I would like to have Ubuntu set its self up when it boots, as Windows does. There is a laptop that I am giving to a kid on Christmas with a dead Hard Drive, and I would like to prepare it for him. The laptop is not currently in my possession, but the hard drive is. I can do the troubleshooting for him if drivers are necessary later, but I would like the Hard Drive to have Ubuntu installed on it and just needing configuration with users and passwords. I have seen something like what I want before, but it was by a wubi install, and it did not prompt for a username and password to create.  So, if that confused you, my goal is to have the computer when it boots to prompt for a username and password to create.  I have an idea that could work, but not as well as desired. Currently, I have a live CD of Ubuntu 13.10, and I was planning on putting the Hard Drive in my laptop as its only, booting from a live usb, wiping the Hard Drive, creating a 512 Mb partition leaving the rest blank, and burning a live CD to that Hard drive to boot from. So, I would want to tweak the live HD's install to not allow the option for try Ubuntu.  I would prefer this to be on 13.10 because I have been using it flawlessly for the past month or two, and it has many features he would like. I am ok if it is only possible on 12.04.  So, to present all my Questions   Can I install Ubuntu without a user, but prompt for one on First boot Or, can I install Ubuntu from a Hard Drive as a live CD to itself   If one of them gets answered, but not the other please answer the other one if you can for anyone else looking at this post. I will be trying the second method tonight possibly and answer below.

I would like to pre-install Ubuntu on a computer for someone. I may want to customize it for them, but in the end they need to be able to choose a username, password, etc. when they first boot it up. (Also called an OEM install).  How do I do this?


I have a B1/B2 US visa valid from 18 Nov'14 - 16 Nov'19, however, have not visited the US during this period and do not foresee visiting by the 16th November this year.  There were several changes in my circumstances (family, finances, etc.) over the past few years that did not enable me to visit. I wish to extend my visa for future visits, hopefully, next summer. Will this be ok? Kindly advise. Thank you.

I have a valid 5 years B1/B2 visa that was issued about 4 years ago.  I never used it as I intended to travel to work in a specific project that was cancelled.  Now, There is a similar project scheduled next year. So, I have to renew the visa as it will expire before the project's start date.  Can I renew the visa although it wasn't used (I never traveled to US) ?


A MySQL database contains two tables with a one-to-many relationship: One user can have many settings:  Users: id    username    password --------------------------  1    Bob         123  2    Alice       abc  ...   Settings: id   user_id   key     value -----------------------------  1   1         color   blue   // Bobs settings...  2   1         theme   xy  3   1         size    5  4   2         size    5      // Alices settings...   Problem: How to find all users with color == blue AND size == 5?  Using a LEFT JOIN it is no problem to find users with one property:  SELECT users.id FROM users LEFT JOIN settings ON users.id = settings.user_id WHERE settings.key = 'color' AND settings.value = 'blue'   However, this does not work when searching for two settings at a time?   Is it possible to solve this with a single statement? What is the most efficient way to query this data?

This is a very basic query I can't figure out....  Let's say I have a two column table like this:  userid  |  roleid --------|--------    1    |    1    1    |    2    1    |    3    2    |    1   I want to get all distinct userids that have roleids 1, 2 AND 3.  Using the above example, the only result I want returned is userid 1.  How do I do this?


I downloaded a 3d motorbike from unity asset store. But its facing forward along -x-axis. All the parts are separate as children of a main object. I would like to fix it so that its facing along z-axis by default.  How can this be achieved in blender?

I was doing fine with importing an obj I made in Marvelous Designer into Blender for rigging.  The dress would settle nicely on my SL avi.    Now when I import the object; it is perpendicular to my avi and I have spent a week trying to figure out what I did...  Is there a keystroke or setting that I need to make sure is correct so that my dress fits my avatar again?


I am working on a probability problem and here is what I have so far.     A stick with fixed length $L$ is broken at two points randomly.  Find the probability that the resulting three shorter sticks will form a triangle.   I let $X_1$ and $X_2$ be points on the stick , and without loss of generality I assume $0 < x_1 < x_2 < L$.  Because the points are chosen randomly I let $X_1 \sim U(0,L)$ and $X_2 | X_1 \sim U(x_1,L)$.  Under this assumption I know that   $$f_{X_1}(x_1) = \frac{1}{L}, \quad f_{X_2|X_1}(x_2)=\frac{1}{L-x_1}$$  and   $$f_{X_1,X_2}(x_1,x_2)=\frac{1}{L}\frac{1}{L-x_1}$$  I also want to use the triangle inequality which simplifies to  $$x_2 > \frac{L}{2} > x_2-x_1, \quad \frac{L}{2} > x_1$$  I know how to find these individual probabilities but I do not know how to combine them to get the answer. . .  May I have some assistance?

I have a 1-meter long stick. Let $x,y$ be i.i.d with uniform ([0,1]), representing the cut in the stick. What is the probability that the 3 segment form a triangle?  Attempt:  Pr{triangle} = Pr(triangle | x < y) Pr(x < y) + Pr(triangle | x > y) Pr( x > y).   Let's look at the first term. Pr(triangle | x < y) requires:  1) x + y-x > 1-y  2) x + 1 -y > y-x  3) y-x + 1-y > x  Which is equivalent as   1.y >0.5,  2. x < 0.5  3. y - x < 0.5.  This is a triangle which has the area of 1/8.   Due to symmetry, Pr(triangle | x > y) = 1/8.   Now. Pr{triangle} = Pr(triangle | x < y) Pr(x < y) + Pr(triangle | x > y) Pr( x > y)   = 1/8 *0.5 + 1/8 *0.5 = 1/8 $\neq$ 1/4 (as posted )  Confusion: Did I do something wrong?


On my HP Microserver (Ubuntu 16.04 LTS) I updated an hour ago to the latest kernel (4.4.0-108-generic). After that the system won't start. I 'Grubbed' into 4.4.0-104 and it boots without problems. Anyone else have the same experience?  I noticed later that someone else has already mentioned this (i.e. possibly the same problem) in . My apologies.

Today I got what I presume was the update that should take care of Spectre and Meltdown. That didn't go very well. What do I do now? See screen photo.    I can't boot the 4.4.0-108-generic kernel because of a kernel panic. I'm running 16.04 on an Intel Core i5-4670K CPU @ 3.40GHz × 4.


I have accidentally format, repartitioned and installed the MacOS on SSD installed on my Macbook Pro months ago, and now I just realized i loss my very important data during that, So i need the recommendation for the best recovery software which will be Compatible/Trustable by Apple which help me to recover that data.

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


I've recently discovered snapsort.com and use it to compare other cameras with the one I own. When comparing Pentax k10D with the K-x model I learned that the K-x has a CMOS sensor and that     CMOS-family sensors often produce better quality images   The  for that is     [CMOS sensors] also permit more integrated designs which can cut down on noise gain and provide the opportunity for a cleaner image.   which I take to mean that lower noise is due to better IC designs made possible with CMOS, not the sensor type itself.   Is this a meaningful  distinction? All things being equal, do CMOS sensor produce better quality images that CCD?

I keep reading articles about CCD vs CMOS image sensors. What is the difference between these two types? What exactly do these sensors do in terms of photography?  Is a CCD-based camera going to be able to compete in the future? If I buy one, can I count on using it for some years or would it be better to upgrade to a camera with a CMOS based sensor?


I'm looking to convert the string name of a class to a class, then pass that class name to a method which accepts <T>:  var objectList = _reader.GetObjects<MyClassName>();   and the method I'm calling is:  public List<T> GetObjects<T>() where T:new() {  }   Do you know how this can be done? I've tried:  var type = Type.GetType(MyClassName); var yourObject = Activator.CreateInstance(type);  var objectList = _reader.GetObjects<yourObject>();   but that doesn't work, I get the error message 'yourObject is a variable but is used like a type'  It does work if I use an actual class name.  Any ideas?

What's the best way to call a generic method when the type parameter isn't known at compile time, but instead is obtained dynamically at runtime?  Consider the following sample code - inside the Example() method, what's the most concise way to invoke GenericMethod<T>() using the Type stored in the myType variable?  public class Sample {     public void Example(string typeName)     {         Type myType = FindType(typeName);          // What goes here to call GenericMethod<T>()?         GenericMethod<myType>(); // This doesn't work          // What changes to call StaticMethod<T>()?         Sample.StaticMethod<myType>(); // This also doesn't work     }      public void GenericMethod<T>()     {         // ...     }      public static void StaticMethod<T>()     {         //...     } }


I am wondering how i can center my image upload form.
Your browser doesn't support upload.
   All the other elements like buttons are centered with:  .jumbotron { margin: 60px 0; text-align: center; }

How can I horizontally center a
 within another
 using CSS?

Foo foo


Currently I'm unable to upload an image to anywhere on site: e.g. posts or chat.                Is this problem with Imgur?

I just wrote a question before this one and had trouble uploading a screenshot. The drop your image dialog throws no warning or error, but after uploading it won't show.  I also noticed that other questions won't load their images. Could this be some issue with imgur or similar?  Example:     When opening the image in a separate tab, Chrome gives a "too many redirects" error:    This might be linked to


In the word "afternoon tea"(the tea that is served in afternoon) the word 'afternoon' is an uncountable noun as OALD shows. In the word "English countryside"(the countryside that is in England) the word 'English' becomes adjective. But why? I can't see the difference in the work these words do. Other examples are "egg noodles", crocodile shoes", "sports car" and "double bed", "favourite movies", "paper tiger". (Interestingly OALD does not count "paper" as adjective.) Can somebody kindly explain me please. Thank you!

What determines whether something is a "noun adjunct" or just a garden-variety adjective?  Does it matter in any meaningful way?  Here is my hypothesis, but I can't find any authoritative source to back it up. I'm hoping someone here can weigh in more definitively.   Classification of noun adjuncts is based subjectively on whether the word is in "common usage" as a noun.  "Book" and "chicken" are commonly nouns and would be considered noun adjuncts in "book collector" and "chicken soup"; "yellow", not so much. Noun adjuncts may share some common qualities that differentiate them from other adjectives (like not being able to be inflected into superlative forms... one can't be a "book-est collector").  But they are still fundamentally adjectives and may even appear in the dictionary as such if the adjectival usage is common enough.   What I've found so far...  Wikipedia defines a "" as:     an optional noun that modifies another noun; it is a noun functioning as an adjective.   But English words are not decreed to be nouns or adjectives by some higher authority.  So it seems strange that one can prescriptively conclude that something "is a noun" in the first place, let alone extrapolate that it "is a noun functioning as an adjective".  The wiki article cites "chicken soup" as an example of a noun adjunct, but at least  gives a definition for "chicken" as:     adj. (of food) containing, made from, or having the flavor of chicken   So it seems that there are some differing points of view on how to categorize these words.  This question was spawned from some discussion in ,  and .


I am seeing a huge number of connections from a single IP.  # netstat -alpn | grep :80 | grep 92.98.64.103  tcp        0      0 my.ip.address.x:80            92.98.64.103:45629          TIME_WAIT   -                    tcp        0      0 my.ip.address.x:80            92.98.64.103:44288          TIME_WAIT   -                    tcp        0      0 my.ip.address.x:80            92.98.64.103:48783          TIME_WAIT   -                    tcp        0      0 my.ip.address.x:80            92.98.64.103:40531          TIME_WAIT   -                    tcp        0      0 my.ip.address.x:80            92.98.64.103:54094          TIME_WAIT   -                    tcp        0      0 my.ip.address.x:80            92.98.64.103:47394          TIME_WAIT   -                    tcp        0      0 my.ip.address.x:80            92.98.64.103:43495          TIME_WAIT   -                    tcp        0      0 my.ip.address.x:80            92.98.64.103:55429          TIME_WAIT   -                    tcp        0      0 my.ip.address.x:80            92.98.64.103:42993          TIME_WAIT   -                    tcp        0      0 my.ip.address.x:80            92.98.64.103:49542          TIME_WAIT   -                    tcp        0      0 my.ip.address.x:80            92.98.64.103:54812          TIME_WAIT   -    There are 419 such lines. But I see only 1 request from 92.98.64.103 in my access log. Is this DoS attack?  UPDATE -  419 Connections are from a single IP. There are several such IPs with over 100 connections.  The normal RAM usage of my server is around 2-3 GB. But at that time it was using 15GB RAM.  root@mars [~]# netstat -alpn | grep ':80 .*TIME_WAIT' | wc -l 6728   UPDATE 2 - TIME_WAIT increased to over 10000 in a few seconds  root@mars [~]# netstat -nat | awk '{print $6}' | sort | uniq -c | sort -n       1 established)       1 Foreign       4 CLOSE_WAIT       9 FIN_WAIT2      34 LAST_ACK      39 SYN_RECV      44 LISTEN      45 CLOSING      68 FIN_WAIT1     128 ESTABLISHED   10261 TIME_WAIT   But the web server is loading fine without any problem.


I'm building a portable speaker using a PAM8403 amp, 3.7v battery, and a battery charging module, all powered by USB input. What I want to do is be able to switch between   1) charging the battery from USB input  2) Power amp just from 3.7v battery.  3) power amp just from USB input(So when it is plugged into the wall it runs 5v. to the amp and gives it more power than when running off the battery).  I can't figure out how to do this without using switch for the battery, the power input, and to turn it all on and off. so many switches would be very user friendly. Is there a way to do this with less switches?

I am doing a project where my electronics runs on 5V which I wanted to power from a 7.2v lipo regulated down to that voltage. I'd really like to include the opportunity to charge the lipo without removing it from the project. What kind of circuit/components do I need to do it properly?  Say, would putting a battery charging ic at the battery's terminals in parallel to my system be enough to achieve what I need?


I need to make the code below disregard any case sensitivity Here's the code:  sentence=str(input("Enter sentence") words=sentence.split() uword=input("enter word from sentence") if uword in words:     print("Word is in sentence") else:     print("Word isn't in sentence")   For example if I inputted the sentence "Hello World" as the sentence variable and then inputted "hello" as the uword variable the code should recognise that hello and Hello are the same and print (" Your word is in the sentence")

How can I do case insensitive string comparison in Python?  I would like to encapsulate comparison of a regular strings to a repository string using in a very simple and Pythonic way. I also would like to have ability to look up values in a dict hashed by strings using regular python strings.


What is the intuition behind the probability density function of a continuous random variable? Integrating it within two points provides the probability that is associated between two points, but if you plug a single value into $f(X=x)$, it outputs a value. What is the intuitive understanding of this value for a given x?   For example, in the above image, the value of the red curve at x=0 is 0.4. How can 0.4 be interpreted?

Conceptually I grasp the meaning of the phrase "the total area underneath a PDF is 1". It should mean that the chances of the outcome being in the total interval of possibilities is 100%.  But I cannot really understand it from a "geometric" point of view. If, for instance, in a PDF the x-axis represents length, would the total area underneath the curve not become larger if x was measured in mm rather than km?  I always try to picture how the area underneath the curve would look if the function were flattened to a straight line. Would the height (position on the y-axis) of that line be the same for any PDF,or would it have a value contingent on the interval on the x-axis for which the function is defined?


I would like to compute the value of this series:  \begin{equation*} \sum_{n = 0}^{+ \infty} n . e^{- \alpha n} \end{equation*}  Where $\alpha$ is a constant.

I'm trying to compute the infinite series $\sum_{n=0}^{\infty} ne^{-n}$.  I know the answer is $e/(e-1)^2$, but I don't understand how to find this result.  Thanks for the help!


I'm running a samsung chromebook xe500c21 with a intel atom inside and was wondering the best way to get ubuntu on it? Or remix os for that matter on it? Without using the crouton.

I have installed Ubuntu 13.04 on my desktop (runs like a charm). Then I used Crouton to install Ubuntu 12. 04 on my chromebook samsung (ARM). It also works quite well.  Here comes my question. Can we have a true Ubuntu (preferably 13.04) on my ARM chromebook?  It seems that the Crouton/Ubuntu is not 100% the real thing.  The best option would be to have the full Ubuntu 13.04 and remove the Chrome OS.


When Yoda said "there is another," I always figured it had to do with Darth Vader. The ending makes much more sense that way.   The counter-argument that I keep seeing is that Yoda was specifically referring to Leia. I don't think that this is necessarily true.   To me it seems like this: Yoda just didn't know who the other hope was. He felt a really strong force, and felt that it had some good in it. It doesn't mean he knew whom it belonged to. He was a Jedi master, not a prophet. Even if it were powerful enough to belong to a Skywalker, we can't really blame Yoda for not considering Vader a candidate. Seems to me that when he said "there is another," he meant exactly that, and nothing more: there is another hope.  Again: I don't think Yoda necessarily knew it was Vader.  But I don't think he was sure about it being Leia either.  Ben believes Yoda meant Leia, but there is a couple of reasons to think that he and Yoda differed on that.  In response to "That boy is our last hope," Yoda's cryptic words are "No. There is another."  It is an odd thing to say to Ben, who was well aware that Padme had two children.  Yoda would have just said "His sister there always is."  Ben's belief that Yoda meant Leia is mistaken, but understandable: Vader was quite a bad guy, and Yoda had reservations about Anakin from the get-go.  It seems to me that the viewer is being intentionally misled in order to make Vader's change of heart that much more impactful.  The plot itself also suggests that Vader was the real other last hope.  Leia was very helpful, but her help was a bit more general, not reflecting a "last hope" role.  In addition, her help had very little to do with her being a Skywalker.  She could have done all the stuff she did being a Dolan, Smith, or Schwartzbraum.  Her being Luke's sister benefited Han Solo, but that's about it.  However, Darth Vader very much played the role of "another last hope."  When Luke was beaten and the need for "another" became real, it was Vader's decision to turn from the dark side that made the difference; he very much delivered on his role as "another."  And he did it precisely because he was Luke's father.  The last hope did end up resting on a Skywalker - not because of his powers, but because of his love for his son.  It makes a lot more sense than Leia's rather unfulfilled "last hope" role.

In the original trilogy Yoda refers to another hope:     Obi-Wan: "That boy is our last hope."   Yoda: "No...there is another..."   The assumption being after seeing Return of the Jedi (Episode VI) that the other was Leia.  If, however, you consider the prequel trilogy canon, then this assumption depends greatly on your point of view*. Obi Wan knows about Leia (and for unknown reasons has discounted her as a hope), so Yoda must be referring to someone or something else.  Is there any canonical source as to what Yoda meant, or was uncle George setting us up for Episode VII?  *as a wise man once said      you will find that many of the truths we cling to depend greatly on   our own point of view.   Just to add a bit of clarity: I was thinking about who Yoda was referring to when he was talking to Obi-Wan. When talking to Luke, it is obvious that Leia is the other (as he talks about a 'Skywalker'). It is not so obvious (after watching the prequel trilogy) that he means it when talking to Obi-Wan.


I've gone through all possible ways for having the regular expression for the url validation, but I didn't get any.. what I need is the url can be like  google.com http://google.com https://google.com http://www.google.com https://www.google.com   but it should not allow if it is just google  finally the thing is the .extensions are mandatory  I've tried this /^[a-z0-9-]+(.[a-z0-9-]*)(.[a-z0-9-]*)$/  can anyone help me in this case..

I've been looking for a simple regex for URLs, does anybody have one handy that works well?  I didn't find one with the zend framework validation classes and have seen several implementations.


After reading , I am still not sure how to intuitively understand why eigenvectors of a covariance matrix represents direction of the LARGEST variance.   Need more explanation on:     Then $w^{T}Cw$ simplifies to $\sum\lambda_i w_i^{2}$ , in other words the variance is given by the weighted sum of the eigenvalues. It is almost immediate (why?) that to maximize this expression one should simply take $w=(1,0,0,…,0)$, i.e. the first eigenvector, yielding variance $\lambda_1$."   Here $C$ should be the original $C$ before decomposition? or both $C$ and $w$ have changed basis? If they changed basis, how do we know the original variance $w^{T}Cw$ is the same as the new variance $w^{T}Cw$?

I've read a lot about PCA, including various tutorials and questions (such as , , , and ).   The geometric problem that PCA is trying to optimize is clear to me: PCA tries to find the first principal component by minimizing the reconstruction (projection) error, which simultaneously maximizes the variance of the projected data.    When I first read that, I immediately thought of something like linear regression; maybe you can solve it using gradient descent if needed.  However, then my mind was blown when I read that the optimization problem is solved by using linear algebra and finding eigenvectors and eigenvalues. I simply do not understand how this use of linear algebra comes into play.  So my question is: How can PCA turn from a geometric optimization problem to a linear algebra problem? Can someone provide an intuitive explanation?  I am not looking for an answer like  that says "When you solve the mathematical problem of PCA, it ends up being equivalent to finding the eigenvalues and eigenvectors of the covariance matrix." Please explain why eigenvectors come out to be the principal components and why the eigenvalues come out to be variance of the data projected onto them  I am a software engineer and not a mathematician, by the way.  Note: the figure above was taken and modified from .


This is what my Galaxy Note 4 Android 4.4.4 shows in one of the answers to a question (it happens a lot), and it is probably not a device-specific issue I'd say.      All answers are shown properly but they often precede a lot of empty space. There were 7 full screens of empty space right after the above particular answer.

Noticed that sometimes when there are 10+ answers to a question - some answers look like they have \n\n...\n line breaks in the end, so the body of the answer has incorrect height.  It probably has something to do with ViewHolder or adapter not setting correct row height. Although as far as I know, it should do this according to text amount/length.


How do I get an android media player without going to the google play store ?  I will transfer the media player to the smartphone using bluetooth.  step 1: I download the android media player to my notebook.  step 2: I transfer the android media player to my smartphone.  step 3: I install the android media player on my smartphone.

I can't download apps from the Play Store on my Android device (maybe due to a network issue), so I'm wondering how could I download the APK file of an app on my PC from ?


I acquired an old factory bench grinder. It's a 380/220 3 phase 50 Hz unit. Can someone explain how to wire this to run on single phase 220 V (household power)?  I tried simply connecting the blue and brown leads to a 220 V outlet and spinning the unit by hand but that didn't work. I can hear the motor getting power, but it won't spin up.       Click images for full-size view.

I bought a small and old combi woodworking machine "Emco Start". The machine runs on 380V. The problem is that I only have 220 at home. I did some research and i found out that it is possible to get it run on 220 volts, by adding a capacitor. My problem is that I am not sure how to wire it to the motor, and I am not sure what is the needed value of the capacitor. The machine has a switch, so it runs with two speeds. The label on the motor shows :  Volts : 380/380 KW    : 0,37/0,51 U/min : 1430/2860  The wiring taken from the schematics is attached here.   U, V, U => from the motor to the switch (speed 1) WV, MV, VU => from the motor to the switch (speed 2)


Tesla Inc. (TSLA) recently announced a 5-for-1 stock split. The split takes effect on August 31 for each shareholder of record on August 21. So, what happens to people that buy shares of Tesla after the 21st? Do they not get the 5-for-1 split? I am interested in learning about this process but have not come across what happens to shareholders after the date of record for the split.

Stock split announcements usually mention a few dates — record date ("date of record"), split date ("distribution date", "pay date", or "payment date"), ex date ("ex-split date"). Examples:  :  Each Apple shareholder of record at the close of business on August 24, 2020 will receive three additional shares for every share held on the record date, and trading will begin on a split-adjusted basis on August 31, 2020.   :  Each stockholder of record on August 21, 2020 will receive a dividend of four additional shares of common stock for each then-held share, to be distributed after close of trading on August 28, 2020. Trading will begin on a stock split-adjusted basis on August 31, 2020.    In the case of the Tesla split, the record date is August 21, the split date is August 28 (Friday), and the ex date is August 31 (Monday). Apple's  provides definitions of these dates:  What is the effective date of the split? There are several key dates. The Record Date – August 24, 2020 - determines which shareholders are entitled to receive additional shares due to the split. The Split Date – August 28, 2020 - shareholders are due split shares after the close of business on this date. The Ex Date – August 31, 2020 - the date determined by Nasdaq when Apple common shares will trade at the new split-adjusted price.  However, further down in the FAQ, there is an explanation that seems to contradict the definition of the record date given above:  What happens if I buy or sell shares on or after the Record Date and before the Ex Date? [...] If you buy shares on or after the Record Date but before the Ex Date, you will purchase the shares at the pre-split price and will receive (or your brokerage account will be credited with) the shares purchased. Following the split, you will receive (or your brokerage account will be credited with) the additional shares resulting from the stock split.  Judging by the Apple FAQ, the way the record date works for stock splits is completely different from the way the record date works for cash dividends. With cash dividends, people who become shareholders of record after the record date are not entitled to the dividends. With stock splits, however, people who purchase shares after the record date (but before the ex date) are entitled to the stock split. Furthermore, for stock splits, the record date comes before the ex date, whereas for cash dividends, the record date comes after the ex date. It appears that I am not the only one confused about this. A quick internet search reveals years and years of confusion regarding the record date for stock splits. An extremely common point of confusion is the apparently incorrect assumption that the record date for stock splits works in the same way as the record date for cash dividends. A few questions:  Am I right that the record date for stock splits works differently from the record date of cash dividends? The only relevant dates for a stock split seem to be the split date (on which I will receive new shares after the market closes), and the ex date (on which I can sell the new shares on stock exchanges at a post-split price). It seems that the record date is completely irrelevant. What is the record date for? From my understanding, the price of the stock will be reduced at the instant the new shares are distributed (on the split date). Is this correct?


I open Chromium and the browser ask me if I want to set it as my default browser. I click on "set as default" and close the browser.  But when I open Chromium again I get the same question. Ubuntu 11.04 seems not to set Chromium correctly as my default browser.  How to fix that?

despite several attempts at making Google Chrome work as my default browser I simply cannot.  I've read countless threads on the internet, checked mimeapps.list and so on, tried about anything, from simple system configuration by going to settings and change as the default browser there, which, for some odd reason, won't allow me to set a default browser, to more advanced terminal scripting.  This is a clean install of Ubuntu 12.10 x64 bit updated to the latest version including kernels.


how can we prove by induction that a set of subtrees satisfies the Helly property of a tree T? i.e if a set of subtrees of T has the property that two of these subtrees have a common non-empty intersection, then the intersection of all the subtrees is also not empty I have drawn out some trees to prove that this is true but I'm not sure how to formally write out the proof

Can someone please verify my proof or offer suggestions for improvement? I am aware that there is a similar question elsewhere, but I want help with my proof in particular.     Let $T_1, \ldots, T_k$ be subtrees of a tree $T$ such that for all $1 \leq i < j \leq k$, the trees $T_i$ and $T_j$ have a vertex in common. Show that $T$ has a vertex which is in all of the $T_i$.   Suppose, for the sake of contradiction, that for every vertex $v \in V(T)$, there is a subtree $T'$ in the list $T_1, T_2, \ldots, T_k$ such that $v \notin V(T')$.  Pick $v_1 \in T_1$. There is a subtree $T^{(1)}$ such that $v_1 \notin T^{(1)}$. $T_1$ and $T^{(1)}$ have a vertex $y_1$ in common. Now, there exists a tree $T^{(2)}$ such that $y_1 \notin T^{(2)}$. But now, $T^{(2)}$ and $T^{(1)}$ have a vertex $y_2$ in common. Also, $T_1$ and $T^{(2)}$ have a vertex $y_3$ in common.  There exists a path $p_1$ in $T_1$ from $y_3$ to $y_1$. Also, there is a path $p_2$ in $T^{(1)}$ from $y_1$ to $y_2$ and a path $p_3$ in $T^{(2)}$ from $y_2$ to $y_3$. Note that the path formed by the union of $p_1$ and $p_2$ passes through $y_1$, while $p_3$ does not, since $y_1 \notin T^{(2)}$. Therefore, the union of $p_1, p_2$, and $p_3$ forms a cycle, contradicting the fact that $T$ is a tree. Therefore, it must be the case that there is a vertex $x$ in all of the $T_i$.


I am looking for an intuitive one word description for somebody that is being coached, as in enjoying the services of a coach.  I am thinking of something analogous to the oft used mentee as somebody being mentored, or enjoying the services of a mentor.

If I am Rita's coach, is Rita my *coachee? (yikes) Is that even a word? Would it be correct instead to say she is my ward? What about terms for people at the other end of a mentor, sponsor relationship?


So I made this method that reverses an array to use it in my code,and after running the code, using 3 as the size of the array and filling it with "1, 2, 3" the returned array i got is " [I@b7dd107"      public static int [] Reverse_Array(int x[]) {         int z=x.length-1;         int y[]=new int[z];         for(int i =0;i<y.length;i++) {             y[i]=x[z];             z--;}                  return y;     }     ```

In Java, arrays don't override toString(), so if you try to print one directly, you get the className + '@' + the hex of the  of the array, as defined by Object.toString():  int[] intArray = new int[] {1, 2, 3, 4, 5}; System.out.println(intArray);     // prints something like '[I@3343c8b3'   But usually, we'd actually want something more like [1, 2, 3, 4, 5]. What's the simplest way of doing that? Here are some example inputs and outputs:  // Array of primitives: int[] intArray = new int[] {1, 2, 3, 4, 5}; //output: [1, 2, 3, 4, 5]  // Array of object references: String[] strArray = new String[] {"John", "Mary", "Bob"}; //output: [John, Mary, Bob]


I'v already known that there are several assumpations when using linear regression model. But I cannot understand why some of them exists. They are:   independent errors normal distribution of errors homoscedasticity   Why cannot I just simply use least square method without these assumptions ?  I want to know how it affect the $R^2$, slope, and p-value if some assumptions are invalid. For example: "if the independent error assumption is false, the p-value is less then its true value."

What are the usual assumptions for linear regression?   Do they include:   a linear relationship between the independent and dependent variable independent errors normal distribution of errors homoscedasticity   Are there any others?


how to round off float value after two place decimal in c or c++  examples:    let input is 95.346789 so output is 95.35   let input 95.345 output is 95.35  let input 95.344 output is 95.34

What I would like is a method to convert a double to a string which rounds using the half-up method - i.e. if the decimal to be rounded is 5, it always rounds up to the next number. This is the standard method of rounding most people expect in most situations.  I also would like only significant digits to be displayed - i.e. there should not be any trailing zeroes.  I know one method of doing this is to use the String.format method:  String.format("%.5g%n", 0.912385);   returns:  0.91239   which is great, however it always displays numbers with 5 decimal places even if they are not significant:   String.format("%.5g%n", 0.912300);   returns:  0.91230   Another method is to use the DecimalFormatter:  DecimalFormat df = new DecimalFormat("#.#####"); df.format(0.912385);   returns:  0.91238   However as you can see this uses half-even rounding. That is it will round down if the previous digit is even. What I'd like is this:  0.912385 -> 0.91239 0.912300 -> 0.9123   What is the best way to achieve this in Java?


Let $V$ and $W$ be two non-trivial vector spaces over ${\displaystyle \mathbb {F}}$ and let $T: V\rightarrow W$ be a linear transformation. Prove that $T$ is onto iff $T^t$ is one-to-one. Now the only thing I know is that when T is onto if $\operatorname{range}(T) = W$ and it is $1:1$ when $\mathrm{Nullity} = 0$. I don't understand how to even start this question. If someone could give a hint at least, that would help me get started. (A similar question is already available on Stack Exchange but I could not understand the solution it had)

Let $V$ and $W$ be $F$-vector space, and $V^*$ and $W^*$ be the dual space of $V$ and $W$, respectly. Let $T:V \to W$ be a linear transformation. Define $T^*:W^* \to V^*$ by $T^*(f)=f\circ T$ for all $f\in W^*$. Show that $T$ is onto if and only if $T^*$ is one to one. My attempt: $T$ is onto $\implies$ $T^*$ is one to one: Since $T$ is onto, given $w\in W$, $\exists v\in V$, such that $T(v)=w$. Then, if $f,g\in W^*$ such that $T^*(f)=T^*(g)$, then $f\circ T\equiv g\circ T$,so $f\circ T(v)=g\circ T(v)$ $\forall v\in V$. For that given $w$ we earlier mentioned $f(w)=f(T(v))=g(T(v))=g(w)$, and since $w$ is arbitrary, we have $f\equiv g$. But the other direction of the proof I got stuck: $T^*$ is one to one $\implies$ $T$ is onto : Since $T$ is one to one, $\ker(T)=\{0\}$..., and I can't go further, thanks for help! Thanks martini, I have a typo, it should be proving $T^*$ is one to one $\implies$ $T$ is onto, does it use the same way?


Having a conversation this weekend, and this came up. Naively, I'd be inclined to simply label the brother of my brother-in-law a brother-in-law as well, since we've joined the families in a sense.   Specifically, my wife's sister's husband has two sisters. I call him my b.i.l., would they be s.i.l. by extension? Is this acceptable usage, or must I trod laboriously through the above description every time I describe the relationship?

For example:   I have a sister named Charlotte. Charlotte is married to Martin. Martin has a brother named William.   Martin is my brother-in-law, but what is William to me?


How do I make a C++ program call Python functions?  I know how to do the opposite, where Python functions call C++ functions by using a DLL, can it be used for this as well?

I would like to call python script files from my c++ program.   I am not sure that the people I will distribute to will have python installed.  Basically I'm looking for a .lib file that I can use that has an Apache like distribution license.


So i was uppdating Windows, and it restarted itself. When it booted itself up again, it had entered Grub rescue mode. This is what i get:  error: ’file /boot/grub/i386-pc/normal.mod’ not found Entering rescue mode... grub rescue>  It doesnt recognize any commands at all. I have tried to reinstall Windows using a USB thingy, although it just asks me to pull out the USB, but when i do that, it just boots into Ubuntu again.   All im asking for, is a way to either uninstall Ubuntu completely, since im not using it, or a way to install GRUB, so that i can open Windows again.  Im a total beginner to Linux/Ubuntu, so please, use simple language :)

error: file '/grub/i386-pc/normal.mod' not found. grub rescue>   What can I do? I just sit and stare at it.   I found my old netbook (Dell Inspiron 1010) which I have not used for about four years. I replaced Windows XP with Ubuntu 12.10. I used my bootable USB drive. I installed and rebooted. I got the message that normal.mod is not found.   What should I do? Type exit, reboot, or quit? Should I re-install?


I just found the sum of all Fibonacci numbers and I don't know if its right or not.  The Fibonacci sequence goes like this : $1,1,2,3,5,8,13,\dots$ and so on  So the Fibonacci series is this $1+1+2+3+5+8+13+\dots$  Let $1+1+2+3+5+8+\dots=x$  $$\begin{align} 1 + 1 + 2 + 3 + 5 + \dots &= x\\ 1 + 1 + 2 + 3 + \dots &= x\\ 1 + 2 + 3 + 5 + 8 + \dots &= 2x \text{ (shifting and adding)} \end{align}$$  We in fact get the same sequence. But the new sequence is one less than the original sequence. So the new sequence is $x-1$.  But $x-1=2x$ which implies that $x=-1$.  So $1+1+2+3+5+8+\dots=x$ which means... $1+1+2+3+5+8+13+21+\dots=-1$  Is this right or wrong? Can someone please tell? Thanks...

Today I believe I had found the sum of all the Fibonacci numbers are from $1$ to infinity, meaning I had found $F$ for the equation $F = 1+1+2+3+5+8+13+21+\cdots$ I believe the answer is $-3$, however, I don't know if I am correct or not. So I'm asking if someone can show how $F = -3$.


what is Boolean [] ba[] supposed to mean? Is it an array (with name ba) of boolean type of an array of an array?

I have recently been thinking about the difference between the two ways of defining an array:   int[] array int array[]   Is there a difference?


Let $(x_n)$ be a Cauchy sequence in the metric space $(X,d)$ and $a \in X$. Show that there exist $M>0$ such that $x_n \in B(a,M)$ for all $n \in \mathbb{N}$.  If $(x_n)$ is Cauchy we have that $\forall \varepsilon >0$ there exists $k \in \mathbb{N}$ such that $d(x_n,x_m) < \varepsilon$, when $n,m \geqslant k$. Let $\varepsilon =1$ I have $d(x_n,x_m)<1$ So $$d(a,x_n) \leqslant d(a,x_m) + d(x_n,x_m) = d(a,x_m)+1$$ I'm a bit stuck here. It seems that I want to get to $d(a,x_n)<M$, but I'm not sure how to achieve this?

Initially, I know that:   Convergent sequences are bounded. A sequence is convergent if and only if it is Cauchy.   Theorem. All Cauchy sequence are bounded.  My proof trying. Let $x_n$ be a Cauchy. Then, $x_n$ is converget by the $2$. So, by the $1$, $x_n$ is bounded. Hence, directlty, did I prove the theorem? Because $x_n$ is bounded.


public class CatalogActivity extends AppCompatActivity implements         LoaderManager.LoaderCallbacks {      private static final int PRODUCT_LOADER = 0;      ProductCursorAdapter mCursorAdapter;      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_catalog);          ListView productsListView = (ListView) findViewById(R.id.list);          View emptyView = findViewById(R.id.empty_view);         productsListView.setEmptyView(emptyView);         ProductCursorAdapter mCursorAdapter = new ProductCursorAdapter(this, null);         productsListView.setAdapter(mCursorAdapter);          FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);         fab.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View view) {                 Intent intent = new Intent(CatalogActivity.this, AddProductActivity.class);                 startActivity(intent);             }         });           productsListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {             @Override             public void onItemClick(AdapterView adapterView, View view, int position, long id) {                 Intent intent = new Intent(CatalogActivity.this, DetailEditActivity.class);                 Uri currentProductUri = ContentUris.withAppendedId(ProductContract.ProductEntry.CONTENT_URI, id);                 intent.setData(currentProductUri);                 startActivity(intent);             }         });        Log.e("working fine" , "product");         getSupportLoaderManager().initLoader(PRODUCT_LOADER, null, this);     }   And the onLoadFinished() method is :        public void onLoadFinished(Loader loader, Cursor data) {          mCursorAdapter.swapCursor(data);     }   I keep receiving the error as following :  java.lang.NullPointerException: Attempt to invoke virtual method 'android.database.Cursor com.example.android.gloryinventory.ProductCursorAdapter.swapCursor(android.database.Cursor)' on a null object reference  Is there's something wrong with my code?  Thanks in advance.

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


if no expanded-name, how to get file type(image/audio or video) by java?  I want to write a function like this:  String getFileType(String filePath){    // TODO:...    return type; }

How do you get a Media Type (MIME type) from a file using Java?  So far I've tried JMimeMagic & Mime-Util. The first gave me memory exceptions, the second doesn't close its streams properly. How would you probe the file to determine its actual type (not merely based on the extension)?


I encountered a question at the end of a unit about how to use “think about” and “think of”. It’s stated that we use “think about” when we consider an idea or concentrate on it, and we use “think of” when an idea comes into our mind. The question is a fill-in question:  “I don't really want to go out with Tom tonight. I'll have to … an excuse.”  I think we have to put “think about”, because we have to consider or concentrate on an excuse. But in the answer section, “think of” is stated as the answer. Which one is grammatically correct? Isn’t “think of” wrong? Why?

Could someone help me to understand when I should use think of and when think about in sentences?  What is the difference between using one or the other?


When a text is in the enumerate environment, all the text is indented under the numbers. How can I remove the indentation from the text in the middle of the enumerate environment?  This is what I am looking for:    \documentclass{article} \usepackage{lipsum} \begin{document} \begin{enumerate} \item first\\ \lipsum[1] \item second\\ \lipsum[2] \end{enumerate} \end{document}

I want to insert a paragraph or possibly even a box with a background color into a list that uses the whole \textwidth. Something like this:  1st item     a subitem 1    b subitem 2  2nd item    a subitee  \begin{use the full width}    [ Here the text should use the full text width ignoring the list indent] \end{use the full width}    b subitem 3rd item   The list is a normal enumerate.


This is a task meant to be solved using graph theory. My intuition says that it is not possible, however I don't know how to prove it apart from just drawing graphs with seven nodes in various configurations of connections between those nodes. I will appreciate any help or nudge in the right direction. Thank you.

There are 25 students, and every student gives a chocolate to 5 other students. Is it possible for every student to receive a chocolate from exactly the 5 students they've sent chocolate to?  My first though is to construct this as a graph, with each student as a vertex so there are 25 vertices. And each vertex has a minimum degree of 5 since every student is sending out 5 chocolate.   Am I on the right track? How should I proceed next?


I want to automatically archive email in Evernote.  Is there a way in Gmail web-interface to automatically send all outgoing emails to BCC address?

Is there a way to have a copy of any message sent from a Gmail account sent to another address?  I've got any messages coming to my address copied to another (see  for one solution, setting up filters is another), but I haven't yet found a way to have outbound messages automatically copied.  Is there a way?


I am not sure whether the below statement can be done placing & inside $() so that each time & is replaced by 1,2,3,4 and 1 is added to it.  echo 1 2 3 4 | tr ' ' '\n' | sed "s/.*/$(echo expr 1 + &)/"   The above statement doesn't work  i get the output :  expr 1 + expr 1 + expr 1 + expr 1 +

I am trying to perform a mathematical operation with sed, but it continues to treat my variables as strings. The input is of this kind:  $ echo 12 | sed 's/[0-9]*/&+3/' $ 12+3   I'd like to have 15 as output. I need to do the operation and replace its mathematical result in only one passage, because I am running the program as a Python daemon, and I want to avoid passages like redirecting stdout on files, open those files, perform operations, extract the result, do the replacement. To me, sed seems the best to perform all in one line.  I've tried to cast both input and output in various ways like  $ echo 12 | sed 's/[0-9]*/int(&+3)/' $ echo 12 | sed 's/[0-9]*/\int(&+3)/' $ echo 12 | sed 's/[0-9]*/\int(&+3)/'   but the result was always a printing of the second field.


I have a mobile timeline with cards, each card can be swiped to the right to display interaction options. We feel that it's not evident to the user that there's anything there, the 3 dots we've added are meaningless.    Is there some form of indication that means "swipable" that we could give the user, beyond giving them a guided tour of some sort.

Working on a mobile checkout page and would like to know if you'll think its intuitive enough that the user knows there are more products on the right side that could be reached by swiping using the 2 following ways  -showing half of the next item in the cart partially faded to white  -a horizontal scroll bar    are both of these really needed or is one of these enough for the user to get it. if so which one?


If you open up XCode (or probably another IDE) and type in __ you can see a lot of variables which starts with __. (in the auto complete box).  Why did the developers add the _s in there?

It's common in C++ to name member variables with some kind of prefix to denote the fact that they're member variables, rather than local variables or parameters. If you've come from an MFC background, you'll probably use m_foo. I've also seen myFoo occasionally.  C# (or possibly just .NET) seems to recommend using just an underscore, as in _foo. Is this allowed by the C++ standard?


I am experiencing a strange problem while running drush commands on newly installed server and newly installed drush(it's been installed with composer). Exact the same configuration works fine on my local machine (composer, drush-dev, memcached with 11212 port), but for some reason it doesn't execute any command on my production server. I've already read , but it did'nt help, I am sure problem is not coming from my memecached config, I can open it from browser without any error (Memcache Storage: server 127.0.0.1:11212 (default cluster) - Connected - message from status report).  So, I properly installed composer (globally), successfully installed a drush-dev version, env PATH has been added to .bashrc file, I can only run drush command which outputs .. But if I run any other command in my drupal root driectory it just hangs with  (for ex: drush status -vvvv -d).  Some addition info: 1. I digged into the drush files to find something and I found that drush calls _drush_bootstrap_drupal_login after _drush_bootstrap_drupal_full to login as uid=0, but somehow it can't login.. 2. I am using Memcache Storage module as cache backend, It shows Successfull connection in admin report page, but somehow it doesn't see pecl memcache extension I think.. If I remove $conf['lock_inc'] = 'sites/all/modules/memcache_storage/includes/lock.inc'; from settings.php file drush does WORK, but the same configuration is working on my local machine.. Very strange..  How can I solve this?

Running Ubuntu 12.04 with the 14.04 backports for Drush (meaning we are running Drush 5.10.0)  After importing the database (with drush sqlc < dump.sql), Drupal is no longer able to be bootstrapped by Drush.  drupal-site@uat-previewweb1:/var/www/drupal/uat-preview/current$ drush st -v -d Bootstrap to phase 0. [0.01 sec, 3.81 MB]                            [bootstrap] Drush bootstrap phase : _drush_bootstrap_drush() [0.01 sec, 4.04 MB] [bootstrap] Loading drushrc "/etc/drush/drushrc.php" into "system" scope. [0.01 sec, 4.04 MB]                                                                            [bootstrap] Cache HIT cid: 5.10.0-commandfiles-0-42f7d1cb79623ad6de6c23932c9a4e2b [0.02 sec, 4.07 MB]                                                                        [debug] Bootstrap to phase 0. [0.06 sec, 9.04 MB]                                                                                [bootstrap] Drush bootstrap phase : _drush_bootstrap_drupal_root() [0.08 sec, 9.04 MB]                                                                                [bootstrap] Initialized Drupal 7.31 root directory at /var/www/drupal/uat-preview/releases/20140911-4 [0.09 sec, 10.69 MB]                                          [notice] Drush bootstrap phase : _drush_bootstrap_drupal_site() [0.09 sec, 10.7 MB]                                                                                [bootstrap] Initialized Drupal site uat-preview at sites/default [0.09 sec, 10.7 MB]                                                                                [notice] Cache HIT cid: 5.10.0-commandfiles-2-c32acd775c18a90c5b41d0fc9accf5ab [0.09 sec, 10.71 MB]                                                                       [debug] Drush bootstrap phase : _drush_bootstrap_drupal_configuration() [0.1 sec, 10.75 MB]                                                                          [bootstrap] Drush bootstrap phase : _drush_bootstrap_drupal_database() [0.1 sec, 10.81 MB]                                                                               [bootstrap] Successfully connected to the Drupal database. [0.1 sec, 10.81 MB]                                                                                [bootstrap] Drush bootstrap phase : _drush_bootstrap_drupal_full() [0.12 sec, 11.92 MB]                                                                                [bootstrap]   The command hangs here and does not return.  Does anyone have any ideas on what could be causing this? Is it worth it to stray from debian packages and run Drush 6.4.0 here?


I have the following script named run.sh:  #This is run.sh  prerequisite(){  config_file=./../config/config.sh source $config_file      echo "VAR1 inside prerequisite: $VAR1"     echo "country currency inside prerequisite: $country_currency[@]" }  LIST_OF_COUNTRIES=`cat country_list.txt`  transform() {     local country="$@"     prerequisite     echo "VAR1 inside transform: $VAR1"     echo "country currency inside transform: $country_currency[@]" }  transform ${LIST_OF_COUNTRIES[@]} & transformpid=$!  wait $transformpid  echo "Complete"   The content of my config.sh file is:  VAR1="value1" declare -a country_currency=( "INR" "USD" "JPY" )   When I run my run.sh file,  I get the following output:  VAR1 inside prerequisite: value1 country currency inside prerequisite: INR USD JPY  VAR1 inside transform: value1 country currency inside transform:   As I see from the output, the value of all the variables that I am sourcing from my config .sh file is getting fetching into the prerequisite function.  Whereas the values in the array are not getting fetched into the transform function. This is just a small snippet of code. I am doing multiple calls to the prerequisite function to dynamically source the values in my actual code. What am I doing wrong over here? Isn't the scope of the variable and the array that I have declared, supposed to be the same?

Please explain to me why the very last echo statement is blank? I expect that XCODE is incremented in the while loop to a value of 1:  #!/bin/bash OUTPUT="name1 ip ip status" # normally output of another command with multi line output  if [ -z "$OUTPUT" ] then         echo "Status WARN: No messages from SMcli"         exit $STATE_WARNING else         echo "$OUTPUT"|while read NAME IP1 IP2 STATUS         do                 if [ "$STATUS" != "Optimal" ]                 then                         echo "CRIT: $NAME - $STATUS"                         echo $((++XCODE))                 else                         echo "OK: $NAME - $STATUS"                 fi         done fi  echo $XCODE   I've tried using the following statement instead of the ++XCODE method  XCODE=`expr $XCODE + 1`   and it too won't print outside of the while statement. I think I'm missing something about variable scope here, but the ol' man page isn't showing it to me.


I customise my "about me" field to match each site I use, so for example,  I have a list of games that I play and the types of games I'm interested in,  I have a list of movies and TV shows that I watch, and on sites where I provide edits I state I'm no expert on the subject matter but that I exist to provide edits.    If I were to want to make a chance to, for example, my Display Name, Email, Website, Location, etc and apply it to all websites, because of the way the "Save And Copy Profile To All Stack Exchange Accounts" works, I would have to edit each profile individually to preserve my "About Me" sections.  Would it be possible to have a button that only applies the settings in the top half of the profile page (Display Name, Email, Real Name, Website, Location, Birthday) but leaves "About Me" section alone?

Could there be a list of checkboxes to single out which information to update when copying profile info to linked accounts?  For example, if you had moved and only wanted to update your location information, you wouldn't want to destroy custom display names and custom profiles on various sites.  It could be hidden behind some "advanced copying" button, or the default is to tick every checkbox, so the basic functionality is still there.  I've just accepted that more detailed site-specific profiles are just too much work, but I do keep an extra blurb about code on SO (my most active SE site).  Today I decided to sync my other profiles (without that irrelevant blurb copied when they were created).  I forgot it copied display names, so I lost my Meta name for a month (I love that feature delay).  Regardless of display name, since you can change the other information manually without delay, if this was easier, wouldn't it encourage more detailed and site-relevant bios?    I am mostly focusing on the bio part of the profile page here (rather than the display names, even though I like that too), because I think site-specific bios can be very useful if you can use them easily.  I've not even considered it, except for SO and Meta, because it would be so much manual work too easily wiped out (as I've done now for Meta); surely others would start to use them if it was easier?  Instead of the above solution, could there be a "locked" checkbox when editing a profile (and hence seen when changing a bio to be site specific), so that particular bio isn't updated when copying profile information?


How do you transfer all setting & metadata (not data) from a sandbox to production? I have just joined a project which has been tested and approved by the client. My first job is to move everything (only dummy data in the system currently so this isn't important) from the sandbox into production now that it has been signed off. We have tried using a change set, which didnt feel right as there were so many options to select and it threw errors when we tried to import anyway... I have been trying to export everything into an unmanaged package, again when I try to import, it throws lots of errors saying things are missing. I'm struggleing to find an info/process for moving everything over in bulk. Can somone please explain the process for moving and validating everything in a sandbox environment that has been copied to production?

I used a Developer Sandbox that was created on developer.salesforce.com. I've been building on it for a while and recently purchased my own Salesforce instance. I was miffed when I realized the Developer Sandbox did not have a Change Set option in Setup. I assumed I would be able to connect the two and deploy one to the other or there would be a way to create my Production org off of the Developer org I've been building on. However, I have not found anything online.  Has anyone encountered this? Does anyone have any ideas on a solution?


I am using Ubuntu 20.04 on my raspberry pi 4. As I tried to upgrade, I noticed that the sources are only http. Are they the official right ones? Can someone please share the proper sources? Why doesn't it use https? Is it not official? It seems to be very unsafe to me. Here are the sources used on my pi currently: deb http://ports.ubuntu.com/ubuntu-ports focal main restricted                                                                                deb http://ports.ubuntu.com/ubuntu-ports focal-updates main restricted deb http://ports.ubuntu.com/ubuntu-ports focal universe deb http://ports.ubuntu.com/ubuntu-ports focal-updates universe deb http://ports.ubuntu.com/ubuntu-ports focal multiverse deb http://ports.ubuntu.com/ubuntu-ports focal-updates multiverse deb http://ports.ubuntu.com/ubuntu-ports focal-backports main restricted universe multiverse  deb http://ports.ubuntu.com/ubuntu-ports focal-security main restricted  As also as focal-security universe and focal-security multiverse and src. (Cant be posted, due to reputation, sorry. ) Thank you!

I always see instructions for adding the Universe and Multiverse repositories that look something like the following:  sudo add-apt-repository -y "deb http://archive.ubuntu.com/ubuntu $(lsb_release -sc) main universe restricted multiverse"   Recently I tried editing this to use HTTPS instead and was dismayed to find that archive.ubuntu.com doesn't appear to respond to HTTPS. Now I wonder how feasible it would be, or what damage could be done, if an attacker were to successfully perform a man-in-the-middle attack here?  Am I being too paranoid, considering the role these repositories perform on a system?


I am looking for a free tool for drawing diagrams (either for OS X or online). My goal is to keep for myself a clear trace of the organization of my project. Something like .  Any ideas?  Actually, I want to design a .

I'm seeking a Mac app for creating basic flowcharts and similar diagrams.   Google has been no help; I've followed dozens of links to apps that either don't exist anymore, I can't find any real reviews of, or that won't run on OS X 10.6.6.  What I'd really like:   A simple and clean interface Basic shapes Automated connectors that stay linked as you move shapes around Inexpensive, preferably under $30 but definitely under $50   What I'm not looking for:   Hundreds of shapes  Default styles that have shadows and textures and such that I have to keep removing Dozens of amazing features that allow you to automatically map databases and draw UML diagrams from code and such (I'm looking at you, Visio) that I have to constantly navigate around to make a few basic diagrams A mind-mapping app with all the features such a thing entails, one that happens to also let you make basic diagrams A full-fledged drawing app where, once again, I have to maneuver around a whole bunch of features and options to get to the basic functions I need.  (I have Illustrator, I love Illustrator, but it's crap for basic flowcharts and other simple diagrams.)   I wouldn't actually use it for flowcharts, but rather basic similar diagrams to show data flow between apps, information flow in a company or other places, that kind of thing.  I recently found out that the drawing portion of Google Docs actually does a pretty good job with the types of diagrams I need to create, but the UI is pretty poor and it obviously requires a constant net connection.


I’m looking for internationally applauded  textbooks on fundamental biology. Books that are a must for a pre-medicine student/high school advanced. Currently, I study Biology by Neil Campbell, Jane Reece(and team) and I really like it. What I’m looking for is 21st century pedagogy and a modern writing style(as opposed to a stiff, unfriendly writing style that reads like a fact presentation pamphlet); books so good you don’t need an amazing teacher(which I definitely do not have.) Thanks.  P.S.- If you have come across amazing books in branches of biology like say biochemistry or neuroscience or immunology, even those suggestions are welcome. P.P.S- My question is distinct from the “Books for beginners” question asked by user31782 because: 1.cost is no bar 2.I am not a beginner in biology, I’m studying pre medicine; and 3.All the resources suggested in the answers, I already know about them/have used them.

I want to study biology. I have zero previous knowledge of biology but I know Physics, Chemistry and Maths. From which book should I start? I have heard about Campbell Biology, but it is very costly in India(more than my 1 month's earning). So please suggest books that:       Are cheap OR  could be found on internet  Require no previous knowledge of biology   Contain no technical mistakes Adequately explain the topics which they deal with and also mention some history of the topics      Edit  I am not looking for online videos. I want books; my internet is slow and there are some other problems. You can also tell costly books--Perhaps I could find them in the library or could print it somehow. If Campbell Biology book is available online then please give me the download link.


I want to know how does Ubuntu install software. For instance I know that executables are moved in /usr/bin and .desktop files in /usr/share/applications but I want to know why and know more about it.

In Windows there’re perhaps only a couple of important folders (by important I mean important in my logical picture of the Windows file system) in the installation drive (in my case C:\). Namely Program Files and Windows. I simply stay away from Windows folder and the “add remove program files” is good enough to handle the program files folder of Windows. Of course there’s a folder named Users where the users (who are not admins) can access only their folders.  Thus there’s a clear picture at some level in my mind of the Windows file system. In Ubuntu, when I reach the location /, there’s a huge list of folders, most of which I have no clue as to what they contain. The /bin folder seems to be the equivalent of the Windows folder in windows. The /usr folder seems like it’s the equivalent of the Users folder in Windows. But even the /home folder looks like it can fit the bill.  Please understand that I do understand, that Ubuntu (Linux) has a different character than that of Windows, i.e., there need not be exact equivalent of Windows functions, in Ubuntu. All I am looking for is a bit more clearer picture of the Ubuntu file system.   This question is a part of a bigger question which I am splitting up to make it more answerable. The original question can be found here:


Alright so I have got a database that contains data of some different countries such as capital, continent, population. In my language, the continent Asia is translated to Azië. But when I import the data through a query it displays it like this: Azi�  <!DOCTYPE html>         <title>Opdracht 36</title>     <meta charset="utf-8" />

                    land_id	           land	           hoofdstad	           werelddeel	           inwoners
       <?php          $servername = "localhost";         $username = "root";         $password = "";         mysql_connect($servername, $username, $password);         mysql_select_db("Enigma");         $query = "SELECT * FROM landen ORDER BY werelddeel";         $result = mysql_query($query);         while ($row = mysql_fetch_array($result))          {       ?>
         <?php echo $row["land_id"]; ?>	         <?php echo $row["land"]; ?>	         <?php echo $row["hoofdstad"]; ?>	         <?php echo $row["werelddeel"]; ?>	         <?php echo $row["inwoners"]; ?>
       <?php         }       ?>

I'm setting up a new server and want to support UTF-8 fully in my web application. I have tried this in the past on existing servers and always seem to end up having to fall back to ISO-8859-1.  Where exactly do I need to set the encoding/charsets? I'm aware that I need to configure Apache, MySQL, and PHP to do this — is there some standard checklist I can follow, or perhaps troubleshoot where the mismatches occur?  This is for a new Linux server, running MySQL 5, PHP, 5 and Apache 2.


In the limited number of questions I have asked on Stack Exchange, I have had several comments and answers that are not answering my question, but are instead saying that I should be asking something else.  The most recent example is at , which basically asks how to increment the value of a GUID variable by 1. In the comments, user "atlaste" explains why this may be a bad idea, and that some people use dedicated hardware for similar things, but nothing relating to my question or its phrasing.  I understand this in general -- in my own life I find that when people come to me with a question, I often want to better understand where they are coming from to make sure my answer really fits their problem. I see this partly as a way to reduce the risk of miscommunication, and partly to reduce the risk that the person did not think the problem through.  But it is my predisposition to think that in a Stack Exchange site, we should assume that the questioner knows at least approximately what they want. Because even if the question was not the best for that one person, the answer should apply to the question so that future users will find this question and answer to be useful.  So my question is, to what level is it acceptable to dispute the premise of the question that is being asked?  This is related to , but I believe slightly different. Seeing this as the "XY Problem" assumes that you have that problem. Here I am asking, "To what extent is it okay to assume that the question is an instance of the XY Problem?"  Here is a (somewhat ludicrous) example of a problem, with background, and the question I could ask at the end of it.   I want to have a pretty house I decide that pretty is "feng shui", with all those crazy rules and oblique lines I want to rebuild my garage to have oblong walls I decide to do this be hand, and use a sledgehammer to rip the walls apart I injure my back by doing this with no training I ask the question: "What is the right way to use a sledgehammer so that it does not hurt your back?"   Now if you want to apply the "XY Problem" here, you could question many things. And the more details I give of the background problem, the more you could question the premise.   Why did I use manual sledgehammer instead of some "power" hammer Why did I try to use a sledgehammer without formal training -- go get some real training instead Why did I use a sledgehammer myself -- go pay a contractor instead Why did I use a sledgehammer at all, instead of a saw Why don't I just buy a new house instead Why do I like "feng shui" Why should houses be pretty   In my opinion, you cannot go all the way back up the stack; it is ridiculous to do so. So is it ever okay to debate the premise? How do you know how far is okay to go?

One thing I keep running into on this site is that some questions are merely asked so that a persons opinion can be validated.  I don't ever say I'm right and you're wrong when I reply to a question, but there are times I answer with a response that basically says, 'this question isn't really valid for x reason', or 'there is something more important to consider than what you're asking'.  In my mind I'm offering an answer to the fundamental validity of the question.  Most times, as I guess I should expect, my answer is down voted.  However, I do feel that it is important to step back sometimes and evaluate the validity of a question and the foundation it is asked on.  Is this accepted and acknowledged in the community, that some answers are 'No you can't', or 'that is not a valid question because of the premise it is asked on, because...'?  EDIT Example:  Like for instance, in parenting area if someone asks something obvious like 'How do I teach my 3 month old the alphabet'? My answer would be    you can't  you should not be trying to do that.   That was an obvious example, but there are other situations that are not as obvious, yet still 'you shouldn't do that or try that' may still apply or at least be a valid consideration


I know this question sounds ridiculous but it's important and I need to know the answer. If I knew that somebody in Ireland was in trouble and needed help (say for example: an ambulance) but there was no one else around them that could help them, how would I go about calling emergency services for them?   For example: I am on the phone to a friend in Ireland every day and I worry about how would I be able to help them if something came on suddenly (like they starting having a fit or something) and they weren't able to hang up our call and dial emergency services themselves.  I've done my research and already know that 999 and 112 are the main numbers for emergency services in Ireland, but would my call even go through to them? I'm in the US and don't have international calling, so my calls won't even go through to any other numbers outside of the US (though I can receive them).   Would I have to dial an area code before dialling 999 or 112? If you dial 999 or 112 in the United States, will you be connected to something else entirely? (Like a 411 type of deal?) or what if I just dialled 911 and explained the situation, would THEY get in contact with emergency services in Ireland?

I don't want to know the emergency number in case I'm IN a different country. What I want to know is, if I am, say, in France, and I know someone in Sweden needs emergent services, how can I call, from France, the emergency services in Sweden? Forgive me if that sounds confusing, but I'm surprised nobody has asked this question, even if it may be stupid. I'm wondering if I can call help for someone in a different country, if I know they need help and am the only one able to call, maybe by adding a country code. Would that work?


For example, Jarl Balgruuf the Greater. I have hit him several times and he still lives.

I always try to kill Jarl Balgruuf but he always comes back to beat me.  It's really annoying. It happens with most of the NPCs, not only those from Whiterun.


In the Star Trek universe we do see usage of "attack wings" (as shown in many of DS9's episodes) and by Starfleet.   However are these attack wings actually housed on larger carriers or are they independent ships capable of warp?  Furthermore does anyone know of any cannon usage of carriers as a regular part of the military (I wouldn't personally count the usage of a shuttle or two as having attack ships) by the Federation or other factions such as the Klingons or Romulans (in the example of the Romulans the scimitar wouldn't count as it was only built once and not a regular vessel type -- as far as I know)  Also I know some games such as STO use carriers but I would prefer evidence from books or screen.

All of the ships of every species seem to be medium to large vessels with multiple crew members. Why aren't there single fighter craft and carrier ships to transport them in mass?  I've just noticed the difference between Battlestar Galactica and Star Trek, where the former has primarily aircraft carriers, and the latter has battleships.   Wouldn't a huge fleet of small fighters be extremely maneuverable and possibly stealthy?  Update:  For clarity, my question is not about the Federation and their choice of ships, but the universe at large. I would think there would be some diversity in space warfare strategy, such as huge armadas of fighters with base stations / carriers.


Can someone please help me eliminate a problem within my house? There is a device in my house which continues to use all of my router's bandwidth.  How can I find which device it is which is using all of my bandwidth?  I have the Virgin Media Super Hub 3 Router.

I need to know which computer is consuming my bandwidth. Is there a tool to do this?


Recent commitments means one of our group cannot attend our once monthly DnD game for a few weeks. We are in the middle of a campaign, a close knit group and we are usually always present at every meeting (there's only 4 of us). In the player's absence, we have done a few non-DnD evenings but we're all itching to get back into it, so it's been decided we'll do a little mini quest to scratch the DnD itch whilst one of our group is away. The players do not want to re-roll new chars. They want to play as their existing PCs.  I am unsure how best to proceed.    I could carry on from where we left off in the story and just somehow explain the absence of the PC for a while. This will take some story manipulating and will definitely feel contrived in some respects. Or... I could wind the clock back to an earlier time to do some quest that is assumed to have happened in the past but we just never actually looked at it before. Again, a little contrived but possible.   I would love to hear some of your experiences of handling this problem and any other ideas you may have for side quests that don't derail the main story but also don't require a whole lot of story wrangling.

If you know ahead of time that you're going to be missing a player, do you reschedule? Or just play them as an NPC or as a group puppet?


Is the same domain but i change url structure and website platform and is important to save all traffic from old links.

I have done major updates to my website, and renamed all my URLs.  How can I tell Google that I have renamed these URLs and let Google refresh its index?  My website URL: http://www.pndmasr.com/  My sitemap: http://www.pndmasr.com/sitemap.xml  I have uploaded my sitemap via Google Webmaster Tools many times.  However, every time I search Google for "pndmasr", I still get results with old pages. I have waited more than 3 days but the problem remains. Any suggestions?  Is there a problem with my sitemap?


everybody.  I'm suppose to prove this without induction: Prove Without Induction: $\sum\limits_{k=2}^{n} \frac{1}{k(k-1)} = 1 - \frac{1}{n}$  I'm not sure how to do it. I tried a bit of algebraic manipulation, but I'm not sure how to do it.  It's suppose to be basic.  I did get a hint of factorizing $\frac{1}{k(k-1)}$ but that didn't get me anywhere.  A hint or any directions would be much appreciated!

I oversaw a high-school mathematics test the other day, and one of the problems was the following     Show, using induction or other means, that $$\sum_{i = 1}^n\frac1{i(i+1)} = 1-\frac1{n+1}$$   The induction proof is very standard, where the induction step relies on the fact that $\frac{1}{n+1} + \frac{1}{n(n+1)} = \frac{1}{n}$, and I'm sure it's been answered on this site before. However, I got intrigued by the "or other means" part of the question.  I don't know whether the teacher who wrote the test even considered any alternative solutions (he may just have written it so that if anyone has a crazy idea that works out, then they should get a full score for it), but I tried to find one. For instance, we may do the following telescope-ish argument: $$ \frac{1}{1(1+1)} + \frac{1}{2(2+1)} + \cdots + \frac{1}{(n-1)n} + \frac{1}{n(n+1)} + \frac{1}{n+1}\\ = \frac{1}{1(1+1)} + \frac{1}{2(2+1)} + \cdots + \frac{1}{(n-1)n} + \frac1n\\ \vdots\\ = \frac{1}{1(1+1)} + \frac12\\ = 1 $$ However, I feel that this is just an induction proof in disguise (hidden in the vertical dots). If one uses the mechanics of the induction proof to check whether the formula is true for a specific $n$, then one certainly does the exact same calculations as I have done here.  Is there a proof of this fact that clearly does not use induction (or at least hides it better)? The more elementary the better, and the ultimate goal would be to do it within the syllabus of the students taking the test (or at least not far from it). For reference, they should be familiar with the summation formula of arithmetic and geometric series and their derivations (so techniques resembling those would be well within specifications).  If there is a solution using calculus, then the students should be able to integrate elementary trigonometric functions, as well as exponential functions, logarithms and rational functions. They are familiar with integration by parts, substitution and partial fractions.  I welcome more advanced solutions as well, of course.


I am working through "General Relativity" by Wald, and am currently going through the brief section on Special Relativity. The spacetime metric is defined as $\eta_{ab} = \sum\limits_{\mu, \nu=0}^3 \eta_{\mu,\nu} (dx^\mu)_a(dx^\nu)_b$ where $\eta_{\mu, \nu} = \mathrm{diag}(-1,1,1,1)$. My question is, what is the physical motivation for this? The last three terms in the summation I understand - they give the physical distance between two events. But what about the negative sign infront of the "time term"?

In Special Relativity, the spacetime interval between two events is $s^2 = -(c{\Delta}t)^2+({\Delta}x)^2+({\Delta}y)^2+({\Delta}z)^2$ giving the Minkowski metric $\eta_{\mu\nu}=\text{diag}(-1, 1, 1, 1)$. What is the justification for making time have a negative coefficient, and how closely is that related to the 2nd law of thermodynamics? Sure, by letting $\eta = \text{diag}(1, 1, 1, 1)$, we get a pretty boring spacetime, and the boosts in the Poincaré group become trig instead of hyperbolic functions, but what's the physical reasoning behind this?


Prove    $$\sin\frac\pi7 \cdot \sin\frac{2 \pi}{7}\cdot\sin\frac{3 \pi}{7} = \frac{\sqrt7}{8}$$   I tried using the product to sum identities but those got me nowhere. Any help would be great.

Evaluation of $$\sin \frac{\pi}{7}\cdot \sin \frac{2\pi}{7}\cdot \sin \frac{3\pi}{7} = $$   $\bf{My\; Try::}$ I have solved Using Direct formula::  $$\sin \frac{\pi}{n}\cdot \sin \frac{2\pi}{n}\cdot......\sin \frac{(n-1)\pi}{n} = \frac{n}{2^{n-1}}$$  Now Put $n=7\;,$ We get   $$\sin \frac{\pi}{7}\cdot \sin \frac{2\pi}{7}\cdot \sin \frac{3\pi}{7}\cdot \sin \frac{4\pi}{7}\cdot \sin \frac{5\pi}{7}\cdot \sin \frac{6\pi}{7}=\frac{7}{2^{7-1}}$$  So $$\sin \frac{\pi}{7}\cdot \sin \frac{2\pi}{7}\cdot \sin \frac{3\pi}{7} =\frac{\sqrt{7}}{8}$$  Now my question is how can we solve it without using Direct Formula, Help me  Thanks


I'm working on some quiz script, found one from internet, everything works like a charm, but i need to modify for security reasons. Actually i use $_GET , but i'm afraid about sql injections.  I'll let here all my script, and if someone can help me with suggestions, will be great. I tried so many things to make script non-vulnerable, but even .htaccess didn't helped me!  1.php quiz page with form  <?php     //Set question number     $number = (int) $_GET['n'];      //Get total number of questions     $query = "select * from questions";     $results = $mysqli->query($query) or die($mysqli->error.__LINE__);     $total=$results->num_rows;      // Get Question     $query = "select * from `questions` where question_number = $number";      //Get result     $result = $mysqli->query($query) or die($mysqli->error.__LINE__);     $question = $result->fetch_assoc();       // Get Choices     $query = "select * from `choices` where question_number = $number";      //Get results     $choices = $mysqli->query($query) or die($mysqli->error.__LINE__);   ?>  <?php echo $question['question'] ?>  <form method="post" action="../p/process.php" class="table-responsive"> <?php while($row=$choices->fetch_assoc()): ?>  <button type="submit" class="btn btn-info btn-block" name="choice" value="<?php echo $row['id'] ?>"><?php echo $row['choice']; ?></button>  <?php endwhile; ?>                                                                                <input type="hidden" name="number" value="<?php echo $number; ?>" /> </form>   process.php page   //Check to see if score is set_error_handler     if (!isset($_SESSION['score'])){        $_SESSION['score'] = 0;     }  //Check if form was submitted if($_POST){     $number = $_POST['number'];     $selected_choice = $_POST['choice'];     $next=$number+1;     $total=10;      //Get total number of questions     $query="SELECT * FROM `questions` LIMIT 10";     $results = $mysqli->query($query) or die($mysqli->error.__LINE__);     $total=$results->num_rows;      //Get correct choice     $q = "select * from `choices` where question_number = $number and is_correct=1";     $result = $mysqli->query($q) or die($mysqli->error.__LINE__);     $row = $result->fetch_assoc();     $correct_choice=$row['id'];        //compare answer with result     if($correct_choice == $selected_choice){         $_SESSION['score']++;     }      if($number == $total){         header("Location: ../final.php");         exit();     } else {             header("Location: ../f/1.php?n=".$next."&score=".$_SESSION['score']);     } }   As like i said, everyhing works fine, i'm ussing that script for 2 months already, but i'm afraid. Current URL looks like: f/1.php?n=1&score=1 Will be nice if someone can help me. Thank you

If user input is inserted without modification into an SQL query, then the application becomes vulnerable to , like in the following example:  $unsafe_variable = $_POST['user_input'];   mysql_query("INSERT INTO `table` (`column`) VALUES ('$unsafe_variable')");   That's because the user can input something like value'); DROP TABLE table;--, and the query becomes:  INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')   What can be done to prevent this from happening?


import java.io.*; class threads extends Thread{     int counter=0;     static volatile boolean counting=true;     public void run(){         if(counting) {             counter++;         }     } } public class cores {     static PrintWriter pw= new PrintWriter(System.out, true);     @SuppressWarnings({ "static-access", "deprecation" })     public static void main(String args[]) throws InterruptedException {         int mastercounter=0;         Thread mainthread=Thread.currentThread();         int cores= Runtime.getRuntime().availableProcessors();               threads[] array=new threads[cores];         for (int x=0;x<cores;x++) {             threads t=array[x];             t.start();         }         mainthread.sleep(5000);         threads.counting=false;         for (int x=0;x<cores;x++) {             threads t=array[x];             t.stop();             mastercounter+=t.counter;         }         pw.println(mastercounter);     }   The code above is my attempt at a simple benchmark program that tries to take advantage of all cores available on the CPU of a computer by simply using all the threads possible to count in 5 seconds. The code gives a NullPointerException on the line t.start() which I assume is because of the way I tried to work around not being able to name variables dynamically. Any advice, fixes or tips are much appreciated.

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


Consider the ring $R[x,x^{-1}]$ where $R$ is a commutative ring. I want a description of the ring after completing at the ideal $(1+x)$. So my guess is that it is isomorphic to $R[[y]]$, where the isomorphism is given by $y \to 1+x$. The reason I guessed this was because $x$ is already invertible after completing at the ideal $(1+x)$. So intuitively I think it should be same as $R[x]$ completed at the ideal $(1+x)$ and therefore the guess. Any help with proving this or any references are appreciated. Thanks in advance.

Let $A$ be a commutative ring and $\mathfrak{p}$ be a prime ideal of $A$. Under which assumptions for $A$ and $\mathfrak{p}$ does localization by $\mathfrak{p}$ and completion with respect to $\mathfrak{p}$ commute? To be more precise,      when is $\widehat{A}_\widehat{\mathfrak{p}}$ (completion w.r.t. $\mathfrak{p}$) isomorphic to $\widehat{A_\mathfrak{p}}$ (completion w.r.t. $\mathfrak{p} A_\mathfrak{p}$)?   For example, is it true under the assumptions $A$ noetherian and $\mathfrak{p}$ a maximal ideal?  It seems to me that one important ingredient for a possible proof (under the right assumptions) is that localisation and building factor rings commutes. So a side question: Is it always true that $A_\mathfrak{p}/(\mathfrak{p}A_\mathfrak{p})^k \cong (A/\mathfrak{p}^k)_{\overline{\mathfrak{p}}}$?  Thanks


When I use external display, I always use screen mirroring and set main display brightness to zero.  Macbook remembers screen mirroring config, but I must turn down the brightness manually every time the monitor is connected.  Is there a way to turn off main monitor automatically when external monitor is connected?  There are similar questions, but the first answer is about clamshell mode, and the second question's answers doesn't match my need. Because I want to brightness down automatically.

I went through a , but the answer was informing how to hide the monitor, but not how to disable it. I do not want any new windows to creep into the laptop display when the external display is connected. I could not find any in the Display Settings (under System Preferences). I don't want to close the lid because I think it impacts the air flow of the MacBook Pro. I don't want to close the lid because the sound quality is reduced.


On my company's SharePoint site (using SharePoint Online), in the permissions section there is a line stating Anonymous Users with a permission level of Entire Web site.   Can someone explain to me:   What this is, Why is it there, and How do I get rid of it?   This is in the top level site, I have 8 subsites representing the company departments, 7 of which do not show this Anonymous Users permission, 1 does which I would like to remove.  The site should only be viewable by company employees (using 356 Business Essentials subscription).  Employees should still be allowed to share documents from libraries to people outside the company.  I've have tried going through  where it is advised to disable guest links at the site collection, but I cannot see this option.

I've never seen this before. Our global and site level settings are 'don't allow sharing outside your organization' but today I noticed in the Site Permissions page an entry for Anonymous Users. It is not clickable and each time I check the box, it checks all other boxes. Does it impact our global settings? Or, how do I remove this permission?


I need to prove that if $S_1$ and $S_2$ are subsets of a set $X$, and if $f: X \to Y$ is an injection, prove that $f(S_1 \cap S_2) = f(S_1) \cap f(S_2)$.   I know I need to show inclusion in both directions but not sure how to begin.

Let $A$ and $B$ be sets, where $f : A \rightarrow B$ is a function. Show that the following properties are valid equivalent*:  $f$ is injective. For all $X, Y \subset A$ is valid: $f(X \cap Y)=f(X)\cap f(Y)$ For all $X \subset Y \subset A$ is valid: $f(X \setminus Y)=f(X) \setminus f(Y)$.   I do know what injective is, but I thought number (2.) and (3.) were valid for any kind of function. Just to see if I understood this right: $f(X\cap Y)$ means, first, make the intersection from $X$ and $Y$ and then map it to $B$ via $f$. $f(X)\cap f(Y)$ actually means, map all $f(X)$ and $f(Y)$ and intersect both. Aren't those both properties valid for all functions? I can't think of a counter example. Thanks in advance guys! *edited by SN.


While I can post external texts into question and answer bodies, it preserves the old font style, spacing and size (although the markdown display won’t be affected by that.)   App Version: 1.6.6.2 Device: iPhone 6 OS Version: Version 11.0.3 (Build 15A432)

I’m able to copy-paste from any application to any application. I’m able to copy from a comment or from a question or from an answer. I’m able to paste to a question or answer. However, if I attempt to paste into a comment, nothing happens. I am able to subsequently paste into another application, confirming that the text is actually on the clipboard.   However, copying SE links will paste them successfully, but all other text - including other links - still fails. This leads me to believe that it’s a SE issue and not an Apple one.   This has been an issue since 11.0 beta and persists through iOS 13 release.


I've unlocked the Panna City Medicines way back in December 2013. I have added 18 residential levels with two vacant slots each to increase my chance of finding a Bitizen with Panna City Medicines dream job. It's been 5 weeks and I've never seen any... Do they exist or just uncommon?

I've just gotten the reward for 35 decorations but it just occurred to me I've yet to see any bitizen with Panna City Medicines dream job. Or do they only trigger when you unlock the shop?


I have been approved for a second working holiday visa in Canada on my Dutch passport, after having used my New Zealand passport the last time for the working holiday visa. This time I want to fly from NZ to the USA and arrive into Vancouver on land.  Apparently, I can't get a visa waiver for the USA because Canada is included in the 90 days limit. I already have a multiple entry USA tourist visa on my NZ passport, though. Could I enter the USA on my NZ passport, and then enter Canada on my Dutch one? Any suggestions on how to navigate having two passports in this situation?

I'm on a New Zealand passport.  From most US Embassy webpages:     The Visa Waiver Program (VWP) enables nationals of certain countries,   including Australia, New Zealand, and the U.K., to travel to the   United States for tourism or business for stays of 90 days or less   without obtaining a visa, if certain requirements are met. Under the   VWP, time spent in Canada, Mexico, and adjacent islands counts towards   the maximum of 90 days stay allowed under the program.   I'll be there on a 1-year working holiday visa starting when I arrive in Vancouver. I'm spending 3 days in Hawaii en route to Vancouver. This seems to imply that 90 days after landing in Hawaii, my time will be up and I won't be able to get back into the US, as my living in Canada will not reset the clock. What if after this time I want to say, pop across the border to Seattle? How can I restart the 90 days, without having to resort to say, flying to Japan and back just to reset it?


I've downloaded the .deb file of the Brackets editor and tried to install it. It takes me to the Ubuntu Software Centre to install the file, then after the installation completes it shows the Install button, instead of showing the Launch and Remove buttons.   This happens every time I try to install a .deb file.  I'm running the latest Ubuntu 18.04.1 LTS update.

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


Question. Let $ X_1,\cdots,X_n $ be i.i.d. random variables with exponential distributions, $ X_i\sim Exp(\lambda) $. Find $E\left[  \max(X_1,\cdots,X_n) \right]$. My approach. Let's find a recursive relation in terms of $ n $. Define \begin{align*} &Y_1 = X_1,\\  &Y_2 = \max(X_1,X_2),\\ &\vdots\\ &Y_n = \max(X_1,\cdots,X_n).  \end{align*} We have the relation \begin{align*}   &Y_n = \begin{cases}   X_n\ &{\rm if}\ X_n>Y_{n-1},\\   Y_{n-1}\ &{\rm otherwise},   \end{cases}\implies Y_n = Y_{n-1} + (X_n-Y_{n-1})1_{\{X_n>Y_{n-1}\}}\\   &\implies E[Y_n] = E[Y_{n-1}] + E[(X_n-Y_{n-1})1_{\{X_n>Y_{n-1}\}}].  \end{align*} Now, using the independence of $ X_n $ and $ Y_{n-1} $, we have \begin{align*} E[(X_n-Y_{n-1})1_{\{X_n>Y_{n-1}\}}]& = \int_{0}^{\infty}\int_{0}^{\infty}(x-y)1_{\{x>y\}}f_{X_{n}}(x)f_{Y_{n-1}}(y)\ dx dy\\ & = \int_{0}^{\infty}\int_{y}^{\infty}(x-y)f_{X_{n}}(x) dx\ f_{Y_{n-1}}(y) dy\\ & = \int_{0}^{\infty}\dfrac{\exp(-\lambda y)}{\lambda} f_{Y_{n-1}}(y) dy  \end{align*} So, \begin{align*}   E[Y_n] = E[Y_{n-1}] + \int_{0}^{\infty}\frac{\exp(-\lambda y)}{\lambda} f_{Y_{n-1}}(y) dy.  \end{align*} But I do not know what to do with the inetgral.

A program is divided into 3 blocks that are being compiled on 3 parallel computers. Each block takes an Exponential amount of time, 5 minutes on the average, independently of other blocks. The program is completed when all the blocks are compiled. Compute the expected time it takes the program to be compiled. I know X follows an exponential distribution, so E(X) = 1/λ. But how do I define "λ" based on the parameters? The answer should compute to 55/6.


I want to prove that $$ w^2 \equiv 2 \quad (\bmod{5})$$ has no solutions in integers.  What I tried: $$ w^2 \equiv 2 \quad (\bmod{5})$$ $$ \Rightarrow w^2 =  2 + 5k,  \quad k \in \mathbb{Z} $$  Now, I don't know what to do, so I considered $x^2 = 2+ 5y$ over $\mathbb{R}$.  We can solve this to see if the solutions are integers.   If it has no solutions in integers, can I then say that this implies that $ w^2 \equiv 2 \; (\bmod{5})$ has no solutions? Is there a different approach to this problem?

There is not any perfect square $k$ such that $k  \equiv 3\ (\textrm{mod}\ 5)$? Why? How can I prove it?


I’m looking for a word/phrase/etc. to refer to that action/activity of constantly pointing out certain mistake/(so-called) flaw to the person having that flaw/doing the mentioned mistake. For example, I’m fat and I feel perfectly fine with being fat. But somehow my friend constantly tell me “Look at you, so fat” or “How about dieting?” or “You eat a lot, no wonder you’re fat.” Or I can’t use computer and I don’t mind not being able to operate it but my co-worker constantly tells me “You can’t use a computer” or “How sad, you don’t know how to use a computer.” and it happens every time we meet. Like they constantly slap the fact that I’m fat/I can’t use a computer to my face. However, I don’t think “to slap sth. to someone’s face” is the one I’m looking for. Edit: I think I’ve found it: “to rub something in someone’s face.” But please correct me if you think it’s not the one.

I usually tend to see the behavior in which someone takes an action, and people criticize, and even suggest what they should have done, yet when they take that same suggestion people still criticize.  For instance: I'm slim; when I eat with my family, everyone exclaims at the amount of food I'm eating. When I eat normally, they ask "Don't you know, you should eat more so you can grow better?" When I don't eat, the same shouting takes place. So in other words, is there a word I could use to describe them or their behavior in this regard?