p) = 1$, i.e. for every prime $p$ we find a sequence of ones (interpreted as number in base $b$) that is divisible by $p$. But I have no idea how to show that. Something with finite fields or so...

Attempted Proof:  Let $S = \{k: n^k-1 \equiv 0 \pmod{p}, k\in \mathbb{N}\}$. Minimal element $r$ exists by Well-Ordering. we show $r=q$.  We note, $\gcd(p,n)=1$, otherwise $p \mid n^q-1 \implies p \mid 1$.  We have:  $n \not\equiv 1 \pmod{p}\implies n^2 \not\equiv n \pmod{p}$ ; [since $p , n$ are coprime and  $p$ prime ]. Now, for any $0<j< i < r,$  $n^i \equiv n^j \pmod{p} \implies n^j(n^{i-j}-1) \equiv 0 \pmod{p} \implies (n^{i-j}-1) \equiv 0 \pmod{p} $, contradicting the minimality of $r$.   Now, we proceed to show that, all elements of $S$ are integral multiples of $r$. (Claim 1)  We have, $n^{tr} \equiv 1 \pmod{p} \implies n^{tr+l} \equiv n^l \pmod{p} $, for $0\leq l <r$. Now, for any two such $l$, say $c$ and $d$, with $d<c$ ,   $n^{tr+c} \equiv n^{tr+d} \pmod{p} \implies n^{tr+d}(n^{c-d}-1) \equiv 0 \pmod{p}$, which again contradicts our assumption that $r$ is the least element of $S$. Hence, Claim 1 is established. But, it implies that $q$ is composite (an impossibility); hence $r$ must be equal to $q$ .   Finally, by Fermat's Little Theorem, we have $n^{p-1} \equiv 1 \pmod{p}$ [ it holds, since $\gcd (p, n) =1$].   Therefore, $p-1$ must be an integral multiple of $q$, i.e. $q \mid p-1$.   PS: I am aware of the duplicates, but I want my solution checked. Thank you.


I have recorded a segment from a recent game from the new beta client replay feature. Where do those recordings get saved?  Client Beta Version: 6.22.3353521.3353110

I have seen some videos (on YouTube) of LoL games where the commentator analyze the match and he's able to move freely through the map.   Are these video made from a streaming live game or are they made by replaying something saved locally on PC?  How to save and replay a match?


How do I proceed further? (assuming what I did is correct in the first place)

I'm working on this question and it's stumping me.     Let $S_n = X_1 + \ldots + X_n$ (with $n>=1$) be a random walk with $X_1, \ldots, X_n$ be iid RV's.   $$ E(X_k)=\mu,\,{\rm Var}(X_k)=\sigma^2.  $$   Find the covariance of $S_n$ and $S_m$   Can anyone help out? I am trying to use the equation: $${\rm Cov}[S_n, S_m] = E[S_nS_m] - E[S_n]E[S_m]$$  but can't quite figure it out.


i have an XYSeries that holds Lat and Lon position of points. in some point i calculate the center point of all those positions. the code is very simple:  for(int i = 0; i < pnts.getItemCount(); i++){                 avgLon += (double)pnts.getX(i);                 avgLat += (double)pnts.getY(i);             }             cntrMass = new Vector2D(avgLon/pnts.getItemCount(), avgLat/pnts.getItemCount());   however this average calculation is not precise. when i calculate the same thing using excel sheet and the same data set there is a difference in the center point. I am using the exact number of significant digits for both calculations. the differences is of a 1e-6 magnitude, when converted to meters it gets pretty significant. any idea of how to fix this problem? any help would be appreciated.

public class doublePrecision {     public static void main(String[] args) {          double total = 0;         total += 5.6;         total += 5.8;         System.out.println(total);     } }   The above code prints:  11.399999999999   How would I get this to just print (or be able to use it as) 11.4?


I was on Minecraft the other day and I encountered a problem.  Normally on my Minecraft I click an item once and I an move it around my inventory at will.  Although when I tried it the other day, I had to click the item and drag it to move it anywhere.  It started when I loaded up the Vechs Super Hostile, Inferno Mines off of Minecraft forums. I've tried deleting Minecraft and re-downloading it, restarting Minecraft, and shutting down the computer.  Any and all help would be appreciated on the matter ASAP.  I really like this game and I don't want to have to deal with this annoying feature on adventure maps.  Thank you.

How do I fix my Minecraft inventory? I am trying to select items, but ever since the recent update, I have to click on the item and drag it to my inventory. It isn't working to fast move it using shift either. Also when I go to the crafting table it won't let me separate the items only one at a time?


We know that density of ice reduces by about 8% during freezing, this means it expands to have little higher volume. But if I fill water in a container (entire volume) which has very low coefficient of thermal expansion at 0 $^\circ$C, will the space constraints stop water from freezing?

If I have a container that is full of water and I attempt to freeze the water by freezing the container, what would happen if the container is strong enough to prevent the water expansion? Could the water be in liquid state even though it is at or below freezing point?  This is probably a daft question but its something that's been bugging me.


I know:    Quantum Mechanics (Griffiths Level, currently doing Sakurai Level) Mechanics (Newtonian+ Lagrangian/Hamiltonian but at level lower than Goldstein/Landau) Classical Electrodynamics (Griffiths + electro/magnetostatics from Jackson) Statistical Physics (Pathria)   I know very little relativity from undergrad mechanics class. Nothing about General Relativity, nothing about QFT, etc. I wish to reach string theory in a proper way without leaving any gaping holes in my education. What subjects should be studied in what order?

The question I guess is pretty clear. I am a physics undergrad wishing to pursue research in quantum gravity(string theory?). What are the subjects I should learn other than the usual compulsory undergrad courses such as quantum mechanics, and GR, etc? Things that come to my mind are QFT, lie algebras, differential geometry, algebraic geometry etc? Other than this, could you suggest any topic that are not entirely essential but interesting in mathematical physics, gauge theory etc (e.g. solitons, monopoles etc). Actually I am looking for a mini project of sorts which would give me an idea of what these fields really are. I have done some lie algebras, classical field theory and am currently studying QM.


What is the significance of the word "thin" in thin film interference. Will the phenomenon not occur when the film is thick or not of order of magnitude of wavelength of light ( thin films are of order of magnitude of light). Thick films may too produce various path differences and thus varying phase differences. Then why is the phenomenon not specified for thick films?

I had always kind of wondered why we didn't see interference in things like windows -- we were taught that the condition is that the thickness of the film/slab/medium just has to be an integral number of wavelengths, $d=m\lambda$. My logic was, if visible light has wavelengths ~400-780nm, any window pane has got to be an integral number of wavelengths (or close to integral) for some of the wavelengths in the visible.  For example, if a window is, $6mm = 6\times10^6nm$ thick, then you should see interference for wavelengths (and some range around them) 200nm, 250nm, 300nm, 400nm, 500nm, 600nm... Because 6mm is an integral number of each of those.  Obviously that would be really annoying and isn't the case. I found  (warning: PDF) source that seems to explain it and I was wondering if what they're saying is sound. On the 10th page (p171 for them), it says that the reason we don't see this interference is that no window is that smooth, it has a variance in the thickness of at least several wavelengths, so the interference effect is effectively average out among all those thicknesses, which usually gets rid of it. They do the math and show that.  Is that the reason?  If so, that leads me to two questions: Could we, if we were really careful and used something like MBE, make a glass window with that sort of accuracy, and then see interference effects in the optical range? I know that quartz crystal monitors can easily give you nanometer accuracy for evaporators and sputterers, but they also have pretty limited growth rates.  My second question is, then, do we see interference effects in glass windows with electromagnetic radiation of a comparable wavelength, like microwaves?  Thanks!


So I downloaded Skype recently and ever since, all my apps have the prompt popping up asking for permission to use things such as gallery and camera. But when I press allow, it makes me go into an endless loop of turning off overlay apps. I have no clue how to stop this and allow the permissions. The app I am trying to use my gallery on is Instagram.

Is there a way to determine which application is drawing on top of other applications?  For example, Facebook Messenger app can draw the chat bubbles on top of everything, but how do I know which app is doing this?  My problem:  I have an app which is drawing ads on top of everything and I wanna know which app is doing this. Not just to uninstall it, but to warn everyone that uses this app. (I didn't install any application recently and I already verified the recent updates.)  I tried to use the Dump View Hierarchy for UI Automator from the Android Studio, but it seems that the applications that draw on top can't be selected this way.  (Click image to enlarge)


I have a file listing 1 or more server's hostnames hostname_list that I generate using grep and awk. Now I need to execute salt commands against the hostnames. I am trying, as a test, to run test.ping to ping each server in the list. I have tried doing it as a for loop but I can't get it to work. I've tried numerous variations of: for i in hostname_list do      salt $i test.ping done

I'm looking to write a script that takes a .txt filename as an argument, reads the file line by line, and passes each line to a command. For example, it runs command --option "LINE 1", then command --option "LINE 2", etc. The output of the command is written to another file. How do I go about doing that? I don't know where to start.


Given the series $\sum^{\infty}_{n=1} \frac{n!z^n}{n^n}$ find the radius of convergence.  Well, I know that if the following Lemma holds:  Lemma  Given the series $\sum^{\infty}_{n=1} c_nz^n$ where $c_n,z \in \mathbb C$. If $\beta := lim\frac{|c_n|}{|c_{n+1}|}$ exists, then it is also agrees with the radius of convergence $\rho := \frac{1}{limsup|c_n|^{1/n}}$. That is, $\beta = \rho$  Attempt at the Solution  First I apply the lemma above:  $\frac{\frac{n!}{n^n}}{\frac{(n+1)!}{n^{n+1}}} = \frac{n}{n+1} = 1 -\frac{1}{n+1} \rightarrow 1$  If I now consider  $\limsup(\frac{n!}{n^n})^{1/n} = \limsup\frac{(n!)^{1/n}}{n} \rightarrow +\infty$   Since $\limsup(n!)^{1/n} \rightarrow +\infty$ faster than $\limsup n \rightarrow +\infty$  On the authority of the textbook I'm reading, the radius of convergence should be $e$ I'm not quite sure how one comes to that conclusion. If anyone could point me into the right direction that would be great. Thanks.

I want to find the convergence interval of the infinite series $\sum\limits_{n=0}^\infty \dfrac{n!x^n}{n^n}$. I will use the ratio test: if I call $u_n = \dfrac{n!x^n}{n^n}$, the ratio test says that, if the following is true for some values of $x$, the series will be convergent for these values of $x$: $$\lim_{n\to+\infty}\left|\frac{u_{n+1}}{u_n}\right|<1$$ So, I will first calculate the value of $\left|\dfrac{u_{n+1}}{u_n}\right|$: $$\left|\dfrac{\dfrac{(n+1)!x^{n+1}}{(n+1)^{n+1}}}{\dfrac{n!x^n}{n^n}}\right|=\dfrac{(n+1)!|x|^{n+1}}{(n+1)^{n+1}}\times\dfrac{n^n}{n!|x|^n}=\frac{(n+1)n^n|x|}{(n+1)^{n+1}}=|x|\left(\frac{n}{n+1}\right)^n$$ So, $\lim\limits_{n\to+\infty}\left|\dfrac{u_{n+1}}{u_n}\right|$ becomes: $$\lim_{n\to+\infty}\left|\frac{u_{n+1}}{u_n}\right|=\lim_{n\to+\infty}|x|\left(\frac{n}{n+1}\right)^n=|x|\lim_{n\to+\infty}\left(\frac{n}{n+1}\right)^n$$ Now I must evaluate the value of $\lim\limits_{n\to+\infty}\left(\dfrac{n}{n+1}\right)^n$. For this, let $y = \left(\dfrac{n}{n+1}\right)^n$; so, instead of calculating $\lim\limits_{n\to+\infty}y$, I will first calculate $\lim\limits_{n\to+\infty}\ln y$: $$\lim_{n\to+\infty}\ln y=\lim_{n\to+\infty}\ln \left(\dfrac{n}{n+1}\right)^n=\lim_{n\to+\infty}n\ln\left(\frac{n}{n+1}\right) =\lim_{n\to+\infty}\frac{\ln\left(\frac{n}{n+1}\right)}{\frac{1}{n}}$$ Applying L'Hôpital's rule: $$\lim_{n\to+\infty}\frac{\ln\left(\frac{n}{n+1}\right)}{\frac{1}{n}} =\lim_{n\to+\infty}\frac{\frac{1}{n(n+1)}}{-\frac{1}{n^2}} =\lim_{n\to+\infty}\left(-\frac{n}{n+1}\right)=-1$$ Now, since we know that $\lim\limits_{n\to+\infty}\ln y = -1$, we have that: $$\lim_{n\to+\infty}y=\lim_{n\to+\infty}e^{\ln y} = e^{-1} = \frac{1}{e}$$. Substituting this back into the expression $\lim\limits_{n\to+\infty}\left|\frac{u_{n+1}}{u_n}\right| = |x|\lim\limits_{n\to+\infty}\left(\frac{n}{n+1}\right)^n$, we have that the limit of $\left|\dfrac{u_{n+1}}{u_n}\right|$ as $n\to+\infty$ is: $$\lim_{n\to+\infty}\left|\frac{u_{n+1}}{u_n}\right|=\frac{|x|}{e}$$ Therefore, the series will certainly be convergent for the values of $x$ for which $\dfrac{|x|}{e}<1$, that is, $|x|<e$. So, I know that the series is convergent for $-e < x < e$, but I have to test whether the series is convergent at $x = e$ or $x = -e$. That is, I have to test whether $\sum\limits_{n=0}^{\infty} \dfrac{n!e^n}{n^n}$ and $\sum\limits_{n=0}^{\infty} \dfrac{(-1)^nn!e^n}{n^n}$ are convergent. Since these limits don't approach zero, I know they are both divergent, but I'm not sure how to find the limits, because of the factorial function. Also, I can't use integral test here, because of the factorial. Probably I should use comparison test, but I haven't found any divergent series to which to compare it. Any hints? Thank you in advance.  Edit: Using the suggestion by Ragib Zaman in the answer below, since the Taylor polynomial $P_n(x)$ of $e^x$ at $a=0$ is $$e^x = 1 + x + \dfrac{x^2}{2!} + \cdots + \dfrac{x^n}{n!}+\cdots,$$ if we substitute $n$ for $x$ we see that $e^n>\dfrac{n^n}{n!}$; therefore, $\dfrac{n!e^n}{n^n} > 1$, and, thus, we show that $\sum\limits_{n=0}^{\infty} \dfrac{n!e^n}{n^n}$ is divergent, because its term doesn't approach zero. $\sum\limits_{n=0}^{\infty} \dfrac{(-1)^nn!e^n}{n^n}$ is also divergent, because, although the absolute value of the ratio between two successive terms, $|e|\left(\frac{n}{n+1}\right)^n$, approaches 1 as $n\to\infty$, it approaches 1 from values bigger than 1; therefore, the absolute value of a term is always greater than the absolute value of the previous term.


When I run my code it is adding the value of 81 two times. Why ??? Write a program to read the contents of file Squares.txt and display the sum of all the numbers, the average of all the numbers, the largest number and the smallest number in a file named Analysis.txt. Content in Squares.txt : Number Square 3        9 5        25 1        1 7        49 9        81  #include <iostream> using namespace std ; #include <fstream>  int main() {     ifstream file ;     char arra[100];     int num1,num2,avg;     int sum=0 ;     int smallest = 9999 ;     int highest = -999 ;     int count= 0 ;     cout<<"Open file square.txt..."<<endl ;     file.open("/Users/kchumun/Documents/Xcode/Labsheet 8(3)/square2.txt") ;     if(!file){         cout<<"File cannot be opened !"<<endl ;     }else {         cout<<"File opened !"<<endl;         file.get(arra,100) ;         while(!file.eof()){             file>>num1;             file>>num2 ;             sum+=num2;             count++ ;             if(num2<smallest){                 smallest = num2 ;             }             if (num2>highest) {                 highest = num2 ;             }         }     }     file.close() ;     avg= sum / count ;     cout<<"Sum= "<<sum<<endl ;     cout<<"Average= "<<avg<<endl;     cout<<"Highest= "<<highest<<endl ;     cout<<"Smallest= "<<smallest<<endl;          ofstream File ;     cout<<"Open file Analysis "<<endl ;     if(!File){         cout<<"Error !" ;     }else{         File.open("/Users/kchumun/Documents/Xcode/Labsheet 8(3)/Analysis.txt");         File<<"Sum= "<<sum<<endl ;         File<<"Averagem= "<<avg<<endl;         File<<"Highest= "<<highest<<endl ;         File<<"Smallest= "<<smallest<<endl ;     }     File.close();     cout<<"Operation completed !";          return 0; }

The following C++ code uses a ifstream object to read integers from a text file (which has one number per line) until it hits EOF. Why does it read the integer on the last line twice? How to fix this?  Code:  #include <iostream> #include <fstream> using namespace std;  int main() {     ifstream iFile("input.txt");    // input.txt has integers, one per line      while (!iFile.eof())     {         int x;         iFile >> x;         cerr << x << endl;     }      return 0; }   input.txt:  10   20   30   Output:  10   20   30   30   Note: I've skipped all error checking code to keep the code snippet small. The above behaviour is seen on Windows (Visual C++), cygwin (gcc) and Linux (gcc).


My question differs from , for mine is specific about managing disk space on multiboot devices  From time to time, the system shows this warning message:     I have a dual-boot with Windows 10 and Ubuntu 16.04. Here's what fdisk shows:  mike@mike-thinks:~$ sudo fdisk -l [sudo] password for mike:  Disk /dev/sda: 931,5 GiB, 1000204886016 bytes, 1953525168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: dos Disk identifier: 0xc3c0f778  Device     Boot      Start        End    Sectors  Size Id Type /dev/sda1  *          2048    1026047    1024000  500M  7 HPFS/NTFS/exFAT /dev/sda2          1026048 1743806463 1742780416  831G  7 HPFS/NTFS/exFAT /dev/sda3       1743806464 1782867967   39061504 18,6G 83 Linux /dev/sda4       1782870014 1953523711  170653698 81,4G  5 Extended /dev/sda5       1782870016 1798492159   15622144  7,5G 82 Linux swap / Solaris /dev/sda6       1798494208 1953523711  155029504 73,9G 83 Linux  Partition 4 does not start on physical sector boundary.  Disk /dev/mapper/cryptswap1: 7,5 GiB, 7998013440 bytes, 15621120 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes mike@mike-thinks:~$ sudo df -h Filesystem           Size  Used Avail Use% Mounted on udev                 3,9G     0  3,9G   0% /dev tmpfs                789M   20M  770M   3% /run /dev/sda3             19G   17G  418M  98% / tmpfs                3,9G   58M  3,8G   2% /dev/shm tmpfs                5,0M  4,0K  5,0M   1% /run/lock tmpfs                3,9G     0  3,9G   0% /sys/fs/cgroup /dev/sda6             73G   63G  6,2G  92% /home tmpfs                789M   60K  789M   1% /run/user/1000 /home/mike/.Private   73G   63G  6,2G  92% /home/mike   What would you advise me to do ?

I have run into this problem two days ago. The OS warns me that root has limited disk space; however this should not be the case since I have 3 separate logical partitions for Ubuntu. Also it allows me to click the button examine, but I am not able to locate the problem that way? What can I do and what is the remedy? Inform me if further information is required.  Thanks for your assistance  Can I somehow include /usr directory in another mount point or the partition for the home folder without risking losing my data?  The culprit seems to be the /usr directory. The problem occurred after a full TexLive LaTeX installation. The output of lsblk is as follows:


The fonts from Facebook in Chrome (only Chrome) are not displayed correctly. This happens on only two computers on my home network.  All computers have Chrome 37.0.2062.103 m.  I have Windows 8 and the fonts are ok   The other two computers have Windows 7 and they look like this   What I have done so far:   read the other questions :) uninstall chrome and deleted all the files related to chrome reinstalled chrome Control Panel -> Fonts -> Font Settings -> Restore Default Font Settings

Today Google Chrome 37  and well... the fonts looking ugly. It looks unsharp like on most .NET programs. Is there a way to disable DirectWrite and get back to Chrome <= 36 font rendering?  EDIT: To show you what I mean, I took two screenshots of this website:     DirectWrite On:            DirectWrite Off:         As you can see, with DirectWrite activated the vertical lines are sometimes unsharp. Without DirectWrite the vertical lines are mostly sharp and exact on the pixels of the screen.


Why there is a 'the' before earlier?  "... demonstrate that the earlier someone learns an additional language the more likely they are to master it."

What is the function of "the" in these kinds of phrases? It cannot be the definite article.   Can someone analyze this? It's common and definitely standard but seems to elude any grammatical explanation.


I'm new to Blender, and I'm doing a very simple render using Cycles.  As you can see in the image, I'm getting horrible faceting in the shadows on the sphere.  Does anyone know how to fix this? Thanks!

When I increase the point light radius, it ends up creating artifacts on the textures for seemingly no reason.  Even though I I have High Quality Shadows (High bit-depth and cube map resolution).  I want to create a smooth texture just like the corner of the photo, but for some reason it ends up creating these squares with what looks like many "vertices".


The sys.getsizeof() function returns the size of an object in memory, in bytes. As this function may return inaccurate results for third-party , how do I determine how much memory a BioPython object is using?  I loaded a 286MB file using  code (modified):  from Bio import SeqIO handle = open("example.gb", "rU") records = list(SeqIO.parse(handle, "genbank")) handle.close()   and sys.getsizeof(records) indicates that it is using 268KB.

How would you go about finding out how much memory is being used by an object? I know it is possible to find out how much is used by a block of code, but not by an instantiated object (anytime during its life), which is what I want.


So my question is how do I fix an object that was made by joining two separate objects together. Specifically what I want to fix is the color issue, I need it to be one color and without any distortions.(greyish black parts) Would be glad if anyone can provide feed some back.

What's happening is that I have tried to flip the normals, inside and out, but there are always faces which have to be flipped!  Normals recalculated   Inside View    If I flip them again, all faces get flipped and end up horrible and, not working at all. So how can I make all of the faces flip to the right direction?


I'm currently putting together my CV to apply for postdoc positions.  After each paper in my publication list I want to put a short paragraph with an overview of the paper and exactly how I contributed to it.  I have been unable to figure out a way to do this cleanly and I'm currently using this workaround in BibDesk:  I click on the relevant publication and in the 'Year' field (which is usually the last field) I put the following:  2013 \newline \newline \begin{small} "text describing paper" \end{small}   This is quite a dirty workaround however as I am left with an additional full stop (  .) after the descriptive paragraph.  Also if the DOI field is used, it comes after the paragraph.  Does anyone have any suggestions as to how to better annotate references in a publications list?  I feel these descriptive paragraphs are critical for someone assessing my publication record.

I'm trying to create an annotated bibliography. Here's my .tex document:  \documentclass[12pt]{article} \title{Annotated Bibliography}  \begin{document}  \nocite{*}  \bibliography{annotatedbib}  \end{document}   And here is the associated .bib document:  @Misc{hacker,     AUTHOR = `{Andrew Hacker'},     TITLE = {Is Algebra Necessary?},     HOWPUBLISHED = {New York Times},     MONTH = {July 31},     YEAR = {2012},     ANNOTE = {This article was published in the New York Times.}, }   No matter into which format I compile my .tex document, the annotation will not show up! Is there something that I'm missing?


I would like to ask where to ask a question like this:     I'm just curious if there are any known plans about what happens when the LLVM version numbers eventually catch up to Apple's ridiculous version numbers.  It's close if not has already happened.   Does such a question belong anywhere on the Stack Exchange network, or should I reach out to the mailing lists?

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


I don't need ImageMagick in the Dash but need to keep it as a installed program because many other programs depend on it.  Question:  Can I somehow hide the two icons or do I have to delete them?  Screenshot:

I would like to hide all items that I don't need from appearing in App Lens.  For example: XTerm, File Roller and the Home Folder.  Is this possible?


For years I've had it drilled in to me:      Never ever shrink a database file.   I understand why of course, and I never do, mainly because I never need to.  Now though, I have a database with an .mdf file that is 800GB. It was a system designed to collect data over a certain amount of time, with no retention period.  A retention period of 90 days was recently placed on this data, and as such the developer has cleared about 3 years worth of data from the tables. Data and Indexes now total roughly 70GB, so now I have an .mdf file which is grossly over-sized.  I want to shrink it to reclaim some of that valuable disk space.  I'm planning to perform a shrink prior to rebuilding indexes and updating statistics (i.e the weekly maint. plan)  I'm not breaking any DBA laws here am I? I assume this is an acceptable scenario in which to perform a SHRINK as it is a true one off?  Thanks

I have a database, that due to some silly code issues has grown hugely. It is now sitting at 24GB, most of it is very unnecessary logging information (system generated debug information).  My server lives on a cloud hosted server. I am now sitting with 2 issues because of the file size:   I pay for storage. I am happy to pay for my core business, but paying for silly data seems....silly My backups are now huge also. I do nightly full backups, and then ship them off to an FTP server. This process is taking longer and longer.   Given my issues, is shrinking so bad? I will rebuild all my indexes. I did a dry run, and brought my database down to 6GB.  This guy (who I have always trusted as my SQL guru), says it's bad....mkay


I have started it like this If $p>2$, then $p= 2k+1$ , $p^2= 4k^2 +4k+1$, $p^2 -1 = 4k(k+1)$ , But I can't get how to make it divisible by $8$.

Let $p>3$ be a prime. Prove that $24 \mid p^2-1$.   I know this is very basic and old hat to many, but I love this question and I am interested in seeing whether there are any proofs beyond the two I already know.


Since lines that meet at some point have an angle. And if parallel lines meet at infinity, then that what is the angle of two parallel lines that meet at infinity?

My teacher told me that two parallel lines have a point of intersection, it is called Point at infinity. But I I can't understand how it can be true or how was it proved, can someone explain this to me?  Thank you.


Is it known how many secret hats exist in this winter bash? What about last year?  Also, are hats being added during the event? Should the Stack Exchange team come up with new ideas?

So far, I've unlocked one of the secret hats. I'm wondering what other secret hats are out there and how to earn them?


I'm 16 and I've learned to develop iOS apps recently.  I've finished my first app yesterday and I want to upload it to the App Store.  I've tried to register with my name and my father's credit card and I got the verification code from Apple. But when I'm trying to sign in to my account I get this error message:     We are unable to activate your Apple Developer Program membership.   We have received your purchase information and will email you shortly to verify additional details.   Additionally, I'm trying to reach Apple Developer Support for over an hour but they don't answer the phone.  Any idea what can I do with that?

When I registered to be an Apple Developer, I inadvertently did so without realizing the requirement to be 18 years of age (I was 17 and 6 months away from being 18 at the time). I did not take out any sort of paid membership at the time, however.  I am now 20, will this cause me any problems now or is it nothing I need to worry about?


My setup is fresh Ubuntu 16.04 server installation with Apache 2.4.18 and Openssl 1.0.2g. I have made ssl configs to /etc/apache2/mods-available/ssl.conf and checked that there are no same configs in vhost -files etc. Still no matter what I do I cant get no change on ssllabs.com raport. I tried even comment all SSLProtocol and SSLciphersuite lines but still no change. Yes I have restarted the server after the changes.   What am I missing?

I generated self-signed certificate with latest Ubuntu OS and OpenSSL in it. Certificate has RSA 4096 and SHA512...but it uses SSLv3 and from mozilla I can not access the web page because Mozilla does not support SSLv3 anymore. How can I generate cert. that uses TLS?


Prove that if $f$ is analytic in a region symmetric with respect to the real axis and if $f$ is real for real $z$, then $f (z) = \overline{ f (\bar z)}.$ My attempt : If i take constant function $f(z)=1$ , then obviously it will satisfied $f (z) = \overline{ f (\bar z)} $ since $\bar1=1$ If $z=x \in \mathbb{R}$ then $f(x) =\sum_{n=0}^{\infty} a_nx_n $ Then $\overline{f(x)} =\overline {\sum_{n=0}^{\infty} a_nx_n}=\sum_{n=0}^{\infty}\bar a_n x^n$

Let $U\subset \mathbb{C}$ be a nonempty connected open set such that for every $z\in U$, $\overline z\in U$.  Let $f$ be analytic on $U$. Suppose $f(x)\in\mathbb R$ for every $x\in U\cap\mathbb R$. Prove that $f(\overline{z})=\overline{f(z)}$ for any $z \in U$.    By definition, I know that $f$ analytic on $U$ means that for every $z_0 \in U$, there exists $r>0$ and a sequence of complex numbers $\left(a_n\right)_{n=0}^\infty$ such that $f(z)=\sum_{n=0}^\infty a_n\left(z-z_0\right)^n$ on the disc $D(z_0,r)\subseteq U$. I see that $f$ takes points without imaginary components to other points without imaginary components. But I don't see how this implies a symmetry that $f(\overline{z})=\overline{f(z)}$ for $z \in \mathbb C \setminus \mathbb R$. It seems like a very strong conclusion and I'm not sure how I would prove it.  I have also shown in the preceding question that $U\cap\mathbb R$ contains an open interval, however I am not sure if that detail is meant to be helpful to this question.


I'm interested in evaluating the integral of   $$ \int_0^\infty \frac{\ln(x)}{e^x+1}\ $$  TLDR: How do you evaluate $ \eta'(1) $?  I found and adapted this integral from , unfortunately, they didn't fully evaluate the integral and I'm interested in the result.  This question is similar to , but my question goes more in-depth on the way that I tried to evaluate this integral.  This was solved by @J.G. in the answers, and by @Zacky in the comments.  I'll run through what I did and what the video did to evaluate the integral  $$ I =\int_0^\infty \frac{\ln(x)}{e^x+1}$$  Multiplying by $ \frac{e^{-x}}{e^{-x}}\ $ results in  $$ = \int_0^\infty\frac{e^{-x}\ln(x)}{e^{-x}+1} $$  Expanding the denominator into a geometric sum results in  $$ = \int_0^\infty\ e^{-x}\ln(x)\sum_{k\ge0}{-e^{-x^k}} $$  Interchanging our signs of integration of summation and simplifying results in  $$ \sum_{k \ge 0}(-1)^k \int_0^\infty\ e^{-x(k+1)}\ln(x) $$  Substituting $ x(k+1) = t $ and $ dx = \frac{dt}{k+1} $ results in  $$ \sum_{k \ge 0} (-1)^k \int_0^\infty e^{-t}\ln(\frac t{k+1})\frac{dt}{k+1} $$  Expanded and simplified you get  $$ \sum_{k \ge 0} \frac{(-1)^k}{k+1} (\int_0^\infty \ln(t)e^{-t}dt - \ln(k+1)\int_0^\infty e^{-t}dt) $$  Once again simplified we can see that our first integral is the $ \mathcal L\{\ln(t)\} $ at $s = 1$ and our second integral is $\Gamma(1)$ in total this results in.  Where $ \mathcal L $ is the Laplace transform and $\Gamma$ is the Gamma function.  $$ \sum_{k \ge 0} \frac{(-1)^k}{k+1}(\mathcal L\{\ln(t)\}-\ln(k+1)\Gamma(1)) $$  This then simplifies to  $$ \sum_{k \ge 0} \frac{(-1)^k}{k+1}(-\gamma-\ln(k+1)) $$  With $ \gamma $ being the euler-mascheroni constant  Increasing our lower bound on our summation we get  $$ \sum_{k \ge 1} \frac{(-1)^{k-1}}k(-\gamma-\ln(k)) $$  Realizing that the Dirichlet Eta function is defined as  $$ \eta(s) = \sum_{k \ge 1} \frac{(-1)^{k-1}}{k^s} $$  We can then see that our equation is   $$ \eta(1)(-\gamma-\ln(k)) $$  Knowing that $ \eta(1) = \ln(2) $ we can then distribute our eta to get  $$ -\gamma\ln(2)-\ln(k)\eta(1) $$  Which is   $$ -\gamma\ln(2) - \sum_{k \ge 1} \frac{(-1)^{k-1}}k\ln(k) $$  Taking the derivative of the eta function we can see that this is  $$ -\gamma\ln(2)+\eta'(1) $$  According to  $ \eta'(1) $ is equal to $ \gamma\ln(2)-\frac{\ln(2)^2}2$  Meaning that our integral $I$ will evaluate to  $$ I = -\frac{\ln(2)^2}2$$  But how can we evaluate $ \eta'(1) $ without encountering the pole at $s = 1$ of the Zeta function?  Are there any other interesting ways to evaluate this integral not using the eta function?  Thank you for your time and patience!

$$ \int_0^{\infty } \frac{\log (x)}{e^x+1} \, dx = -\frac{1}{2} \log ^2(2) $$  Anyone an idea on how to prove this?


I read this in the 1990s, I think as a paperback. Aliens have taken over Earth. The main character lives with the aliens and does not consider himself as human, but as an oddly shaped alien. Somehow, he winds up in contact with some of the humans who are in rebellion, including an awkward sex scene where I remember the female kept referring to his "joystick". He learns how the humans are kept as livestock, involving what is essentially a pithing operation to ensure that they don't have higher brain function. For some reason, I want to say that either he or the aliens liken the livestock humans to pigs. The only other detail I remember is it being established that ruins of the major cities such as New York are now underwater... he's with the rebel female at the time, but I'm not certain if they're still in the alien ship, or if they're in their own ship.  I know that this is not I, Weapon which has a similar concept of humans raised as livestock, but a wholly different plotline.

I'm looking for a sci-fi novel I read in the early 2000s at a local library. Judging by how often they actually got new books, it has to be between the 50s and 80s - if I had to guess, late 70s? The most prominent things I remember:  Canine aliens were the main alien species There was one human boy that was like their pet. Outside of him, there may have been one other human that was seen. The aliens put a large amount of importance on poetry shaped like its subject. The boy wrote a poem about either the Moon or Earth that was round in shape. One of the aliens was named Oberon, and the human frequently called him Obie.


I have already searched everywhere but those threads are about making rope-like objects.  I am trying to animate start and end values of a curve's geometry. But I want it to twist midway. I am trying  to rotate it's segment on Y axis as in the image but it is not working.    Here on the left is what I want to achieve and right is what I have. I tried rotating the segment/vertex on Y axis but its not working.

I have attached an image as an example below. I want to twist a rectangle. Do I have to convert that rectangle into a curve or into mesh and then twist it with ctrl+T?   Please explain with an example.


I am trying to delete a folder on my D:\ drive. I tried tried everything up till loading myself as the system account in a CMD see below.  D:\>takeown /F torrent ERROR: Access is denied. D:\>whoami nt authority\system D:\>   Unedited from my CMD Window.

I have got this file that I can't delete. It happened after a system crash, so the CHKDSK kicked in upon next reboot. After that, I can't delete the file.  THis is on Windows Home Server, and the file is one of those hidden Thumbs.db, and my WHS reports a "File conflict" on the file, the reason: Access Denied"  What I have tried so far, running as an Administrator: Delete: Access Denied TakeOwn.exe : Access Denied Attrib.exe -s -h : Access Denied cacls.exe : Access Denied   (even whe trying to display the current owner) Rename: File not found (its hidden) Re-boot in to safe mode and tried the above: Access Denied Running the above commands as Local System: Access Denied   Tizer Unlocker: Fail (Doesn't find anything locking the file) File Assasin: Crashes ("FindRemoteFileHandles returned NULL value.")  I have used the CHKDSK /f again, rebooted since some suggestions is that the file has been corrupted, but that didn't change anything. Any suggestions ?  Update: In a total separate scenario, I experienced a similar situation; Access Denied when trying to take ownership of a file. It turned out that the file was owned by TrustedInstaler, which is not possible to override just by being an Administrator. In this case, one can use psexec /ids cmd to elevate yourself to System and then TakeOwn.exe /a


I use TikZ to create drawings. They are composed of text, arrows, and svg-icons (e.g. coming from the ). These icons (svg files) are mono-color only (i.e. black & transparent). What I'm used to do is to download them, change their color using Inkscape (i.e. black -> blue), and then import them as a node:   \node (my-picture) at (13,17) {\includegraphics[width=210pt]{myPicture.svg}};   However, if I want to change one color (e.g. let the main color of my document be green, and not blue anymore), I need to manually edit each .svg file.  Question: Would it be possible to include the raw .svg-file and specify its color as a TikZ option? E.g. \node [svgcolor=orange] (my-picture) at (13,17) {\includegraphics[width=210pt]{myPicture.svg}};

I have a graphic in PDF format (originally converted from an SVG) that is monochromatic (black on white). Is it possible using TikZ or PSTricks but not (Illustrator or Inkscape) to include this image in a different color?  Example:    While it lasts (there seems to be no long term way to host a pdf), you can .  Edit: Simple was perhaps a bit of a misnomer - the pdfs are cropped and monochromatic, but to intricate to redraw on my own. The above example is a character from a font (which I can recolor), but it gives a good example of what shapes I am talking about.


I googled, but didn't seem to be anything out there.    I need to design a set of icons that will be functional at really tiny size (16px x 16px).  I realized that a lot of the icons I designed starts out looking nice, but will look unrecognizable when I resize it at 16px x 16px.    I'm just wondering if anyone has any tips in the dos and don'ts for designing tiny things?  To make it icons look good and functional at 16 x 16.

I'm busy on a WordPress site and have come to the stage to add the finishing touch, being the favicon. I'm primarily a developer so graphics and icons aren't my strongest point.   What are the best practices when creating a favicon (in terms of sizes etc, I already have the design)? I'd like to accommodate for every possible device, be it mobile, tablets, retina displays etc. Also I don't want it ending up blurry so I need to know what pixel density to use and everything.  If there are some Mac apps or online tools that will do this for you (and do it properly) that would be great as well. Otherwise I know how to find my way around Illustrator and Photoshop.


At the back of the book which contains this problem, a hint is given to consider $$S_n\cdot2^{k-1}\cdot3\cdot5\cdot9\cdot\ldots$$ where $2^k \le n < 2^{k+1}$.  I don't know how this helps? I know that every positive integer can be written as a sum of powers of 2, but not sure if this is relevant.

If $n>1$ is an integer, then $\sum \limits_{k=1}^n \frac1k$ is not an integer.  If you know , then you know there must be a prime $p$ between $n/2$ and $n$, so $\frac 1p$ appears in the sum, but $\frac{1}{2p}$ does not. Aside from $\frac 1p$, every other term $\frac 1k$ has $k$ divisible only by primes smaller than $p$. We can combine all those terms to get $\sum_{k=1}^n\frac 1k = \frac 1p + \frac ab$, where $b$ is not divisible by $p$. If this were an integer, then (multiplying by $b$) $\frac bp +a$ would also be an integer, which it isn't since $b$ isn't divisible by $p$.  Does anybody know an elementary proof of this which doesn't rely on Bertrand's Postulate? For a while, I was convinced I'd seen one, but now I'm starting to suspect whatever argument I saw was wrong.


Since Lord Voldemort has become less and less human, does that exclude him from the effects of a Dementor which feeds on human emotions?   I'm not asking about what would happen if a Dementor kissed Voldemort and sucked his soul out. Dementors feed off the happy emotions of people until they're left with their worst memories. Seeing that Voldemort doesn't actually feel any happy emotions as such, will he feel the same despair and fear if he got near a Dementor? Is there anything left in Voldemort which the Dementors could feed off?

Pursuant to  (Could the Dementors' Kiss Destroy a Living Horcrux?), I have a follow-up question. Based on what we know about the Demetors' Kiss, the soul, and Horcruxes from canon, what effect would the Dementors’ Kiss have upon Voldemort prior to all his Horcruxes being destroyed? If Voldemort had received the Dementors’ Kiss and had his soul sucked out, would his Horcruxes keep his mind intact? Or would he be turned into a shell of a person, like anyone else who received the Kiss, existing forever in a vegetative state, kept physically alive by his Horcruxes? Would natural death ever occur?


When do I have to use "will + verb" after that clause?     He said the project will be carried out.   vs     He said the project would be carried out.   According to the tense agreement, I think the first sentence is right.   Is there any slight difference?

I recently got confused with the following choices while talking to a friend after class:  I sent her an email that I wouldn't come to the class. I sent her an email that I wouldn't be coming to the class. I sent her an email that I won't be coming to the class. I sent her an email that I won't come to the class.  Can we use the third and fourth sentence by any chance or is it completely ungrammatical? Some websites including the NYTimes have instances where both the past and future are mixed in their reports.


New visitors to Stack Exchange can post questions or answers as a guest.  The site asks them to specify their name and their email address.  If they're lazy and they leave the "name" field blank, the site will auto-generate a display name for them, such as "user9276583".  Email verification is a separate step.  They must take additional actions in order to get an verification email sent to them.  Then they must open the email and click the link.  If a guest is so lazy that they didn't specify a display name, I think it's reasonable for me to fear that they might also have been so lazy that they never completed email verification.  Still, I might be tempted to ask in a comment in order to seek clarification of their tech-support question.  In practice, if a user is 100% brand-new to the Stack Exchange network, and if they have an auto-generated display name, what are the chances that they'll ever be back again to respond to my comment?

I often see users who appear as user12345 or something similar. I personally dislike this for a few reasons:    I'd prefer to know who I'm dealing with I think the quality of questioning is generally better from users who have an identity Somehow it seems like cheating... disrespectful in some intangible way.. here we all are helping each other for free, and what? You can't even be bothered to show your face?   I've read the question   and there the conclusion seems to be that we don't mind whether the identity is real or adopted.   Fair enough. My problem is with people who can't even be bothered to have an identity at all. (I understand that in some cultures, it might be seen as problematic to make community contributions on your boss's time, even if there's a net gain. Lots of the user12345 folks seem to be asking for work-related answers: even full-blown solutions.)  Coming back to my first point about wanting to know who I'm dealing with; I actually can't tell the numbered users apart. Those numbers just don't stick in the brain, so it becomes like trying to interact with the Borg. Even if people have reasons to conceal their 'passport' identity, why can't they at least be encouraged to put some minimal imagination into making up a fake?   Stack overflow has successfully gamified all sorts of things, so isn't there a way to lean on people (ever so gently) to put a little bit of effort into dumping the auto-generated name. Nag them every 5 logins? Whatever.


I have 2 HD's; 40 GB,Ch0 master with Win XP; 160 GB,Ch0 slave with Ubuntu 12.04. I used Parted Magic to repartition the 160 GB drive and I changed the jumpers to reverse the master/slave position. Now I have Win XP on the 40 GB slave drive and an empty 160 GB HD master. I partitioned the 160 GB HD as 1 GB boot; 78 GB root; 62 GB Home and 8+ GB Linux-Swap.  I used Parted Magic and Boot Repair Disk to install the MBR and Grub2; however, in searching the drive I can't find them. Atempts to install Ubuntu 14.04 using a DVD+R, I consistently get the message "missing operating system - operating system load error". Does anyone have an idea why the Ubuntu 14.04.1-i386-iso won't load?  I followed the suggestions of Virusboy and gyropyge by deleting the partitions. I also disconnected the Windows XP drive as suggested by gyropyge. The Seagate Barracuda 160GB drive was designated as unallocated. I then attempted to install Ubuntu 14.04.1 from a DVD iso I downloaded from the Ubuntu website. I set all 3 options in the BIOS to boot from CDROM. Upon restarting, after the BIOS processed, I get "missing operating system" which repeats until I shut down. I then used Parted Magic, changed the drive from "unallocated" to one large formatted partition. I got the same result: "missing operating system".

I would like to see a full how-to guide on how to install Ubuntu.


I set $\lim_{x \to \infty} x^{1/x}=L$  What I tried is this:  $$\lim_{x \to \infty} \frac 1x \ln x=\ln L$$  $$\lim_{x \to \infty} \ln e^{\large \ln \frac 1x} \ln x=\ln L$$  We substitute in $e=\lim_{x \to \infty} (1+\frac 1x)^x$   $$\lim_{x \to \infty} \ln (1+\frac 1x) \ln x=\ln L$$  $$L= \lim_{x \to \infty} (1+\frac 1x)^{\ln x}$$  This looks a lot like the definition of $e$ and from here I think I could make an argument that $L=1$ because $\ln x$ increases slower than $ax$ for any $a$ after a certain point, but I would like to have a proof that is more direct. How should I proceed from here? Thanks.  P.S. No L'hopital's rule please

I've spent the better part of this day trying to show from first principles that this sequence tends to 1. Could anyone give me an idea of how I can approach this problem?  $$ \lim_{n \to +\infty} n^{\frac{1}{n}} $$


I'm extremely new to blender and need to know, before I get going, if it is possible to use my animation on websites. I develop websites and am looking for an animation software to make my websites even better, so before I start putting a lot of time into learning blender, I need to make sure it is possible to use it on my website.

If I make a scene and then render it with BR or Cycles, am I allowed to use that image in a commercial project? Do I need to include any copyright notice or license?


I am trying to create a custom service and call it from a controller that is being used on a route. I use simple code, so I think I am missing something  The membership service:    Controller:   services file:   routing file:   The error I get:     RuntimeException: Controller   "Drupal\hsbxl_members\Controller\Test::test()" requires that you   provide a value for the "$container" argument (because there is no   default value or because there is a non optional argument after this   one). in Drupal\Core\Controller\ControllerResolver->doGetArguments()   (line 165 of   /var/www/drupalvm/web/core/lib/Drupal/Core/Controller/ControllerResolver.php).   So it seems the ContainerInterface $container is missing when the controller is being initiated. But how do i do this? Confused.  Cheers! Tom

I am using the following line in a controller class.      \Drupal::moduleHandler()->alter('mymodule_myfunction', $plugin_items);   Pareview.sh is giving me this error message.     \Drupal calls should be avoided in classes, use dependency injection instead.   How should I accomplish this? Do I need to create a constructor, create a method, or a service? If so, what code should the service need? I found an example on  for a case where a service already exists.


Trying to create a function that returns a table. I want to pass the table's name as parameter. This is what I tried: create or alter function cust (@T NVARCHAR(250) )  returns table  return (select * from @T)  But getting an error. What can be done?

I am attempting to create a stored procedure where a table name is passed as a parameter, as well as updating contents of the table. Here is my code I have so far.  SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO ALTER PROCEDURE TableSelect     @TableName varchar(100) AS BEGIN     SET NOCOUNT ON;      Declare @String varchar(100)     SELECT @String = 'Update '     SELECT @String = @String + @TableName     SELECT @String = @String + 'Set Internet = 1'      EXEC (@String)  END GO   When I attempt to execute by this command:  EXEC TableSelect 'Waterford';   I get the error:  Msg 102, Lvevl 15, State 1, Line 1 Incorrect syntax near 'Internet'.   Any help would be great. FYI, the column Internet, is just a bit so 0/1 or False/True. Thanks


I have a templatized class definition in test.hpp  /////////////////////////////////////////////// class point1 { public: int z0;  point1(): z0(1) {} }; /////////////////////////////////////////////// class point2 { public: int z1;  point2(): z1(2) {} }; ///////////////////////////////////////////////  template <class T> class line {  public: T p1;  void printPoint(void); };   and in implementation file test.cpp I am trying to specialize the printPoint function of class line   ///////////////////////////////////////////////  template<>  void line<point1>::printPoint(void)  { cout<<p1.z0<<endl;  }   template <class T>  void line<T>::printPoint(void)  { cout<<p1.z1<<endl;  }  //////////////////////////////////////   and main function is in testmain.cpp   int main()  { line<point1> r1; line<point2> r2;  r1.printPoint(); r2.printPoint();   int abc; cin>>abc; return 0;  }   But linker throwing error that printPoint function is multiply defined. Is it a correct way of member function specialization of a class if not than how to specialize member function of a templatized class? Please help.

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


We are using 2 AppServer with an Idle Workload of 10 Apache Workers and and 5 Hits per Second.  These Servers got 12 CPUs and 8GB of RAM. Monitoring is accessed by Zabbix. My question about this is - are these Servers way to much for the traffic we gernerate? And equals max_connections (we have 500 set)with active workers?  We have the monitoring, but do not know what the max really is and the hoster will not answer us.  Thanks in advance.

This is a  about  Related:      I have a question regarding capacity planning. Can the Server Fault community please help with the following:   What kind of server do I need to handle some number of users? How many users can a server with some specifications handle? Will some server configuration be fast enough for my use case? I'm building a social networking site: what kind of hardware do I need? How much bandwidth do I need for some project? How much bandwidth will some number of users use in some application?


Looking the graphs that report the number of deaths by coronavirus in worldometer, I have noticed that for many countries there is a clear oscillation with a one week period. See for example the graph for the UK and the US:   Why do you think this is happening? It seems to me that for some reason, the number of deaths is under-reported during the weekends.

The covid19 death data for US shows strong periodic trends. It does not make sense to me that people die periodically.   What could be the reason to having such data? I thought it might be the reporting artifacts, for example, people always update data at Monday, but the period seems to be 3-4 days.


I just recently finished a Neutral route because I was trying to do genocide. I killed every monster I came across. When I found out you need to HUNT down every single monster, I tried to, and was doing pretty good until I came to snowdin. There's 3 monsters left, and I can't find a single one. I tried to google it, but all the answers that came up were for the computer. I am on a switch. Can you please help?

I was doing a genocide run and I got stuck because I don’t know where to find the monsters I need to kill to progress


I have a pivot box that I access only through SSH.  It has a small hard disk and I will never use GUI apps on it so I want to purge those.  Ubuntu 16.04.  Please recommend a safe way to do this.    EDIT:  Some people think that this is a duplicate of .  Reading them both makes it clear that it is not.  That one is about Ubuntu 10.04, not 16.04.  And the answer there doesn't work on Ubuntu 16.04 but anyway why would it?

Cross post from   I have a laptop I'm running as a file server, which is running Ubuntu 10.04 Desktop. Now that summer heat is here, and because I love the environment, I'm look for all sorts of ways to reduce the laptop's power/memory/heat footprint.  One part I never touch any more is the GUI as the lids always closed.  I thought perhaps simply removing GDM from all run-levels my achieve this, so I did so using sysv-rc-conf. However this didn't make any difference and upon reboot the lovely Ubuntu boot screen and graphical login prompt appeared.  Please help!  Additionally, perhaps this is a silly question, I want to make sure that the monitor is off at all times the lid is closed, which it is already set to do when the GUI is running, can/do I need to configure this separately for non-GUI environments? (Seems to be doing this fine)  Thanks :D  EDIT: Ok maybe I'm using sysv-rc-conf wrong and it needed 2 reboots to apply the settings or something? As rebooting it a second time since removing GDM from all run levels I got a command prompt.  However I didn't watch it reboot and was a little confused by this, so I rebooted what I believe to be a 3rd time, and now it's booted to a black screen with a solitary white underline in the top-left, no other text. No amount of keyboard mashing in order to change run levels is having any effect, however I am able to access it via SSH and the SMB shares, so I suppose it's doing almost what I want. The lack of a CLI on the screen itself is still concerning however.


My wife accidentally smashed the screen on her Sony Xperia Z3 and the touch screen is not useable. There are colors and lines but nothing else. All of the ports on the device work just fine. However, I cannot access the phone's files with my PC because USB connection settings are currently set to charge the phone. I need to do the Data Transfer setting but am unable because of the broken touch screen. I talked to Sony support and they were no help whatsoever.  Can someone please tell me if there is a workaround? I am a tech so I will understand what you are saying even if it is complicated. Thanks, Mark

I just broke the screen of my (unrooted) Galaxy S.  How do I get back my SMS and contacts?   PS: I tried Kies but it won't detect my phone for some reason. (Kies works fine with another Galaxy I possess but not this one)


I have the following Enum:  public enum Food { APPLE, BREAD, PIE, STEAK; }   I want to store the user's chosen food like so Food food = scanner.next() (obviously this is incorrect). What would be a good way to do it?

Say I have an enum which is just public enum Blah {     A, B, C, D }  and I would like to find the enum value of a string, for example "A" which would be Blah.A. How would it be possible to do this? Is the  the method I need? If so, how would I use this?


Why walk to class when you can simply apparate?  Why run from a pursuant instead of just apparate somewhere else?

It is mentioned many times that people cannot Apparate or Disappate within Hogwarts. That is all well and good. Except in Harry's 6th year, when all the 6th years are learning how to Apparate.   The Apparation Instructor says     Dumbledore has removed the restriction on Apparation within the Great Hall.    This means the Headmaster has the ability to remove the enchantment at will. So why the restriction?