I'm trying to install a video driver on my Ubuntu 16.04 system, and the instructions caution me to set runlevel to prevent the X server from starting. Using what was posted in  I've had problems doing that, so as a workaround I decided to boot to recovery mode and use the "root shell prompt" option.  This worked fine until I tried to run the run file and fouond that I forgot to set the executable bit.  I entered a cdmod command. It came back with the message "readonly file system."  So I have to return to the X server to start a terminal window and set the executable bit.  Except that once I do, I won't be able to use the run file anyway because it has to write files to do its job.  So recovery mode gives me root access but makes the file system read only? What? Is this some kind of stupid joke?

I deleted two unused user accounts. Now I am unable to login even into my own account. I rebooted in recovery mode in the root shell and tried to restore the back-up of /etc/passwd. However, the filesystem is read-only!  I can only access root shell via recovery.  Can you help me?


A feature that has been requested several times, which has never been attended to, and with no real arguments other than the amount of work. So my question is:  why instead of working on any kind of theme related we get this awful buggy "time travel" bad joke theme that no one requested?

Each Stack Exchange site should provide users the option of using a dark mode design/theme.  Why is this feature missing?  The major IDEs are already a letdown regarding dark color schemes.


OK, I got it. There has been plenty of  asking dumb good practice questions. And yes, most of the good practice questions lead to opinion-based answers.  But then, good practices a essential for learning and mastering programming languages. And good practice question may even be .  StackExchange's format is great to gather opinions from experienced users. So if I still have good practice or a opinion-based questions (e.g. I hesitate between two ways of programming/structuring my code and I would like experienced users to argument over one or another), where can I ask them?  Couldn't there be a sub-site of StackExchange dedicated to such kind of questions?  I know my question is pretty opinion-oriented. But Meta is the one place where opinion-oriented questions are asked. Why not somewhere else?

I'm on SO pretty much every day researching something to do with programming, and over the last month or two, I find I'm growing frustrated and a little disgusted at how many interesting questions have been closed as "not a good fit" or "too subjective".  I think there is a confusion between "subjective" and "calls for judgement". To me one of the most valuable things about SO is the tremendous breadth and depth of experience of the members, and experience translates into smart decisions and advice, and that advice cannot always be asked for, or expressed in terms of, bald facts and data.  It's going to be 'subjective'.  I don't think SO should be Wikipedia. I think that if I could ask a question to a group of skilled programmers sitting around a table at lunch, and get interesting, valuable answers, then I don't care whether the question or the answers are 'subjective', I think that question should equally well be fair game for Stack Overflow.  I would like to see a mechanism whereby people who vote to close a question lose reputation when somebody expresses interest in that question or its responses.  How can I, or can I, influence this aspect of SO?


Okay, so I had Ubuntu 20.04 installed alongside with Windows 10 on dual boot grub. Then I decoy to get rid of Ubuntu so from windows I deleted the Ubuntu partition and restarted my computer hoping I’d load into windows directly. After rebooting from windows, I got stuck on this grub screen instead of loading into windows. I’m working on a DELL Inspiron. I've tried booting into the DELL recovery and startup manager but it goes straight to this error on grub again. The error: "Minimal BASH-like line editing is supported. For the first word, TAB lists possible command completions. Anywhere else TAB lists possible device or file completions." Also whenever I type into the grub thing I get random letters instead of the ones I press. PLEASE HELP ME!! Also I’ve tried typing command ‘exit’ but that doesn’t work for me. I’ve tried other solutions and nothing works. I’m stuck and can’t load into windows In any way. Please please please help me!

I have absolutely no experience with Linux, and I desperately need to get my computer back up and running again with Windows.  How do I remove Ubuntu and reinstall Windows?    Editor's note: many of the answers are about removing Ubuntu from dual-boot but keeping Windows (which is a bit complicated), while other answers are about removing Ubuntu from single-boot (which is easy: basically just format the disk while installing Windows). The question as written is ambiguous between dual-boot or single-boot.


I am trying to call one URL through apex callouts but it is throwing this exception : "sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target" The same call is working with Postman/RESTlet Client. Can anyone tell me the exact issue. I am not getting it.

When we try to send some data to an external web service (REST, POST, JSON), we get the next error:     System.CalloutException: sun.security.validator.ValidatorException:   PKIX path building failed:   sun.security.provider.certpath.SunCertPathBuilderException: unable to   find valid certification path to requested target   If we check the certificate, it's a valid "Go Daddy Secure Certificate Authority - G2".  Also, We have checked that this company is included as a valid Certificate Authority into Salesforce list ().


I would like to have an image centered horizontally and vertically in a div which is also centered (horizontally) in another div.  Something like this:   I imagine this being done like this:

     But I can't manage to find the right CSS rules to achieve this arrangement. Some help would be very much appreciated!

I want to center a div vertically with CSS. I don't want tables or JavaScript, but only pure CSS. I found some solutions, but all of them are missing Internet Explorer 6 support.
Div to be aligned vertically
   How can I center a div vertically in all major browsers, including Internet Explorer 6?


When I don't know if a person is male or female, what word shall I use? I don't know but in spanish we use the male form: he. PD: I know that I could say He/She but I don't want.

I think that referring to a non-specific indefinite person like everyone, anyone, someone etc. as "they" is grammatical and widely accepted as being natural at least in informal speech. For example, the sentence "Everyone did their best" is grammatical. However, what about referring to a specific definite person? Let's consider the following conversation.  "My friend just got back from the shop." "What did they get?" "They bought furniture for their new apartment." "Are they married?" "Yes, they are."  Are these grammatical? Here's another example. A quote from the novel "A Study in Scarlet" written by Arthur Conan Doyle in 1886.  "What do you think of that?" cried the detective, with the air of a showman exhibiting his show. "This was overlooked because it was in the darkest corner of the room, and no one thought of looking there. The murderer has written it with his or her own blood.  Let's replace "his or her" by "their". Is the sentence "The murderer has written it with their own blood." grammatical in present-day English?


This has happened to me a couple of times now. I visit a new Stack Exchange community where I don't normally frequent. I feel like maybe my question belongs there, but I fear it might also fall into the off-topic category based on that community's rules.   Where do I go to view the rules though? Maybe they are buried somewhere in the Meta, where I will find a post that explains some of them, but is that all of them? It seems like this is a grey area.  I know the sites are very different in nature, but I'm imagining something like reddit's “Rules” column. It's specific to each subreddit, and you always know where to look for it. I'm not saying SE should be more like reddit, just offering an example I hope will be easily understood.  So, what do you all think? Would you welcome such a feature? Or does it exist somewhere and I just don't know where? Come to think of it, I'm not even sure if this question is on-topic. But I don't know where to look to check....

This is my usual experience:  "I want to post a question but I don't know what kind of questions are within the rules on this site. And since I don't want a question that took me 10 minutes to write to be instantly flagged as off-topic, deleted or down-voted into oblivion I won't post until I know the rules."   But the rules are nowhere to be found. The short site description is often not enough and doesn't include any extra information, for example Server Fault says "Q&A for server administrators" and nowhere does it say "Don't post questions about home servers on Server Fault" etc.  With the increasing amounts of new users wouldn't it be a good idea to have the rules defined on the front page of each site like on reddit for example?


The image shows the output when I try to install VLC for last 8 hours i have read all stuff on the same problem tried everything Yesterday I installed Ubuntu first time and also am not a programmer. there is some issue when I am trying to update my system, which cannot be resolved by existing solutions on askubuntu The error is  W: Failed to fetch   Unable to find expected entry 'universe/binary-amd64/Packages' in Release file (Wrong sources.list entry or malformed file) E: Some index files failed to download. They have been ignored, or old ones used instead.  Output I got : cat /etc/apt/sources.list deb http://archive.ubuntu.com/ubuntu trusty main universe restricted multiverse

I have unistalled and reinstalled the Ubuntu Software Center as per info I found in a similar thread and I got the same response about line 91 or something like that.  I just tried to upload a screen shot but since I'm new it won't allow me to.  I also can not figure out how to cut and paste anything so I have to hand type what the error screen says, both when I attempt to open the software center and nothing happens, when I try to enter commands into the terminal to uninstall, reinstall, whatever I get the same following:  COULD NOT INTITIALIZE THE PACKAGE INFORMATION An unresolvable problem occured while initializing the package information Please report t:his bug against the 'update-manager' package and include the following error message: 'E: Malformed line 91 in source list/etc/apt/sources.list (dist parse)  E: The list of sources could not be read.,  E: The package list of status file could not be parsed or opened.   How do I report bugs?  What can be done about this.  I have searched and everything everyone says to do leads me back to the same line error message.  So, I don't know how to get to line 91 in the source list; to tell you what it says. Sorry, I'm really new to this. That is what I need is to find out how to get there and fix what it says. I would really like to NOT have to re partition my hard drive and start from scratch, so I'm really looking forward to getting this problem solved. I need to be able to install new software.


I've noticed lately that depending on what zoom level I'm viewing my document in Adobe Acrobat, my table borders will disappear and come back. For example, here is a table in my most recent homework seen at 125% zoom:  Here is the same document, now viewed at 150% zoom:  I write my documents in Overleaf, and it happens no matter which machine I'm on (school and home).  I guess in the grand scheme of things it's no big deal, but it does bother me to think my documents may not be displaying as I want them to on the receiving if the person viewing it changes their zoom. Any ideas?

I'm using the xcolor package to colour the top row in a table. This is displayed properly using PDF viewers such as Preview or Skim (Mac). But using Adobe Reader 10.1.3 (either Windows or Mac) doesn't display the table line properly.   But removing the colouring for the table fixes it. Here is the example that works as expected:  \begin{table} \caption{Table showing Feature 5's Functional Tests} \hspace*{-0.5in} \begin{tabular}[h!]{|p{0.6cm}|p{4cm}|p{5cm}|p{4cm}|p{1.5cm}|} \hline {\bf Test ID } & {\bf Task } & {\bf Expected} & {\bf Actual} & {\bf Outcome} \\ \hline    5.1 & Something &  Something & Something &  Success \\ \hline    5.2 & Something &  Something & Something &  Success \\ \hline    5.3 & Something &  Something & Something &  Success \\ \hline    5.4 & Something &  Something & Something &  Success \\ \hline \end{tabular}  \end{table}   And here is the example with a coloured row:  \begin{table} \caption{Table showing Feature 5's Functional Tests} \hspace*{-0.5in} \begin{tabular}[h!]{|p{0.6cm}|p{4cm}|p{5cm}|p{4cm}|p{1.5cm}|} \hline \rowcolor{gray!25} {\bf Test ID } & {\bf Task } & {\bf Expected} & {\bf Actual} & {\bf Outcome} \\ \hline    5.1 & Something &  Something & Something &  Success \\ \hline    5.2 & Something &  Something & Something &  Success \\ \hline    5.3 & Something &  Something & Something &  Success \\ \hline    5.4 & Something &  Something & Something &  Success \\ \hline \end{tabular}  \end{table}   Removing the \rowcolor{} command replacing it with \cellcolor{} creates the same view. Any idea how to fix this?  I've tried printing it out of Adobe and the lines print fine, but as this will be read on as a soft copy it's pretty important. .  Any idea how to fix this?


Let scalar field $f : \mathbb{R}^n \to \mathbb{R}$ be given by $$f(x) = x^TA^TAx - \lambda( x^T x - 1)$$ where $A$ is an $n \times n$ matrix and $\lambda$ is a scalar. How to compute the gradient $\nabla f$? I know that it would be the Jacobian matrix (or gradient), but is there a faster way to compute it rather than writing out everything in terms of components and taking partial derivatives? The reason I ask is my classmate, when we considered this function in class, was able to compute the derivative as $A^T A x - \lambda x$ rather quickly.

It's stated that the gradient of:  $$\frac{1}{2}x^TAx - b^Tx +c$$  is   $$\frac{1}{2}A^Tx + \frac{1}{2}Ax - b$$  How do you grind out this equation? Or specifically, how do you get from $x^TAx$ to $A^Tx + Ax$?


Given some Dictionaries  Dictionary<string, string> GroupNames = new Dictionary<string, string>(); Dictionary<string, string> AddedGroupNames = new Dictionary<string, string>();   I am unable to merge them into one:  GroupNames = GroupNames.Concat(AddedGroupNames);   because "the type can't be implicitly converted". I believe (and my code proves me true) their type is the same - what am I overlooking?

What's the best way to merge 2 or more dictionaries (Dictionary<T1,T2>) in C#? (3.0 features like LINQ are fine).  I'm thinking of a method signature along the lines of:  public static Dictionary<TKey,TValue>                  Merge<TKey,TValue>(Dictionary<TKey,TValue>[] dictionaries);   or  public static Dictionary<TKey,TValue>                  Merge<TKey,TValue>(IEnumerable<Dictionary<TKey,TValue>> dictionaries);   EDIT: Got a cool solution from JaredPar and Jon Skeet, but I was thinking of something that handles duplicate keys. In case of collision, it doesn't matter which value is saved to the dict as long as it's consistent.


I Dm this guys he’s really nice and says he only wants a companion I talk to him for awhile and we agree to $300 a week but he wants me to cash app him 25$ so he can trust me. I even asked if I could give him 10 and send him the rest later and he said okay. He said he’d send me the money as soon as I did.

I met a guy on a sugar daddy dating site and we talked, I told him my situation and he said he would help.   He asked for my bank account information and I told him you can use cash app or PayPal to go through. He said his account manager deals with his finances. So I set up an account with a bank that I don’t use so that my primary account isn’t used.  Eventually he was in the process of sending me money and we had agreed on a amount that wasn't crazy. But then he asked for my address and I asked why and he said just wondering. Then said he wanted to send me a surprise for being his baby. Which I didn’t give.  Then later on he sent the money and said he sent me a bonus and that I was supposed to use that to pay his mothers caregiver, which he didn’t mention until after.  I kept questioning him and he was saying that he works in construction and he’s trusting me to carry out the errand. Then he said don’t let him down and I asked him if he was threatening me and he kept saying I need this done but didn’t really answer my question.  Am I being scammed? I’m about to change my password but is this a scam?


I have a problem when starting Windows using grub (Ubuntu 18.04). The boot screen is messed up. When starting Windows directly [by selecting Windows Boot Manager from UEFI? It doesn't appear in the video.] everything is normal.  I tried changing the resolution in grub from lowest to higher and nothing changed. I have uploaded a video that shows what is happening.

I installed Windows on my computer, followed by an installation of Ubuntu. However, now I'm unable to boot into my Windows install.  What can I do to fix this?


12 years ago, I was convicted for false document deception for 12 months and was deported from the UK to Kenya. However, I didn't disclose my real details including DOB throughout the incident, I only gave different details. Now I just got a new passport with my real details and real DOB. Can I travel to Schengen countries like France, Germany etc? Will they discover my conviction and deportation through fingerprints? Thanks.

When certain nationalities of people want to travel in the Schengen zone, they are required to apply for a Schengen visa. This is a straight-forward process for most, but when an applicant has had problems with removals or refusals they may be reluctant to apply because they want to avoid the complexities of serial visa refusals. This reluctance may lead some into wondering how their history can be expunged, and this line of thought inevitably leads to the idea of getting their passport replaced with a new one.  This sounds like a great formula for people who have had prior refusals or removals.  In essence they can become 'reincarnated' as a first-time traveller and hence avoid the unpleasantness of revealing their prior interactions with the Schengen authorities.  The relevant parts of the application form are shown here...    Nothing asks about a prior removal or refusal, and the applicant is left with simple denials for 3 questions in order to present themselves as a first-time traveller.  Assuming the person is happy to set aside the moral issues associated with denying their history, are there any holes to this strategy?  This question is scoped to Schengen visa applications so that it will not be unmanageably broad, but answers from other regimes (particularly the affluent Commonwealth and the USA) are acceptable as long as the main points are relatively consistent with Schengen.


this is my first question.  I'm looking for an evernote type application for ubuntu. Basically a way to "cloud store" terminal recipes (like a blog reminder) that I can access later either in ubuntu or in my android smartphone.  Any help or recomendations would be much appreciated  Best regards

Evernote is a cool site for capturing note, tagging it and retrieving it from everywhere. The Web application is nice but I was wondering if anyone knows about a standalone version such as for Windows, Android,... but for Ubuntu ?  Thanks !


Suppose $f:R\rightarrow R'$ is an epimorphism of rings with identity, can we have   $f(1_R)=1_{R'}$ ?   I think I should assume that $f(a)=1_{R'}$, but I don't know how to continue. Thanks for any help in advance.

Possible Duplicate:          I'm studying the Atiyah's commutative algebra book and I realized that in the beginning of the book, the author says as one of the conditions to a map be a homomorphism is $f(1)=1$, I would like to know if I can left this condition behind, i. e., if $f(x+y)=f(x)+f(y)$ and $f(xy)=f(x)f(y)$ we can have $f(1)=1$.  Thanks


#include <iostream>  #include "Pizza.h"  int main() {   iFood* food;  food = new Pizza(14.0, 8);   for (int i = 0; i < 3; i++)      food->consume();  food->display();  std::cout << std::endl;   delete food;   food = new DeluxePizza(12.0, 6, "mushrooms, peppers");   for (int i = 0; i < 2; i++)      food->consume();  food->display();  std::cout << std::endl;   delete food;  }   This is my main.cpp when I run this code, it shows the warning that delete called on iFood that is abstract but has non-virtual destructor.

I know it is a good practice to declare virtual destructors for base classes in C++, but is it always important to declare virtual destructors even for abstract classes that function as interfaces? Please provide some reasons and examples why.


Upon applying the Cantor diagonal argument to the enumerated list of all computable numbers, we produce a number not in it, but seems to be computable too, and that seems paradoxical.  For clarity, let me state the argument formally. It suffices to consider the interval [0,1] only. Consider $0 \leq a \leq 1$, and let it's decimal representation be found as $$ a =\sum_{n=1}^\infty 10^{-n} a^{(n)} $$ We say that $a$ is computable, if there is a Turing machine $T_a$ which receives $n$ and outputs $a^{(n)}$ in finite time, i.e., it always halts.  Let $A$ be the set of all computable numbers. A moment's reflection shows that $A$ is countably many. For example, we can implement $T_a$ in (say) Python, always choosing the program with the shortest string length, and we sort $T_a$ by their program according to the ASCII characters' dictionary order. If two programs, which both implement $T_a$, have the same string length, choose the one with foremost dictionary order. This gives a sorting function of $A$.  Let $A$ be enumerated with $a_1, a_2, a_3 \dotsc$. Now, construct a number $b$ so that: $$ b =\sum_{n=1}^\infty 10^{-n} b^{(n)} \\ b^{(n)} =\begin{cases} 4,\quad a_n^{(n)} =3 \\ 3,\quad \rm{otherwise} \end{cases} $$ We see $b \notin A$. Moreover, $b^{(n)}$ is obtained within finite time, since we only need to know $a_n^{(n)}$'s value. Thus $b \in A$, but $b \neq a_n$ for all $n =1,2,3, \dotsc$, a contradiction.   is related, but I don't think it's a duplicate. The post applies the diagonal argument on the reals, rather than the computable numbers.

Let O be a computable ordering of all computable reals in ⟨0,1) (eg. first by length of programs computing them and then lexicographically). (it does not matter that they appear there more than one time). It seems to be possible to produce a computable real not in this ordering by diagonal argument, using a deterministic algorithm to produce the non-matching digit.  What is the error in this reasoning?


Across the Stack Exchange network, the original poster appears in the lower right, with any edits then appearing to the left of that.  I'm not sure when it changed, but the mobile app (iOS, v 1.6.3.6) seems to be displaying this information in a different way to how it used to; the original poster is now on the left, with any edits being shown on the right.  It's a minor thing, but not having it consistent with the network means my eye is drawn to the wrong person a lot of the time.  The latest one being a comment on a Q saying "welcome to stack...", and a brief moment of confusion because the asker had 4k+ of rep.  Only they weren't the asker, they were an editor...    Can these elements be swapped over please?

The new attribution style on posts looks great, and brings some consistency with the website which is good. This is how it looks on an iPhone (in landscape, to emphasise the alignment; in portrait both boxes take up the whole screen width):        This is how it looks on the website:        Notice the switched order? That's confusing. Since the app version is aligned left it does make more sense in the order that it is, but since the website version is right aligned and the idea here is obviously consistency with the website could we switch the alignment and order to match?


Let $ a_1,a_2,a_3 >0$ $\lambda_1\lt \lambda_2 \lt \lambda_3 \in \mathbb{R}$ prove that the following equation has exactly 2 solutions $\dfrac{a_1}{x-\lambda_1} + \dfrac{a_2}{x-\lambda_2} + \dfrac{a_3}{x-\lambda_3} = 0$  this should be closely related the continuity and the intermediate value theorem, but i couldn't connect the dots on this one.

Question:  Given $\lambda_1<\lambda_2<\lambda_3 \in \Bbb R, a_1,a_2,a_3>0 $  Show that this equation has exactly 2 solutions:  $\frac {a_1}{x-\lambda_1}+\frac {a_2}{x-\lambda_2}+\frac {a_3}{x-\lambda_3}=0$  What I did: Try 1: Since we are studying continuity, Weirstrass theorem and Mean value theorem at the moment, I think one of these theorems should somehow be involved in the proof... Assuming that x is not equal to any of the lambdas I multiplied by the denumerators and got a quadratic equation- From this I figure that there must be at most 2 solutions. I thought about using the discriminant to prove that that there are exactly 2, but the calculation is very long, and I don't think this is what the lecturer intended for us to do, considering what we are studying now.  Try 2: Thought of using the Intermediate value theorem. So I defined a function $f(x)=\frac {a_1}{x-\lambda_1}+\frac {a_2}{x-\lambda_2}+\frac {a_3}{x-\lambda_3}$ and I want to find when it equals 0.  but Intermediate value theorem only involves two lambdas, and also I don't know if the lambdas are negative or positive (some/all of them)- Should I divide to cases?  Hints are welcome at first :-)


I met a statement, that  disobeys the third Newton's law.  Is this true?   Also I met some setups, where it was stated, that third law is violated. Also I met some explanations about WHY it is violated, saying that momentum is transferred to the field, like in "duplicate" question:   But my question is different. I am disputing the fact itself. Is this really true, that it is possible to observe third law violation (i.e. momentum leak) in table experiments?  For illustration suppose we have two conducting parallel horizontal plates and two perpendicular horizontal rods between them. Rods have contacts with plates, so that one end of each rod is contacting one plate and another end is contacting another. Contacts go vertical, but they are infinitesimally small and we can ignore forces, induced by them.  So, two rods are perpendicular and have current flowing through them.     Magnetic field of red rod is shown by red ellipse. It reaches blue rod in the center and since it's perpendicular to the current, it applies a force to blue rod, shown by black arrow.  Magnetic field of blue rod is not shown. But it's geometry implies that red rod falls into the center of symmetry. So, there is no magnetic field, applied to red rod.  The question is: will the momentum lack be observable here?  This setup is taken from "duplicate" question setup, where two charged particles were moving. But I am not insisting on this setup.  Please suggest ANY other setup. I have my laboratory table, have wires, batteries, have Wimshurst machine etc.   Can I observe third law violation? If "yes" then "how"?

Consider a system of the two identical positive point charges situated in free space (isolated from the influence of any other external fields) as shown in the attached diagram. Particle $1$ is at $(a,a,0)$ and particle $2$ is at $(0,a,0)$. Their velocities, at the considered instant of time, are as shown in the diagram ($\mathbf{v}_1$ along the $+x$ axis, $\mathbf{v}_2$ along the $+z$ axis).    Now, by applying the Biot-Savart law, we find that the magnetic field due to particle $2$ at the position of particle $1$ is along $+y$ axis, which means that the force acting on particle $1$ is along $+z$ axis according to Fleming’s left-hand rule. A similar analysis shows that there is no magnetic force on particle $2$ as the magnetic field of particle $1$ should vanish at positions (relative to particle $1$) located along its velocity vector.  Now, if we observe the net torque on the system of two particles about the $y$ axis then it is non-zero and is directed along the $-y$ axis. Here, there are no external forces or torques acting on the isolated two-particle system, and yet the net torque, as well as the net force on the particles, are nonzero. Why? Also, Newton's third law of motion seems to be broken in this scenario. Why?    Edit $1$  I have come to know from the responses that the electromagnetic field itself takes away some momentum and angular momentum about the considered axis. However, I think that if I consider only two charged particles as my system then the Abraham-Lorentz force can be assumed to be acting upon the system, and that is sufficient to make sure that we have considered the momentum being carried away by the electromagnetic field itself.   Even after considering the action of the Abraham-Lorentz force for the two-particle system, the scenario breaks both Newton's third law and the conservation of linear and angular momentum. This is because the Abraham Lorentz forces do not exactly counterbalance the force and the torques, on the two-particle system under consideration, due to the magnetic field.    Edit $2$  The previous edit was a result of confusion and misunderstanding on my part. The force associated with the momentum carried away by the electromagnetic field as a result of the electromagnetic interaction described in the question is the Lorentz force itself which simply doesn't obey the third law of motion. The Abraham-Lorentz force is a different story. It is associated with the momentum carried away by the radiation emitted by the accelerated charged particles. This is an additional force apart from the Lorentz force and corresponds to an additional carriage of momentum by the electromagnetic field. The momentum carried away by the electromagnetic field in correspondence with the Lorentz force doesn't correspond to radiation.


Is there a way  to do: output | grep "string1" | grep "string2"   BUT with awk, WITHOUT PIPE? Something like: output | awk '/string1/ | /string2/ {print $XY}'  Result should be subset of matches, if tha makes sense.

I would like to get the multi pattern match with implicit AND between patterns, i.e. equivalent to running several greps in a sequence:  grep pattern1 | grep pattern2 | ...   So how to convert it to something like?  grep pattern1 & pattern2 & pattern3   I would like to use single grep because I am building arguments dynamically, so everything has to fit in one string. Using filter is system feature, not grep, so it is not an argument for it.    Don't confuse this question with:  grep "pattern1\|pattern2\|..."   This is an OR multi pattern match.


This is a two part question  Given $\gcd(a,b) = 1$  consider  $$\gcd \left( \frac{a^n - b^n }{a-b}, a- b\right) $$  It appears that the value of this is always equal to $n$ or $1$. How to prove it?  And with that show  $$\gcd \left( \frac{a^n - b^n }{a-b}, a- b\right) = \gcd \left( n \frac{a^{n-1} - b^{n-1}}{a-b}, a- b \right) $$  I began with tackling the first part  I trie to use an Inductive Proof at first by noting:  $$\frac{a^{n+1} - b^{n+1}}{a-b} = a\frac{a^{n} - b^{n}}{a-b} + b^{n} = b\frac{a^{n} - b^{n}}{a-b} + a^{n} $$  But this didn't pan out any sort of solution since it doesn't become immediately apparent that $n+1$ divides this new quantity or some linear combination of this quantity with $a - b$  I could attempt a combinatorial approach and ty to use the binomial theorem I was thinking. But no apparent way to match terms become apparent.  What should I do for the first part?

How to show that     $$ \gcd\bigg( {a^n-b^n \over a-b} ,a-b\bigg )=\gcd(n d^{n-1},a-b ) $$    $a,b\in \mathbb Z$   where $d=\gcd(a,b)$?    Note $\ $ Some of the answers below were merged from . The answers (and their comments) may depend on context provided in that question.


This was originally marked as a duplicate, however, I believe it is necessary to ask again as the requirements to accomplish the intent have changed significantly in the years since. Previous answers possibly no longer apply after Google's recent changes.  What are the necessary steps to achieve what is shown in the image below?  Here's what I have done so far:   Created Google+ business page for brand Linked and verified website to Google+ page Added schema.org "organization" ld+json tags to relevant pages   Yet, when I search for my brand "twolips dating", there is nothing shown to the right.

For some results returned in Google Search, on the right side it displays the company details, logo, contact numbers, etc...   For example, see the following screenshot:    I'd like to know what contributes to this so that I can try to achieve it for my site too.


What can you do when your iPhone is in Airplane Mode, the WiFi is off, and the lock button is broken. I can't log in to the phone. How can I turn it off?

Now that I know , I was wondering how I can restart the phone or turn it off.  The lock button is completely unresponsive and holding it down does nothing. Are there any workarounds besides replacing the button?


Who created the Borg concept?  Looking at  it is clear TNG had already started without the Borg as such, but with the idea that a new powerful adversary was needed.  This article suggests a collective effort in realising the Borg by the writers, but in reality it is usually one or two people who are initially responsible for a concept.  Is there a named person (or persons) responsible for the Borg, such as Gene Roddenberry and Leonard Nimoy were for the Vulcans initially or Branon Braga for Species 8472?

Captain Power and the Soldiers of the Future was a dystopian science fiction television series that aired in North America for only one season (1987-1988), and which had J. Michael Straczynski as its head writer.  The primary antagonist was "Lord Dread".  From :     With the new opportunities offered by the human-machine combination, [Dr. Lyman] Taggart becomes obsessed with the precision and "perfection" of machines and convinces himself that merging human consciousness with mechanical bodies is the next step in human evolution. OverMind [a supercomputer] achieves self-awareness and shares Taggart's beliefs as they take over Bio-Mech armies throughout the world and attack humanity in a conflict known as the Metal Wars.   Here is Lord Dread, as he appeared in the series:    Now, here is a typical Borg from Star Trek:    The Borg first appeared in 1989 (in ), two years after Lord Dread and his Bio-Mech army were introduced in Captain Power.  Given the similarity between Lord Dread and the Borg in both appearance and goals, is there any evidence that Lord Dread was an inspiration for the Borg in Star Trek?


For a dataset I ran a random forest model with sikit learn. When I checked important variables from RF , I was unable to understand the reason for choosing that variable as important.  In my understanding There would be rules for the tree built by RF. Is there a way to visualize the trees and understand the rules. Or how can I know the reason on choosing that variable as important by RF

Random forests are considered to be black boxes, but recently I was thinking what knowledge can be obtained from a random forest?  The most obvious thing is the importance of the variables, in the simplest variant it can be done just by calculating the number of occurrences of a variable. The second thing I was thinking about are interactions. I think that if the number of trees is sufficiently large then the number of occurrences of pairs of variables can be tested (something like chi square independence).  The third thing are nonlinearities of variables. My first idea was just to look at a chart of a variable  Vs score, but I'm not sure yet whether it makes any sense.    Added 23.01.2012 Motivation    I want to use this knowledge to improve a logit model. I think (or at least I hope) that it is possible to find interactions and nonlinearities that were overlooked.


I made a really stupid autoremove mistake. I was uninstalling libssl1.0.0 and it somehow said that pretty much every package I had was now not needed. I didn't really read carefully and I uninstalled a LOT of packages. I saw things like wget and node being uninstalled.  My question is, how do you install everything from sources.list, and would it be plausible to install everything from sources.list to recover from this accident?

I accidentally removed all the packages starting with the name jpeg with:  sudo apt-get remove jpeg*   This screwed up a lot of things, removed Unity, Firefox, Flash player etc.  I somehow managed to recover the desktop and unity but then a lot of things are still buggy. For example .rpm files and .tag.gz just won't open up at all.  What I want is a way to fix everything that's amiss. Something that is the equivalent of a 'repair installation' with a windows disc.  Any tips, anyone?


I'm trying to show only first result from this select, but cant figure out how to do it or what function should I use.  I have tried rownum <= 1, but it changed shown result.  select name || ' ' || surname as meno, role from system_user order by surname ASC ;

Table:   UserId, Value, Date.   I want to get the UserId, Value for the max(Date) for each UserId. That is, the Value for each UserId that has the latest date. Is there a way to do this simply in SQL? (Preferably Oracle)  Update: Apologies for any ambiguity: I need to get ALL the UserIds. But for each UserId, only that row where that user has the latest date.


I am currently on Pop!OS 20.04, and after installing zsh and setting it as my default shell, when installing apps by using apt-get like follows, zsh says no matches found: sudo apt-get install libreoffice* -y  Why does this happen, and is there a way to make this not happen again?

I have switched over to zsh, and it is working fine. One strange thing, when I try to scp with a * wildcard, it does not work, and I have to drop into bash. The second command below works fine.  Any ideas on why this would be and how to fix it?  ~/dmp ⌚ 16:06:10 $ scp abc@123:/home/se/exports/201405091107/* . zsh: no matches found: root@uf3:/home/se/exports/201405091107/*  ~/dmp ⌚ 16:06:53 $ bash  sean@seanlaptop:~/dmp$ scp abc@123:/home/se/exports/201405091107/* .


Does the series $$\sum_{n=1}^\infty  \frac {i^n}n$$ converge or diverge?  I tried to use both ratio and root tests, but I got 1 on both cases, which are inclusive.

Inspired by the exponential series, I'm curious about where exactly the series $\displaystyle\sum_{n=1}^\infty\frac{z^n}{n}$ for $z\in\mathbb{C}$ converges.   I calculated $$ \limsup_{n\to\infty}\sqrt[n]{\frac{1}{n}}=\limsup_{n\to\infty}\frac{1}{n^{1/n}} $$ and $$ \lim_{n\to\infty} n^{1/n}=e^{\lim_{n\to\infty}\log(n)/n}=e^{\lim_{n\to\infty}1/n}=e^0=1. $$ So the radius of convergence is $1$, so the series converges on all $z$ inside $S^1$. But is there a way to tell for which $z$ on the unit circle the series converges? I know it converges for $z=-1$, but diverges for $z=1$, but I don't know about the rest of the circle. For what other $z$ does this series converge? Thanks.


I use longtables to add Notes to my document. These notes shall not be counted. Can I tell longtable this (similar to \chapter* instead of \chapter)?

For reasons both complex and confusing, I would like to caption a longtable without incrementing the table counter in the process.  I want to have two consecutive longtable environments to be captioned with identical table numbers; i.e. one longtable captioned "Table x.y: Data Set (Part A)" and one captioned "Table x.y: Data Set (Part B)", with x.y being identical for both tables.  Apparently however, even \caption*{} command bumps table. I am a bit at a loss here.  Note: I know that the xtab package would enable me to have one long table with switches of headers and captions mid-table. However I got a (different) problem with that package, akin to  but sadly not solved by egreg's answer there; so this question should be considered longtable-only as xtab, supertabular etc. don't float my boat right now. :-(


In case of car movement, static friction is responsible for acceleration of car. Does the rolling friction act even when car is accelerating or it acts only when power supplied by the Engine is zero? Is that rolling friction is responsible for maintaining constant speeds of car even at low speeds; say 10kmph(in first gear)?

I am a bit confused about the relation between rolling resistance and static friction.   I have often heard that it is the static friction that lets the wheel roll. Consider the following two cases:  a) A tire of a car of mass $m$ moving with positive acceleration $a$ on a street b) A wheel of a moving wagon (of mass $m$) which is pulled by a string (with force $F_\mathrm{string}$).    How do the free body diagrams look like? (including static friction, rolling friction and friction forces at the axis) What is the resulting force accelerating the center of mass of the wheel in case b) (in dependence of the frictional coefficients and $m$)


I'm a beginner here, and I have a question about the evening/night meal, and this is my first question.      It's evening. The family is eating dinner.    From when until when is it considered to be "evening" in English? And from when until when is it considered "night"? Are these completely distinct or are they overlapping concepts? I’m an Iranian. In Iran, we consider "evening" to run all the way from afternoon until sunset (4 pm – 8 pm), while "night" for us runs from right after sunset until the next sunrise; and we eat "dinner" at night, normally around 10 o’clock at night.   So, does one eat another meal after "dinner"? It seems to me that "dinner" is an evening meal and people eat it very soon, so it should be not the meal that people eat late at night, as we do in Iran.

I've seen cases where a noon-time meal is referred to as dinner, and the evening meal is called supper. There's also lunch around noon followed by dinner in the evening. Is there a particular difference between dinner and supper, or a circumstance where lunch becomes dinner?


I was recently rejected for visas on the grounds I do not have a travel history. I have only been able to visit one nation. Other things about me:  I am a Nigerian I am a Software Engineer for a Financial institution in My home country / Remote Mobile application Developer I have been to Benin Republic (Just one country) I recently got married, April this year, No child. I have Properties in my name inherited from my father  Is this a good fit to apply for a  for Canada?

Over the course of time here on TSE, I have observed individuals whose pattern of visa applications is best described as ''...     serial refusals - Two or more consecutive visa refusals issued by the same regime to the same person. Commonly for the same, or nearly the same, reasons. In some visa regimes Serial refusals can have a cumulative effect wherein the applicant's credibility is increasingly eroded, especially when the application pattern suggests a secondary agenda.   A common thread appears to be the need to visit the destination country (especially Schengen, the USA, or the UK) with a special sense of urgency. Also common in these cases are the following types of questions...   Should I just reapply once again? What are my chances? What can I do to improve my odds in the future? Can I somehow address the previous refusals to avoid them being a burden on all future applications? How can I break the pattern?      NB: This question is intended as a canonical about serial refusals. I have never been personally denied a visa.


I am not able to change brightness on Ubuntu 17.10. Keywords function are also not functioning. There is no option of brightness control system on a Ubuntu 17.10. How to change brightness??

I just upgraded to ubuntu 17.10 and now display brightness controls are not working, and i am not able to change display brightness at all. But it was working perfectly in 17.04  I also tried this method, but still not working. When I saw system details, it shows unknown graphics.  Section "Device"         Identifier  "card0"         Driver      "intel"         Option      "Backlight"  "intel_backlight"         BusID       "PCI:0:2:0" EndSection   What can I do now?


I think this must have been questioned before, but after searching, I couldn't find it.   I thought of considering a set of $\{x_1, ..., x_n\}$ such that $\lt x_1, ... x_n\gt = A$. The hypotesis shows easily that $\lt f(x_1), ... f(x_n)\gt = A$  Also thought about having an ideal $I_1=Nu(f)$ and define $I_n$ such that I take an $x_n \in A -I_{n-1}$ and $I_n=I_{n-1} \cdot \lt x_n \gt$. Since A is Noetherian, for some m, $I_m=A$, but couldn't find a way with this to show that $f^{-1}(0)=0$ or anything else that shows that f is inyective.  One last thing I thought was the inverse of the first thought: I take a set that generates A, then the inverse of that set must generate A.   All of this trouble is because I'm assumming $A$ is infinite. If $A$ is finite it's easy because they have the same amount of elements

I am revising for my Rings and Modules exam and am stuck on the following two questions:  $1.$ Let $M$ be a noetherian module and $ \  f : M \rightarrow M \  $  a surjective homomorphism. Show that $f : M \rightarrow M $ is an isomorphism.  $2$. Show that if a semi-simple module is noetherian then it is artinian.  Both these questions seem like they should be fairly straightforward to prove but I cannot seem to solve them.


I have an array of 50 chars:  char arr[50];   I'm told that in arr[1] till arr[4], there is an int I need to get.  I did :  int *p = (int *)(arr+1);  return *p;   I was told it's a mistake. Why?

When asking about , people sometimes refer to the strict aliasing rule. What are they talking about?


I know this is a tired problem, but the solutions  and  aren't working for me so I'm posting here. I'm using blender 2.92.0. In the compositor I have a Render Layers Node going into a Glare node, and the Glare node into the Composite node with "Use Alpha" checked. On the left is the blender render with glare, on the right is the saved .png where the glare is lost in the transparency. I want the image to look like the render. Is this to do with premultiplication or something? I tried the other node configurations from the aforementioned posts, and all of them produce similar results with a functioning render and a malfunctioning png.

This is what I have so far:  The rendered image has a transparent background, but the glare filter creates an output with a black background, so after merging the two togheter, the background turns black but I need it to be transparent, what can I do?


Note: This applies to Centos 7. If you are looking for a Debian answer, see . Those answers will not be duplicated here.  After an install of centos 7, I can't access man pages :  # man ls -bash: man: command not found   I tried to install it via yum   # yum install man-pages ... ok   But again:   # man ls -bash: man: command not found   Why?

On Debian systems (and derivatives):  $ dpkg --search /bin/ls coreutils: /bin/ls   That is, the file /bin/ls belongs to the Debian package named coreutils.  But this only works if the package is installed. What if it's not?


This question might be a duplicate one, but I could not find the exact answer so I am asking it.  I am developing a Spring REST application. I want to take some images in POST request and store them somewhere in the server, which is not in the project directory, so it won't be a of the WAR file.  I will be storing image URLs in the database and sending them in GET response.  How can I do that? If there is some tutorial link that would be helpful.

I'm writing an application that allows users to upload images onto the server. I expect about 20 images per day all jpeg and probably not edited/resized. (This is another question, how to resize the images on the server side before storing. Maybe someone can please drop a .NET resource for that in the comment or so).  I wonder now what the best place for storing uploaded images is.   Store the images as a file in the file system and create a record in a table with the exact path to that image. Or, store the image itself in a table using an "image" or "binary data" data type of the database server.   I see advantages and disadvantages in both.  I like a) because I can easily relocate the files and just have to change the table entry. On the other hand I don't like storing business data on the web server and I don't really want to connect the web server to any other datasource that holds business data (for security reasons)  I like b) because all the information is in one place and easily accessible by a query. On the other hand the database will get very big very soon. Outsourcing that data could be more difficult.


I have seen that (for $p$ prime) $\mathbb{F}_{p^m} $ is a subfield of $\mathbb{F}_{p^n}$ if and only if $m$ divides $n$. But my question is in what sense? Surely as long as $m\leq n $ then it is a subfield since $\mathbb{F}_{p^m} \subset \mathbb{F}_{p^n}$ and $\mathbb{F}_{p^m}$ is a field in it's own right - so it is a subfield? Why is this wrong?

We know that if a finite field $F$ has characteristic $p$ (prime), then $F$ has cardinality $p^r$ where $r = [F:\mathbb{F}_p]$.   I'm now trying to say something about the possible cardinalities of subfields of $F$. I can see that there is a subfield of cardinality $p^s$ for each $s$ that divides $r$, given by the fixed field of the group generated by $\phi^s$, where $\phi$ is the Frobenius automorphism.  Now suppose $K$ is a subfield of $F$. Then (since both are additive groups), Lagrange gives us that $|K|$ divides $|F|$, so $|K| = p^t$ for some $1 \leq t \leq r $ (alternatively, $K$ contains $\mathbb{F}_p$ and so is a vector space over $\mathbb{F}_p$ and is thus isomorphic to $\mathbb{F}_p^t$, where $t = [K:\mathbb{F}_p]$). By considering the multiplicative group of units of $K$ and $F$ respectively, we get that $ p^t - 1$ divides $p^r -1$. I want to make the leap to $t|r$, but I'm failing to see why this needs to be true. Any help would be appreciated.


Before downloading, there is an option to choose 32 bit or 64 bit, but It says only newer PC's. Can I still install this OS on my old 64 bit PC?

I'm thinking about installing Ubuntu Desktop, but I don't know what flavor is the best for my system. What are the minimum and recommended hardware requirements? What kind of CPU? How much memory? Should I have Hardware Acceleration? What flavor should I use?  This is an attempt of a canonical answer. My answers have the "official  requirements", the recommended are a mix of official sources and opinion based (along with the answer it's told the source). You can comment or edit if you feel that the information is obsolete or incomplete. It is a good rule of thumb that any system capable of running Windows Vista, 7, 8, x86 (Intel) OS X will almost always be a lot faster with any Ubuntu flavor even if they are lower-spec than described below.


I am trying to create a Single page application.  html content:

   All my application content will go inside contentDiv along with ng-view.  css content:  .containerDiv { position: relative; min-height: 100%; background-color: beige; }  .headerDiv { height: 60px; background: black; width: 100%; }  .contentDiv { padding-bottom: 60px; }  .footerDiv { position: absolute; left: 0; bottom: 0; right: 0; background-color: pink; width: 100%; height: 60px; }   Everything works fine with non-positioned elements and footer stay at the bottom, when content height increases.  I want to add positioned elements(absolute or relative) in the contentDiv as per my requirements.  When height of my positioned element increases, it breaks my page as footer remains at same position and elements overrides it.  Suppose I want to add a table in contentDiv

   I want to align table at particular location in html.  .data{  position:absolute/relative;  top: 300px;  left: 400px; }   If height of the table increases, it will go out of the scope of footer. The height of the table is dynamic.

I have a simple 2-column layout with a footer that clears both the right and left div in my markup.  My problem is that I can't get the footer to stay at the bottom of the page in all browsers.  It works if the content pushes the footer down, but that's not always the case.


I was toying with the concept of array pointers. I wrote this simple program:  #include <stdio.h>  int main (int argc, char **argv){     char s[] = "Hello world!\n";     char *i;     for (i = s; *i; ++i){         printf(i);     }     return 0; }   which gives the very amusing output:  Hello world! ello world! llo world! lo world! o world!  world! world! orld! rld! ld! d! !   When I wrote this, however, I was under the impression that the output would start from the second row. Reason being, in the for loop, I use a pre-increment notation. i is set to the beginning of s, the Boolean condition is checked and it holds true, then i gets incremented and the block executes.  That was my impression, but obviously it is erroneous as the block executes before i gets incremented. I rewrote the program using a post-increment notation and got exactly the same result which confirms my hypothesis. If that is the case, then how are they treated differently in this program?

In C, what is the difference between using ++i and i++, and which should be used in the incrementation block of a for loop?


Which of the following choices makes this sentence is grammatically correct? or is there a better approach?     It's unclear whether he/him or I/me is/are first in line.

I was watching the film A Game of Shadows starring Robert Downey Junior and Jude Law when this line came up, "...neither you nor I is in control..." (I can’t remember the exact words that ended the phrase; if anyone can supply them, it would be much appreciated.)   It immediately struck me as being odd. When I mentioned this to my boyfriend; an English native speaker, with a PhD in something sciency, he told me it was correct. When I asked why, he couldn't explain but put forward the following sentence as an example. "Neither of us is in control..." However, I disagreed with the wording and said the sentence should have been: "Neither one of us is in control..." The genderless third person, one, is singular, and hence, so too the verb that follows. And we say, "one is" NOT "one are".      "Neither you nor I are in control over ..."    I believe the above sounds better, but it is more logical to say:     "Neither you nor I am in control..."    because the verb agrees with the subject closest to it; however, I'm not sure if I have ever read or heard this solution. So, I tried inverting the subject and auxiliary verb order and the resulting phrase was:    "Neither you nor am I in control..."    which sounds very formal, pompous, and ... odd. Am I imagining things?  The two subjects you and I are two separate individuals who are not joined together, I agree the verb should be in the singular; but why should we use "is"? We don't say, "you is" or "I is". Before anyone rushes off to claim my question is a duplicate of a previous Stackexchange one:  I want to explain why the answer to that question fails to explain why my boyfriend and the film makers consider the  sentence below correct:     Neither you nor I is in control...   As I see it, Michael and Albert are two separate individuals, it therefore stands to reason that the verb should be singular, and "is" agrees with the subject. If I rephrase the neither and nor construction, I would get:          Michael is not correct but neither is Albert   OR          Michael is not correct and Albert isn't either.      Which have the same meaning, (either being the negative equivalent of neither) the sentences are grammatical which leads me to conclude that the verb must be singular and hence         Neither Michael nor Albert is correct      However, when I rephrase the "neither you nor I" sentence following the same procedure I have to say this:        You are not in control but neither am I (‘I am’ is ungrammatical)   OR              You are not in control and I’m not either.      which leads me to surmise that the sentence below must be grammatically correct        Neither you nor I am in control"      So, why does my boyfriend insist that the sentence ought to be:     Neither you nor I is in control   Which one of us is right and why?


I know some people have asked about the difference between a semicolon and double ampersand to chain commands. But what I see in , is SINGLE ampersand. What does it mean? What's the difference between these two lines of codes: /opt/mssql/bin/sqlservr & /usr/src/app/import-data.sh & npm start  /opt/mssql/bin/sqlservr && /usr/src/app/import-data.sh && npm start

In tutorials and how-to's I often see commands combined. For instance,  sudo apt-get update && sudo apt-get install pyrenamer   There seem to be four possible connectors: &, &&, || and ;. Though the &  connector is clear to me (it sends a process to the background and leaves the terminal available), it is not clear what the difference is between && and ;. And I did not know of || until Kaya's comment.  The following questions deal with the difference between the two connectors, but do so mostly in the comments:        So here are a number of related questions:   What is the difference between ; and &&?  When should you use them respectively? It would be nice to see some use cases: if I want to run a command and then after it shutdown my computer, which connector should I choose? What are their advantages and dangers?  mentions in a comment to  that a command like cd /somewhere_else; rm -Rf * can have destructive consequences if the first element in the command chain fails, for instance. If relevant, where do they come from?


I have a file of genomic data with tag counts, I want to know how many are represented once:  $ grep "^1" file |wc -l   includes all lines beginning with 1, so it includes tags represented 10 times, 11, times, 100 times, 1245 times, etc. How do I do this?  Current format 79      TGCAG..... 1       TGCAG..... 1257    TGCAG..... 1       TGCAG......   I only want the lines that are:  1       TGCAG.....   So it cannot include the lines beginning with 1257. NOTE: The file above is tab delimited.

I have a text file:  deiauk 1611516 afsdf 765 minkra 18415151 asdsf 4152 linkra sfsfdsfs sdfss 4555 deiauk1 sdfsfdsfs 1561 51 deiauk2 115151 5454 4 deiauk 1611516 afsdf ddfgfgd luktol1 4545 4 9 luktol 1   and I want to match exactly deiauk.  When I do this:  grep "deiauk" file.txt   I get this result:  deiauk 1611516 afsdf 765 deiauk1 sdfsfdsfs 1561 51 deiauk2 115151 5454 4   but I only need this:  deiauk 1611516 afsdf 765 deiauk 1611516 afsdf ddfgfgd   I know there's a -w option, but then my string has to mach whole line.


Can I put a single Nvidia Geforce GTX Titan X in my Dell Precision T1700.  Here are some details about my configuration in this gist:   It says Up until 90% efficiency 365W, (Thunderbolt compatible).

Note: This is intended to become a canonical post.  I got a dedicated graphics card of type XXX and it claims I need at least a YYY Watt PSU.   How big does my PSU really need to be?


For me it´s not really clear, because it´s possible to keep it in singular in German.   which version correct?  The Motor front and the motor rear bearing "has" or "have" been replaced?  Thanks in advance ;)  Kind regards

Can anyone tell me if I should use inspire or inspires in this phrase?     An extraordinary leader whose vision, values, integrity and boundless curiosity inspires all who follow in his footsteps.


Let $C_c(\mathbb{R})$ be the following:  $$C_c = \{ f \in C(\mathbb{R}) \mid \exists T > 0 \text{ s.t. } f(t) = 0  \text{ for } |t| \geq T\}$$  Let $T_n \in L(C_c(\mathbb{R}))$ be a linear operator such that:  $$T_n u = \delta_n *u, \forall u \in C_c(\mathbb{R}),$$  where  $$ \delta_n(t)= \begin{cases}        n^2(t+1/n) & -1/n \leq t \leq 0 \\       -n^2(t-1/n) & 0 < t \leq 1/n \\       0 & \text{elsewhere}     \end{cases} $$  I have to prove that with respect to the 2-norm, the operator $T_n$ has $\|T_n\| = 1.$  I cannot use the Young's convolution inequality directly, but I have to use the properties of the Fourier's transform.  So far, I was trying to do the following:  $$\|\delta_n * u\|_2 = \|\mathfrak{F}(\delta_n * u)\|_2 = \|\mathfrak{F}(\delta_n ) \mathfrak{F}(u)\|_2 $$  But then I was wondering how to proceed.

Let $C_c(\mathbb{R})$ be the following:  $$C_c = \{ f \in C(\mathbb{R}) \mid \exists \text{ } T > 0 \text{ s.t. } f(t) = 0  \text{ for } |t| \geq T\}$$  Let $T_n \in L(C_c(\mathbb{R}))$ be a linear operator such that:  $$T_n u = \delta_n *u, \forall u \in C_c(\mathbb{R}),$$  where  $$ \delta_n(t)= \begin{cases}        n^2(t+1/n) & -1/n \leq t \leq 0 \\       -n^2(t-1/n) & 0 < t \leq 1/n \\       0 & \text{elsewhere}     \end{cases} $$  I have to prove that with respect to the 2-norm, the operator $T_n$ has $\|T_n\| = 1$ and I have succeeded in proving that $\|T_nu\|_2 \leq \|u\|_2, \forall u \in C_c(\mathbb{R}).$  Now, I remained  to prove that $\exists \text{ } u \in C_c(\mathbb{R}) \text{ s.t. } \|T_nu\|_2 = \|u\|_2$, but I really don't get how $u$ should be shaped in order to satisfy it.


BACKGROUND  A UNIX NAS operates behind a Unix Router.  The router's SSH port is open to the WAN, however the SSH port of the NAS is LAN accessible only.  One is able to SSH to the router from any WAN connections (i.e. Starbucks) from Unix command line (Bash).  To access the NAS, one must provide login through the router and then login to the NAS.  QUESTION  Is it possible to remotely retrieve (from NAS side of router) files from the NAS via:    command-line (scp, rsync, etc)? application (FileZilla)?   Examples are preferred & appreciated.

Three server A,B & C. How to ssh connect from A to C via intermediate server B, if A to B & C to B are password less(key)? I encountered this in an interview. Anyone knows how?


Here is an excerpt from The Hitchhiker's Guide to the Galaxy:     'He threw away a copy of Joseph and the Amazing Technicolor Dreamcoat , he threw away a copy of Godspell: he wouldn't need them where he was going.'   My understanding is that independent clauses should be separated by a conjunction, a semi-colon, or a full-stop. Therefore, shouldn't this sentence read     'He threw away a copy of Joseph and the Amazing Technicolor Dreamcoat ; he threw away a copy of Godspell: he wouldn't need them where he was going.'   Although I think the second sentence is technically correct, I would say that the first sentence is more natural. If commas and semi-colons can be thought of as cues for how long we should pause when reading a sentence, then the first sentence is a clear winner. So is Douglas Adams breaking a punctuation rule in the interests of readability, or is no rule being broken at all?

It's always drilled into us that we shouldn't use comma splices. They're bad, to be avoided and poor form.  But why? What makes the comma a faulty choice in something like this:     I never liked school, it was boring and repetitive most of the time.   It could be replaced with a semicolon, dash, period or colon and be "correct." Yet to a fair amount of people, the comma seems fine. If it weren't, it wouldn't be found so often in online forums, text messages, emails and so on.  What makes the comma between two sentences an error?


private void validate(String userName, String userPassword){         if((userName == "Admin") && (userPassword == "1234")){             Intent intent = new Intent(MainActivity.this, SecondActivity.class);             startActivity(intent);         } else{             counter --;             Info.setText(userName + " Number of Attempts Left: "+String.valueOf(counter) + " - " + userPassword);             if(counter == 0){                 Login.setEnabled(false);             }         }     }     Whenever i give input as "Admin" and "1234" condition goes to else part. please help me i am beginner in this field.

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


I am using Ubuntu 16.04. I bought a AMD Radeon HD 5450 graphics card, and I need the drivers. The box came with a disk for the drivers, but it is only compatible with Windows. Where can I get the driver for a Radeon HD 5450 graphics card in Ubuntu 16.04?

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?


Tried IE to open 12.04 but it will not.  What to do? How do I open it?

I have downloaded Ubuntu 10.10 and burned the ISO but it will not boot.   I discarded problems with the ISO, as I've downloaded from the official website with no errors, and burned it with no errors. I discarded problems with the burning, as looks like it was recorded with no errors here and later in another computer. I discarded problems with my DVD reader as other cds boots fine.   I'm currently using Ubuntu 9.10, I know I can upgrade via internet, but I have this same problem with my Windows XP cd, so I really would like to discover what's going on here.. My Ubuntu 9.10 cd boots just right, but the new one not.  What else can be? Or what more precise tests can I make to discover where's the problem?   --More info  What happens when I try to boot with the Ubuntu 10.10 cd is that it behaves like there's no bootable cd in the drive. It just don't find the boot on the cd, and start the HD system.  My notebook is an Amazon PC Intel Celeron 1.5 with 2Gb memory, a DVD-RW driver, HD samsung with 260GB.  --update  If you put the media agains the light and see the other side, does that means that it's a bad quality dvd media? (it's a Philips)


how can I remove Evolution and all related packages? I feel like I don't need them.

The looping of Evolution factories slow the system to sudden and lengthy halts. When I access the System  Monitor I can stop the individual processes that cause the problem. These processes are as follows;  evolution-source-registry   notably,     evolution-addressbook-factory  Once evolution-addressbook-factory is stopped the processes are eventually replaced by similarly named processes, but the looping stops. When I connect to Thunderbird it slows substantially. Initially I used evolution mail when running Ubuntu 12.10 but removed it and have been using Thunderbird.  My laptop specs are: Ubuntu 13.04 32-bit 2.0 GHz (dual core, both cores at 2.0 GHz) 1GB RAM After carrying out the recommended procedures for complete removal I recieved a cache read error after removing evolution from the package manager entirely. Re-downloading the packages in the package manager enabled email recognition and produced the error seen in the screenshot.


This may seem silly !. But honestly I have faced this many times during our custom implementation but still unable to find a solution.  Is there a feature either on SFMC UI or using custom API, if we could re-arrange the fields which are already existing in the Data Extension.  To be more clear I just want to bring email_address field as the first field in my DataExtension.   Note:   I am aware that we can clear the records and delete the fields and re-create fields as per our requirement; which would re-arrange the fields. But I want to achieve this without clearing the records.

Is there a way to reorganize the fields/attributes in a data extension?  I've added some extra fields that relate to other fields in that extension.   I haven't found a way to regroup those fields.


I want to install Ubuntu 18.04 alongside Windows 10 using a USB flash drive on an Asus K401UQ laptop - i7 6th gen, 8GB RAM, 1TB HDD + 24GB SSD.  I have left enough unallocated space to install Ubuntu using the - diskmgmt.msc - Windows 10 application.  The problem is I can't find the hard disk when I try to install it as shown in the below screenshots.

I have just got a new laptop, It is running Windows 7 Home Premium.  I have shrunk the windows partition to give me some empty space and now I want to install ubuntu.  From Windows my partitions look like:   So now in the ubuntu live cd If I hit install and go manual the partitioner looks like   So I thought I could just select the empty space and be away laughing, but when I hit it I get


For any natural number $n$ prove that there exist natural numbers $a,b,c$ for which $$n=a^2+b^2-c^2.$$  I think we can have a proof by induction because :   If $n=0$ we choose $a=b=c=0$ or $a=0,b=c$.  If $n=1$ we choose $a=1,b=c$.  Now we need to prove the relationship holds for $n+1$ but I can't prove that.

Prove that any natural number n can be written as $$n=a^2+b^2-c^2$$ where $a,b,c$ are also natural.


For example my folder name is  Test.zip  Test.zip includes various zip folders like te1.zip, te2.zip , te3.zip even te1.zip include various zip folders.    So i need to unzip in linux at once.  Could you please let me know how to do this.

I have numerous zip archives, each of which contains a number of zip archives. What is the best way to recursively extract all files contained within this zip archive and its child zip archives, that aren't zip archives themselves?


I have a situation where a committed file is reviewed by the bug tracker tool and once it reviews the commit message has to change.  So my question is, Is there a way to change the commit message of a file that is already committed into my local git repository?

I wrote the wrong thing in a commit message.  How can I change the message? The commit has not been pushed yet.


I've been trying to create an array which will hold a set of numbers. In this case 10, 33, 55 and 99. What I'm looking for is something flexible to search the array for a variable to see if the number is in it.  var nrArray = [10, 33, 55, 99]; // Any number in this array will decide the function below  if ( 55 = nrArray ) {   // If the number 55 is in the array do the following document.getElementById("demo1").innerHTML = "RUN1"; } else  {             // If the number 55 does not exist in the array do the following document.getElementById("demo2").innerHTML = "RUN2"; }
demo1

demo2
     NOTE 55 in this example will be replaced with a variable that has a number set to it. And this number will vary

What is the most concise and efficient way to find out if a JavaScript array contains a value? This is the only way I know to do it: function contains(a, obj) {     for (var i = 0; i < a.length; i++) {         if (a[i] === obj) {             return true;         }     }     return false; }  Is there a better and more concise way to accomplish this?


What happens if two of my creatures, have triggered abilities, which trigger on attack, in what order it resolves?  For example I have on board  and , and attack with both. Can I scry first put something on the bottom of my library and then exile 3 cards from top of my library, or it resolves at the same time so I scry 3 cards and same 3 cards + 1 additional are exiled?

I had several humans on the battlefield.  On turn three, I played . On turn four, I played . On turn five, during my upkeep, this question came up.  At this point, I need to draw/reveal three cards. If I reveal a human, Descendants' Path will allow me to cast it without paying its mana cost.  So, does it matter when I draw the human?  The static abilities state "at the beginning up your upkeep..." which leads me to believe that those two draws/reveals would happen before my normal draw. If that's the case, does the draw order happen in the same order that I played the enchantments?  In the end, that's how we decided to do it. I drew first for Triumph of Ferocity, then I revealed for Descendants' Path, then I drew for my turn. Did we do it right?


I want to randomize number in each element of array in a variabel. I currently use srand() function. But, with this function i could get a same number in two or more element of array.    the output of my program is         number[0]=6         number[1]=3         number[2]=8         number[3]=3    See, number[1] and number[3] has same value. How to prevent this thing happen?

I'd like to generate unique random numbers between 0 and 1000 that never repeat (i.e. 6 doesn't show up twice), but that doesn't resort to something like an O(N) search of previous values to do it. Is this possible?


Show that $a^4+b^4\geq \frac18$ given that $a+b=1$   $$b=1-a\Rightarrow a^4+b^4=2a^4-4a^3+6a^2-4a+1$$ If we try to find the minimum of a one-variable function,we must solve a 3rd degree equation,on the other hand making perfect squares seems somewhat difficult! Please help.

As in the title. Let $x,y$ be two real numbers such that $x+y=1$. Prove that $x^4+y^4\ge \frac{1}{8}$.  Any hints? Basically, the only method I am aware of is plugging $y=1-x$ into the inequality and investigating the extrema of the function, but I don't think it's the best method. I'm looking for a cleverer way to prove that inequality.


I regularly login to PuTTY and run the following commands to complete a task.  1st Command :     cd/u01/app/oracle/user_projects/domains/COLLECT/EOD/bin_arm   2nd Command :     ./FileUpload.sh   3rd Command :     cd/u01/app/oracle/user_projects/domains/COLLECT/EOD/bin_arm   4th Command :     ./execute_eodarx.sh   How can I automate this with the help of batch or other scripting?  I need to run these commands synchronously. (The next command is to run after the completion of the previous command.)

I have created a .bat file which automatically takes the SSH server (Jump Server) access. Now, I have couple of commands which I would like to hit in that window.  For an ex. (To take root access)  usrun -u root rush   With this command, it'll ask me to enter the password.  So, how can I achieve this entirely through .bat file?


I have a list which I have gotten from json.loads();  myList = [{'label': 'Users', 'host': 'XYZ', 'tags': {'customer': 'XYZ'}, 'data': [[1518756360, 1]]},            {'label': 'Users', 'host': 'ABC', 'tags': {'customer': 'ABC'}, 'data': [[1518756360, 1]]},            {'label': 'Users', 'host': 'EFG', 'tags': {'customer': 'EFG'}, 'data': [[1518756360, 1]]}]    Is there a way to sort this list based of host key so that it becomes like this?  mySortedList = [{'label': 'Users', 'host': 'ABC', 'tags': {'customer': 'ABC'}, 'data': [[1518756360, 1]]},                  {'label': 'Users', 'host': 'EFG', 'tags': {'customer': 'EFG'}, 'data': [[1518756360, 1]]},                  {'label': 'Users', 'host': 'XYZ', 'tags': {'customer': 'XYZ'}, 'data': [[1518756360, 1]]}]    I tried myList.sort() and myList.sort(key='host') but it didn't work.

I have a list of dictionaries and want each item to be sorted by a specific value. Take into consideration the list: [{'name':'Homer', 'age':39}, {'name':'Bart', 'age':10}]  When sorted by name, it should become: [{'name':'Bart', 'age':10}, {'name':'Homer', 'age':39}]


Consider a square with the side of length n and $(n+1)^2$ points inside it. Show that we can choose 3 of them to determine a triangle (possibly degenerate) of area at most $\frac{1}{2}$. I think that I know how to solve the problem for the cases $n=1$ and $n=2$: For $n=1$ we can easily prove that the triangle formed by those 3 points has the area at most $\frac{1}{2}$,like here: For $n=2$ we can divide the square into 4 smaller squares (by uniting the midpoints of the opposite sides),each of them with the length of the side equal to 1.By pigeonhole priciple we know that at least one of those squares contains at least 3 of the 9 points inside it.From here we can use the same proof from the case $n=1$ to prove that those 3 points determine a triangle of area at most $\frac{1}{2}$ This idea doesn't work for the other cases because we would need $2n^2+1$ points instead of $(n+1)^2$ Can you help me please with the other cases? Source:book:Combinatorics Advances,by Charles J. Colbourn

Consider a square of sidelength $n$ and $ (n+1)^{2} $ interior points. Prove that we can choose 3 of these points so that they determine a triangle (eventually degenerated) of area at most 1/2.  I couldn't get started on this. Any ideas?


Following fails to execute  create table product_instance (   "ID" number(19,0),   constraint pro_instance_pk primary key ("id") )   giving the output  SQL Error: ORA-00904: "id": invalid identifier 00904. 00000 -  "%s: invalid identifier"   However the changing "id" to "ID" works fine  create table product_instance (   "ID" number(19,0),   constraint pro_instance_pk primary key ("ID") )   Following also works fine  create table product_instance (   ID number(19,0),   constraint pro_instance_pk primary key (id) )   Appreciate if someone could answer the effect of specifying "ID" instead of just id in the DDL statements. Is oracle case sensitive or insensitive

I thought that the quotation mark (") was simply a type of grouping marker but I'm debugging some NHibernate code and notice that while  SELECT * FROM site WHERE site_id = 3;   Works fine  SELECT * FROM "site" WHERE site_id = 3;   fails with a table or view does not exist error.  What gives?


What's the difference between:  int i = 0; foo(i);  int foo(int i){ ... }   and:  int i = 0; foo(&i);  int foo(int *iPtr){ ... }   I mean, is passing by reference faster and better for memory/performance? Why should I use reference?  Also, my professor said that when we pass by value we are actually passing for reference.. so what's the real difference between them?  I thought that pointers and passing by reference were used to optimize performance and memory..

What is the difference between    a parameter passed by reference a parameter passed by value?   Could you give me some examples, please?


I would like to have a command \simrightarrow, that is, a \rightarrow with a \sim over it. Stealing  from @egreg, I got:  \documentclass{article}  \usepackage{unicode-math}    \newcommand{\simrightarrow}{\mathrel{\ooalign{      $\to$\cr      \hidewidth\raise.3em\hbox{$\sim\mkern3mu$}\cr     }   } }   \begin{document} \( M \simrightarrow N \) \end{document}   However, the tilde is still too big. How can I scale it down?

I want to make a latex symbol that contains a resized math symbol using \scriptscriptsize. However, when the scope containing the symbol is subject to a font resize, the \scriptscriptsize-ed symbol is not resized appropriately.    Please see this image, and note that the rightarrow size doesn't change as much as the tilde:   Here is a snippet that demonstates the problem:  \documentclass{article} \newcommand{\isoeq}{  \kern-0em\mathrel{\raisebox{0.13em}{${\sim}$}} \kern-0.75em\mathrel{\raisebox{-0.13em}{${\scriptscriptstyle \to}$}}   }  \begin{document} {\normalsize $A \isoeq B$}, \quad {\Large $A \isoeq B$} \end{document}   Could you explain how this is done correctly such that the rightarrow $\to$ above respects resizing.


I have a file that contains any of the following number format  12.456.7890 12-456-7890     123.456.7890 (123)456.7890 (123).456.7890 123-456-7890 (123)-456-7890 (123)456-7890   Is it possible to use regex substitution so that the final output number will always be on a format (123)456-7890 or (12)456-7890

I'm trying to put together a comprehensive regex to validate phone numbers. Ideally it would handle international formats, but it must handle US formats, including the following:   1-234-567-8901 1-234-567-8901 x1234 1-234-567-8901 ext1234 1 (234) 567-8901 1.234.567.8901 1/234/567/8901 12345678901   I'll answer with my current attempt, but I'm hoping somebody has something better and/or more elegant.


This is the program in question:  namespace TestStuff {     public class Test     {         public int x;     }     class Program     {         static void Main(string[] args)         {             Test firstClass = new Test();             firstClass.x = 5;             Test secondClass = firstClass;             firstClass.x = 6;             Console.WriteLine(secondClass.x);          }     } }   The output of this program is 6, I assume this is because Test secondClass = firstClass;, makes secondClass point to firstClass instead of making a copy of firstClass. If i want to make secondClass a copy of firstClass, how would I go about that ?

I want to do something like:  MyObject myObj = GetMyObj(); // Create and fill a new object MyObject newObj = myObj.Clone();   And then make changes to the new object that are not reflected in the original object.  I don't often need this functionality, so when it's been necessary, I've resorted to creating a new object and then copying each property individually, but it always leaves me with the feeling that there is a better or more elegant way of handling the situation.  How can I clone or deep copy an object so that the cloned object can be modified without any changes being reflected in the original object?


I can't seem to find a full proof that for every infinite cardinal $κ$, $k^2 = k$. Does anyone have one they could share?

This about the famous article   Zermelo, E., Beweis, daß jede Menge wohlgeordnet werden kann, Math. Ann. 59 (4), 514–516 (1904),   available . Edit:  (OCR'ed, may be behind a paywall)  An English translation can be found in the  Collected Works/Gesammelte Werke by Ernst Zermelo. Alternative source: the  From Frege to Gödel: a source book in mathematical logic, 1879-1931, by Jean Van Heijenoort.  [See also this interesting  by Dan Grayson.]  I don't understand the paragraph on the last page whose English translation is     Accordingly, to every covering $\gamma$ there corresponds a definite well-ordering of the set $M$, even if the well-orderings that correspond to two distinct coverings are not always themselves distinct. There must at any rate exist at least one such well-ordering, and every set for which the totality of subsets, and so on, is meaningful may be regarded as well-ordered and its cardinality as an "aleph". It therefore follows that, for every transfinite cardinality,    $$\mathfrak m=2\mathfrak m=\aleph_0\,\mathfrak m=\mathfrak m^2,\mbox{and so forth;}$$   and any two sets are "comparable"; that is, one of them can always be mapped one-to-one onto the other or one of its parts.   It seems to me Zermelo says that the fact that any set can be well-ordered immediately implies that any infinite cardinal equals its square. Is this interpretation correct? If it is, what is the argument?  Side question: What is, in a nutshell, the history of the statement that any infinite cardinal equals its square? Where was it stated for the first time? Where was it proved for the first time? (In a similar vein: where was the comparability of any two cardinal numbers proved for the first time?)    Edit: German original of the passage in question:     Somit entspricht jeder Belegung $\gamma$ eine ganz bestimmte Wohlordnung der Menge $M$, wenn auch nicht zwei verschiedenen Belegungen immer verschiedene. Jedenfalls muß es mindestens eine solche Wohlordnung geben, und jede Menge, für welche die Gesamtheit der Teilmengen usw. einen Sinn hat, darf als eine wohlgeordnete, ihre Mächtigkeit als ein „Alef“ betrachtet werden. So folgt also für jede transfinite Mächtigkeit   $$\mathfrak m=2\mathfrak m=\aleph_0\,\mathfrak m=\mathfrak m^2\text{ usw.,}$$   und je zwei Mengen sind miteinander „vergleichbar“, d. h. es ist immer die eine ein-eindeutig abbildbar auf die andere oder einen ihrer Teile.


One of my concerns about myself going for a moderator position in an election is that one of the general questions that are gathered as very common questions asked every election is     In what way do you feel that being a moderator will make you more effective as opposed to simply reaching 10k or 20k rep?     Now sure this question may not actually be asked but when I try to evaluate on whether I can be a good mod I look over all the questions and see if I can answer them all. With the above question I just wouldn't be able to give an answer. I know Mods have access to more tools that what those with high rep have access to but I don't know what these tools are or even how they work.  I want to change that. I would like to know where someone can read up on the tools Mods have access to as opposed to what high rep users have access to.

As an alternative to the other FAQ format being fleshed out here on Meta Stack Exchange, I'd like to propose something far more terse that covers the bare essential mechanics of being a moderator.   Feel free to add more questions, but keep them short: this isn't the place to get into complex moderation issues, but for an executive summary of what it is to be a moderator.  To add a new section, create a new answer and link to it in the index below.  Index:               See also:


You are given a string with length 10. Its characters are 0,1,2,...,9 (every number are in the string). How many permutations of the string such that the absolute difference of every two neighboring number are greater than 1?  ex: 1425379680 is correct 1234567890 is wrong because 1 and 2's difference are 1, 2 and 3's difference are 1, etc.  Note: Because it is a string, 0 as a starting number is okay.  *Sorry if my english is bad.

In how many ways can the natural numbers from 1 to 10 be arranged so that no two consecutive numbers are adjacent to each other, and how is the formula arrived at?


I want to make a Minecraft server with mods in 1.11 but do the players need mods as well because I heard from people that they just need forge.

I'm wondering if I could play Minecraft with my friend. A modded Minecraft, only myself with mods and him without mods.  Is it possible?


In my text, for the question, The dog along with his master ___ for a walk., the answer is marked as "are going" And for another question, The dog, along with his master, ______ for a walk., the answer is marked as "is going" I think both sentences are the same and that the usage of comma in the second sentence is unnecessary. Since 'along with' is not a coordinating conjunction, the part before it, is to be considered subject. So I feel "is going" should be the answer. Am I wrong? Please clarify

I was interested in the following sentence which appeared in a   in The Washington Post, Politics, (WHO RUNS GOV).     She, along with Mark Childress, were set to be Daschle's deputies at   the White House before he stepped down.   Can someone clarify if the fragment "She, along with Mark Childress, were set to" is ungrammatical, as I think it is?  I would reword were with was because I think that the subject of the sentence - obviously, in grammatical terms - is "She", not "She" and "Mark Childress", but I'm not sure on this correction.  More precisely, I'm not so sure that "She, along with Mark Childress" is equivalent to She and Mark Childress with regard to the effects on the grammatical numbers.


Evaluate $$I=\int \frac{dx}{(x^2-x+1)\sqrt{x^2+x+1}}$$  My book gave the substitution for $$\int \frac{dx}{P\sqrt{Q}}$$ as  $\frac{Q}{P}=t^2$ when $P$ and $Q$ are quadratic expressions  So accordingly i used     $$\frac{x^2+x+1}{x^2-x+1}=t^2 \tag{1}$$ we get  $$\frac{(1-x^2) \, dx}{(x^2-x+1)^2}=t \,dt$$  Then  $$I=\int \frac{\sqrt{x^2-x+1}\:dt}{1-x^2}$$  By Componendo Dividendo in $(1)$ we get  $$\frac{x^2+1}{x}=\frac{t^2+1}{t^2-1}$$  But how to express integrand purely in terms of $t$?

Compute the indefinite integral   $$ \int\frac{dx}{(x^2-x+1)\sqrt{x^2+x+1}} $$   My Attempt:  $$ \int\frac{dx}{(x^2-x+1)\sqrt{x^2+x+1}}=\int\frac{1}{(x^2-x+1)^{3/2}.\sqrt{\dfrac{x^2+x+1}{x^2-x+1}}}\,dx $$  Now define $t$ such that $t^2=\dfrac{x^2+x+1}{x^2-x+1}$ to get  $$ \begin{align} 2t\,dt &= \frac{(x^2-x+1)(2x+1)-(x^2+x+1)\cdot (2x-1)}{(x^2-x+1)^2}\,dx\\ 2tdt &= \frac{-4x^2+2x+2}{(x^2-x+1)^2}dx \end{align} $$  I don't know how to proceed from here.


So there's a question in the close review queue.  Its 0 score and looks to be ok at the top, but its long and I'm scrolling down to see if there's a multi-part question or something else that is too broad being asked as I get to the bottom.  And then BLAM in big red text, it is obvious this is an audit.  There's a bounty on the question.     Yes, this is a screen shot after the review, but it was there in the audit too.  You can't place a close vote on a bountied question and so there's no way for this to be in the queue any other way than an audit.  Looks good without actually reading the actual text of the question and I pass the audit.  The feature request:  Don't show bounties on known good questions when using them as audits.  Yes, I believe a good audit system requires you to read the text rather than going off of other hints about the question.

I had  in the close review queue. It clearly shows the question with a bounty, but bountied questions cannot be closed. Either bounty questions shouldn't be used as audits, or don't display the bounty notice.    This is the same problem , except it's happening in the close queue rather than reopen.


I have written a bash script which does the following:   Ask user to input the path of the directory containing all CSVs. Run a C++ script that does takes each CSV and do some processing on it   echo "Enter the path where all the CSVs are stored" read varname    The problem is now when I do $varname and pass it to my C++ code, it's not getting interpreted as a string. Only the first value is being passed which makes sense but I am unable to figure out how to send the varname as a single string. For example, if I enter path_to_CSVs/*.csv, then I want to pass this value in this format "path_to_CSVs/*.csv"to my C++ program.  I am not an expert in bash scripting, so can someone please help?

For example:  me$ FOO="BAR * BAR" me$ echo $FOO BAR file1 file2 file3 file4 BAR   and using the \ escape character:  me$ FOO="BAR \* BAR" me$ echo $FOO BAR \* BAR   I'm obviously doing something stupid.  How do I get the output BAR * BAR?


Previously, I was able to play music on iTunes without a Wi-Fi connection. Now, I get an error message and my music will not play. WHY?  How can I play my music through iTunes without a Wi-Fi connection?

Since the last update, iTunes is unusable for me on my iMac, because with every song change it shows a "Could not connect to the iTunes Store" error message. My network at work does not allow access to the iTunes store, but that is ok. I just want to listen to my local music connection there. I have disabled the iTunes Store in the parental settings completely, but still, the error pops up with each and every song change. Any idea how to prevent iTunes from showing this popup?  There are two major annoyances here in iTunes imho a) iTunes tries to access the store even if it is disabled completely in the settings and you're signed out b) The error messages "staple" on top of each other, so iTunes diplays the same error 1000 times and you have to click them all away. This reminds me of Windows 95 times.


I've heard the term "onto" several times but still not sure what it means or implies.  It's often said along with the function is "one-to-one".

I thought you have to say a mapping is onto something... like, you don't say, "the book is on the top of"...  Our book starts out by saying "a mapping is said to be onto R^m", but thereafter, it just says "the mapping is onto", without saying onto what. Is that simply the author's version of being too lazy to write the codomain (sorry for saying something negative, but that's what it looks like to me at the moment), or does it have a different meaning?


I know that if $X,Y$ are independent, then $E(XY) = E(X)E(Y)$ holds. But the reverse is not true. I'd like to know that are there any examples to show the fact?

Is there a simple example showing that given $X,Y$ uncorrelated   (covariance is zero), $X,Y$ are not independent?   I have looked up two references, however, I am dissatisfied with both.   In Reference $1$, $X,Y$ are assumed to be independent uniform RVs from $(0,1)$, construct $Z = X+Y, W = X - Y$, then the claim is that $Z,W$ is uncorrelated but not independent. Unfortunately, finding the PDF of $Z,W$ is not trivial. In Reference $2$, $\phi$ is assumed to be uniform RV from $(0,    2\pi)$, and construct $X = \cos(\phi)$, $Y = \sin(\phi)$. Then the claim is that $X,Y$ are uncorrelated but not independent. Unfortunately, the PDFs of $X,Y$ takes on the form of rarely mentioned arcsine distribution.   I just wish to have an example at hand where I can whip out to show that uncorrelated does not necessarily implies independent. Is this do-able?


I have a Linux laptop and I want to set it up as an alarm clock (used to have it on my Mac years ago).  The problem is if I shutdown my laptop the night before, the alarm will not work.  Is there a way to set up time schedules in Linux when the machine should power on? Or do I have to do this in BIOS/UEFI...somehow?  It should also wake up from sleep or hibernation.  EDIT: The duplicate question talks about waking up the machine from sleep or hibernation. I want to turn it on from a complete shutdown. I know this can be done on Macs.

I know that there are many ways to auto-shutdown, but I'm concerned about auto turn-on. Is there a command or a small piece of software to turn on the system at given time?


is it possible to move steam games in your library to your steam gift inventory? i would like to trade my games for keys/metal/unusual's for tf2 but i can't figure out how to do so. Is it even possible? please help :P

I understand that once a game is in the library it cannot be removed, only hidden.  My question is, can I gift an uninstalled copy of a game to a friend?  I understand that this may be impossible due to legal issues, and that once a game is in the library it stays.


I came across this answer to another stack exchange question and wondered about how true the claim was.   It starts with a disclaimer that claims that      A perfect vacuum is impossible   Now I know that perfect absolute zero is a theoretical impossibility because of many theories regarding quantum physics make it so, namely it's impossible to know the position and momentum of atoms at the same time: If they weren't moving you'd know where they were and that they had no momentum. So making something totally absolute zero is impossible. However is there a similar (or even dissimilar) theoretical impossibility regarding a perfect vacuum. If there were no atoms in the space then you'd have nothing to know the position and momentum of.  Because of this question:  (and the fact the answers are a little ambiguous anyway) I'm more loosely defining a vacuum as a space that has absolutely no complete atoms or perhaps, if it makes it actually practical to answer, molecules in it at all, ignoring zero point energy, radiation etc.  Lets also assume that the space is defined by a solid container. One that hypothetically doesn't degrade.  I'm not saying that it would be easy, ensuring no residual atoms were present would be practically impossible I'm sure but I see no reason why it would be theoretically impossible. Granted I'm not in any kind of physics related field so my knowledge is rudimentary at best.

In  someone mentioned that it couldn't happen. Why not?   For example I asked about the speed an object would have to move at sea level to create a vacuum behind it; in the comments someone asked what I meant by vacuum because there couldn't be a perfect vacuum.


I came across an odd thing. I searched "nice" in Lexico and see what it says about its origin: Middle English (in the sense ‘stupid’): from Old French, from Latin nescius ‘ignorant’, from nescire ‘not know’. Other early senses included ‘coy, reserved’, giving rise to ‘fastidious, scrupulous’: this led both to the sense ‘fine, subtle’ (regarded by some as the ‘correct’ sense), and to the main current senses.    How did it take the meaning of "Giving pleasure or satisfaction; pleasant or attractive"?

The word "nice" tends to be used in rather a wishy-washy sense these days. In general use it tends to mean anything that is satisfactory.  But what are the origins of this word? What did it originally mean? Why has the meaning changed so much through the years?