In my Commission class i am trying to overwrite the pay method from the parent class (Hourly) to compute the pay for hours worked, how would i do this? My code for Commission and Hourly class which is the parent, is below, the overwriting takes place where i put the ????   public class Commission extends Hourly {   double total_sales;   double commission_rate;    public Commission(String name, String address, String phone,                     String soc_sec_number, double rate,double commission_rate)   {     super(  name,   address,   phone,                       soc_sec_number,   rate);     // set commission rate      commission_rate = 0.02;   }    public void addSales (double sales)   {     sales += total_sales;      /*????   */super.pay   }  }   and the Hourly class  // ******************************************************************** // Hourly.java       Java Foundations // // Represents an employee that gets paid by the hour // ********************************************************************  public class Hourly extends Employee {   private int hours_worked;    // -------------------------------------------------------------------------   // Constructor: Sets up this hourly employee using the specified information   // -------------------------------------------------------------------------   public Hourly(String name, String address, String phone,                 String soc_sec_number, double rate)   {     super(name, address, phone, soc_sec_number, rate);     hours_worked = 0;   }    // -----------------------------------------------------   // Adds the specified number of hours to this employee's   // accumulated hours   // -----------------------------------------------------   public void addHours(int more_hours)   {     hours_worked += more_hours;   }    // -----------------------------------------------------   // Computes and returns the pay for this hourly employee   // -----------------------------------------------------   public double pay()   {     double payment = pay_rate * hours_worked;      hours_worked = 0;     return payment;   }    // ----------------------------------------------------------   // Returns information about this hourly employee as a string   // ----------------------------------------------------------   public String toString()   {     return super.toString() + "\nCurrent hours: " + hours_worked;   } }

I have two Java classes: B, which extends another class A, as follows :  class A {     public void myMethod() { /* ... */ } }  class B extends A {     public void myMethod() { /* Another code */ } }   I would like to call the A.myMethod() from B.myMethod(). I am coming from the , and I don't know how to do this basic thing in Java.


I'm trying to remove my enemy sprite whenever they collide to a rectangle,I'm also using Pools.  while(enemyIterator.hasNext()){             Sprite sprite=enemyIterator.next();  //this is the line 65             if(enemyRect.overlaps(treeObj.treeRect))                 removeEnemy(sprite);         }   then on remove enemy method:  public void removeEnemy(Sprite sprite){         enemies.remove(sprite);         Pools.free(sprite);     }   I get this error:  Exception in thread "LWJGL Application"java.util.ConcurrentModificationException         at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901)         at java.util.ArrayList$Itr.next(ArrayList.java:851)         at com.dreamroad.savethetree.EnemyClass.update(EnemyClass.java:65)         at com.dreamroad.savethetree.MyGdxGame.render(MyGdxGame.java:51)         at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:215)         at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:120)   I followed the instruction from the question he linked and I still get the error, for now I'm only trying to remove the rectangles.  for(Iterator<Rectangle> rectIterator=rectangles.iterator();rectIterator.hasNext();){             Rectangle nextRect=rectIterator.next();             if(nextRect.overlaps(treeObj.treeRect))                 rectIterator.remove();         }

We all know you can't do the following because of ConcurrentModificationException:  for (Object i : l) {     if (condition(i)) {         l.remove(i);     } }   But this apparently works sometimes, but not always. Here's some specific code:  public static void main(String[] args) {     Collection<Integer> l = new ArrayList<>();      for (int i = 0; i < 10; ++i) {         l.add(4);         l.add(5);         l.add(6);     }      for (int i : l) {         if (i == 5) {             l.remove(i);         }     }      System.out.println(l); }   This, of course, results in:  Exception in thread "main" java.util.ConcurrentModificationException   Even though multiple threads aren't doing it. Anyway.  What's the best solution to this problem? How can I remove an item from the collection in a loop without throwing this exception?  I'm also using an arbitrary Collection here, not necessarily an ArrayList, so you can't rely on get.


I had a look at the most popular tags and I noticed that the last 80 or so pages of tags had never been used I was just wondering why they have so many unused tags

I was looking (randomly) through SO tags when I jumped to the  which have some tags like  which has Zero questions (among others).  Not sure if this a bug or I'm missing something here


As the title states, is it possible to have an alias only load when I access the machine through ssh, or better yet, only from a specific computer through ssh?

Whenever I login to my Linux server I'd like to have several commands run automatically (set some variables, change location, etc.)  This needs to be done on user login, not on system start.  How can I set it to do this?


This is my first post to stackoverflow, so please let me know if I don't follow the correct etiquette.  I am also new to Python and would like to incorporate it into a project.  I currently have a Emotiv EEG headset and would like to run a homebuilt 3-D Printer from brain signals.  To do so, the EEG headset is read by EmoKey 2.0.0.20 (see attached photo), EmoKey will then send keystrokes to the Python Shell, Python interprets this and sends commands to my Arduino run printer through a COM PORT.  This may seem to be an indirect way of doing things, but it works except for one hitch.  Lets pretend I think left, this is sent to EmoKey which types 'L' and the keystroke Enter into the Python Shell.  In theory this would then move the printer head left.  However, when EmoKey sends Enter it only creates a new line in the Shell, it doesn't actually execute.  I then have to press enter by hand, which defeats the whole point.    .getch() hasn't worked because I don't think there is an actual key stroke for it to read. The link below also seems like it would be useful, but It hasn't worked thus far.     My question is: How can I get Python to execute what is written in the shell when only something like L or R is written?  I don't think I can have it wait for a keystroke, Python would have to wait and automatically execute when it sees a specific command.   I understand that this may seem like a duplicate of the link below.  However, .getch hasn't worked with EmoKey so far (maybe it's just a mistake on my part).  Also, I wan't to find a way for my Python script to read what is put into the shell.  Although I've started this project with just the "L" and "R" commands for simplicity and prototyping, I will move into using G-code so I can communicate with other printers or CNC equipment.  That is another reason why .getch won't work in my case since it only grabs a single character (A single G-code command will be a few characters long).   I'm using Windows 10 and Python 2.7.11.   import serial  ser = 0  def init_serial():     COMNUM = 3          #Enter Your COM Port Number Here.     global ser          #Must be declared in Each Function     ser = serial.Serial()     ser.baudrate = 9600     ser.port = COMNUM - 1   #COM Port Name Start from 0      #ser.port = '/dev/ttyUSB0'       #Specify the TimeOut in seconds, so that SerialPort     #Doesn't hangs     ser.timeout = 10     ser.open()          #Opens SerialPort      # print port open or closed     if ser.isOpen():         print 'Open:'  + ser.portstr  init_serial()  while 1:      temp = raw_input('Send command + Enter:\r\n')     ser.write(temp)         #Writes to the SerialPort      #bytes = ser.readline()  #Read from Serial Port     #print 'Response: ' + bytes      #Print What is Read from Port

Is there a way of reading one single character from the user input? For instance, they press one key at the terminal and it is returned (sort of like getch()). I know there's a function in Windows for it, but I'd like something that is cross-platform.


First I'm german, so sorry for any mistakes. I've been on so many websites but not a single one could help me. I'm writing my Bachelor thesis and all I still need is my bibliography. In a shorter form:  \bibliographystyle[unsrt]  \usepackage[backend= biber, style=numeric]{biblatex} \addbibresource{lit.bib} \begin{document}   ...  \newpage \printbibliography \end{document}   So thats basically what I wrote. I created a file named lit.bib in the correct form. If I wanna see the PDF version, I don't get an error. It doesn't print the bib at all. No idea what I'm doing wrong. I'd be vey thankful for any help!  Lisa :)

Running the minimal example  \documentclass{article} \usepackage{filecontents} \begin{filecontents*}{\jobname.bib} @ARTICLE{example,   author  = {Other, Anthony Norman},   title   = {Some things I did},   year    = {2014},   journal = {J.~Irrep. Res.},   volume  = {1},   number  = {1},   pages   = {1-10} } \end{filecontents*} \usepackage[backend=biber]{biblatex} \addbibresource{\jobname.bib} \begin{document} Hello\cite{example}. \printbibliography \end{document}   I get the warning There were undefined references.  I have read  and know that I need to run:   LaTeX Biber LaTeX   However, my editor is only set up to run BibTeX. How do I go about setting up my editor/IDE to be able to run Biber, and how do I run the LaTeX/Biber/LaTeX cycle?  Answers (sorted alphabetically by editor name)                    Answer guidelines   Each answer should be for one editor. If the editor is cross-platform, if possible give a single answer with notes covering the minor platform variations. Please edit the question to include new answers in the 'link list' Each answer should be 'stand alone', i.e. don't say 'It's almost the same as editor Y but ...' for the editor part Instructions for 'build tools' such as arara or latexmk are welcome but should explain how to set up the editor in question as not all editors allow simple addition of arbitrary tools


MY PHPMailer email goes to Spam for YahooMail and Hotmail, but not for Gmail. After running Port25's authentication verifier test to make sure my email settings were good these were the summary of the results:      Summary of Authentication Verifier    - SPF check: pass    - DomainKeys check:neutral    - DKIM check:neutral    - SpamAssassin check: ham   (Message me if you want the full details)   WHAT I'VE TRIED:    SMTPAUTH = TRUE DOMAIN NOT BLACKLISTED: voozlr.com Authentication Verifier Test Passed REMOVED ALL IMAGES REMOVED ALL CONTENT EXCEPT FOR BODY: TEST   I'm hosting my site and email server on Interserver.net, and they made sure everything is working from their end, but I still go to SPAM.      So what are the best practices for my PHP code to avoid the spam folder?  Someone please give me an example code or better yet edit my code to show me what SPAM free PHPMAILER code looks like.  PHP CODE:  $mail2 = new PHPMailer(); $mail2->IsMail(); $mail2->Host = "mail.mydomain.com";  $mail2->CharSet  = "UTF-8"; $mail2->SMTPAuth = true;  $mail2->Username = "name@mydomain.com";  $mail2->Password = "password1234";  $mail2->SMTPSecure = 'TLS';                       $mail2->Port = 25;                              $mail2->setFrom('support@mydomain.com', 'Support'); $mail2->AddAddress("$email"); $mail2->AddReplyTo('support@mydomain.com'); $mail2->WordWrap = 50;  mail($to, $subject, $message, $headers);  $mail2->Subject = "Testing";  $headers .= "MIME-Version: 1.0\r\n";  $headers .= "Content-type: text/html; charset=iso-8859-1" . "\r\n"; $headers = "From: " . strip_tags($_POST['admin@mydomain.com']) . "\r\n"; "Reply-To: support@mydomain" . "\r\n";  $message .= 'test'; $mail2->Body = $message; $mail2->AltBody = $message;  if(!$mail2->Send()) { echo "Message could not be sent. Please reload the page and try again. <p>"; echo "Mailer Error: " . $mail2->ErrorInfo; exit; }

This is a tricky one and I've always relied on techniques, such as permission-based emails (i.e. only sending to people you have permission to send to) and not using blatantly spamish terminology.  Of late, some of the emails I send out programmatically have started being shuffled into people's spam folder automatically and I'm wondering what I can do about it.  This is despite the fact that these particular emails are not ones that humans would mark as spam, specifically, they are emails that contain license keys that people have paid good money for, so I don't think they're going to consider them spam  I figure this is a big topic in which I am essentially an ignorant simpleton.


i'm dual booting Windows 7 and Ubuntu 14.04 in my laptop and i allocate 4 NTFS partition for Windows and one Ext4 partition for Ubuntu, when Ubuntu start it show all of my NTFS partition as devices, i need to prevent all access to my Windows partition inside Ubuntu.

I have two NTFS partitions that constitute a Windows 7 install. I am running Ubuntu and virtualize that Windows install off the physical disk. While the VM is working it could be disastrous if mount any of those partitions and make changes to them.  How do I prevent Ubuntu from mounting these partitions _at_all_?  Tried something along the lines of  /dev/sda none ntfs,ro 0 0    in /etc/fstab but that just gave me an error..  Thanks!


Consider the question, .  The answers say, "an elementary particle" and not much else. They don't actually answer the question. Moreover, the question is flagged as a duplicate of,  – the answers there don't tell me what a photon is either. Nor do any of the answers to  mentioned in the comments. When I search on , I can't find anything useful. Questions such as,  look promising, but bear no fruit.  say things like, "the photon is an excitation of the photon field." That tells me  nothing. Nor does the , which says:     The photon is the quantum of the electromagnetic four-potential, and therefore the massless bosonic particle associated with the electromagnetic force, commonly also called the 'particle of light'...   I'd say that's less than helpful because it gives the impression that photons are forever popping into existence and flying back and forth exerting force. This same concept is in the  too - but it isn't true. As , "Virtual particles only exist in the mathematics of the model." So, who can tell me what a real photon is, or refer me to some kind of authoritative informative definition that is accepted and trusted by particle physicists? I say all this because I think it's of paramount importance. If we have no clear idea of what a photon actually is, we lack foundation. It's like what :     Photons seem to be one of the foundation ideas of quantum mechanics, so I am concerned that without a clear definition or set of concrete examples, the basis for understanding quantum experiments is a little fuzzy.   I second that, only more so. How can we understand pair production if we don't understand what the photon is? Or the electron? Or the electromagnetic field? Or everything else? It all starts with the photon.   I will give a 400-point bounty to the least-worst answer to the question. One answer will get the bounty, even if I don't like it. And the question is this:    What exactly is a photon?

I am currently trying to learn some basic quantum mechanics and I am a bit confused. Wikipedia defines a  as a quantum of light, which it further explains as some kind of a .     What exactly is a quantum of light?   More precisely, is a quantum of light meant to be just a certain number of wavelengths of light (something like "1 quantum = a single period of a sine wave" perhaps?), or is the concept completely unrelated to wavelengths? In other words, how much is a single quantum?


In PHP there is a difference:  $var='text'; '$var' → $var "$var" → text   In some other languages:  'c' → single char "string" → multiple chars   and in Python?

According to the documentation, they're pretty much interchangeable.  Is there a stylistic reason to use one over the other?


I'm new to blender (3 days) and I've recently tried to make some cosmetic packaging for a toothpaste brand. I've been able to create the models to a decent extent, but when it comes to applying the logos, I am getting stretching and weird behaviour. I am planning on adding other parts of the packaging later, but before that, I need to understand how to fix this problem. I'm using a png with no background, and I've tried to UV unwrap and map the textures on. I've attached the file and a screenshot below if that's any help at all. Thanks for your help!

Is there a way to automatically unwrap my character? If not, is there a tutorial or something?


What is the difference between "like" and "=" ? For example:    def sequence     slug = title.to_param     sequence = Movie.where("slug = '#{slug}-%'").count + 2     "#{slug}-#{sequence}"   end   and     def sequence     slug = title.to_param     sequence = Movie.where("slug  like #{slug}-%").count + 2     "#{slug}-#{sequence}"   end

When using SQL, are there any benefits of using = in a WHERE clause instead of LIKE?  Without any special operators, LIKE and = are the same, right?


Can Anyone Help Me to Remove Sitename: from google Search results.   This is my real title name <title>Web Design & Web Development | Ixeun Software Solutions | Batticaloa</title> but google adds iXeun: Web Design & Web Development | Ixeun Software Solutions | Batticaloa from search results this is little bit confusing for me.   Please Search for site:ixeun.com on google so you will find my home page link root shows like above.

Apologies if the question is a repeated one but I couldn't find a solution for this.   I have following HTML code on the home page of my website.    <title>Sample title for illustrative purpose | example.com</title> <meta name = "description" content = "Here is an example of what a snippet looks like in Google's SERPs. The content that appears here is usually taken from the Meta Description tag if relevant."> <meta name = "keywords" content = "keyword1, keyword2">    Home Page Link
Sample Heading
   SERP shows following result:   Question: Why is example.com (the circled one in attached pic) is taken into account on SERP when it's not there in the title?


I am working with some data in which two component scores X and Y are added together to make a total score X + Y. Is there any known relationship between the correlation R for X vs. X + Y and the R for Y vs. X + Y?   I've played around a little bit, but I am not seeing anything except in the case where X and Y themselves are uncorrelated. (In that case, the R2 values sum to 1.)  ETA: With all due respect, this question is NOT a duplicate of the one already cited. I made abundantly clear that I am not talking about cases in which the variables have no correlation, which is a key feature of the other question. I am asking a much broader question.

Taken from  where Douglas Altman writes in page 285:      ...for any two quantities X and Y, X will be correlated with X-Y.   Indeed, even if X and Y are samples of random numbers we would expect   the correlation of X and X-Y to be 0.7   I tried this in R and it seems to be the case:  x <- rnorm(1000000, 10, 2) y <- rnorm(1000000, 10, 2) cor(x, x-y)  xu <- sample(1:100, size = 1000000, replace = T) yu <- sample(1:100, size = 1000000, replace = T) cor(xu, xu-yu)   Why is that? What is the theory behind this?


set Prompt=normal in /etc/update-manager/release-upgrades.

On a Lenovo laptop, I want to upgrade from Ubuntu 18.04 to Ubuntu 18.10 (budgie).  When I select upgrade on the update manager, the dialog box disappears and nothing happens. The upgrade doesn't start.  Note- I went through the same procedure this morning on my other laptop and Ubuntu successfully upgraded.   do-release-upgrade fails to upgrade and throws this error:  Please install all available updates for your release before upgrading.   What can I do to upgrade the system successfully?


How should I say this?        The color of the chair and the table ...   The color of the chair and of the table ...      Why should that option be used (apart from being the correct one)?

I worked and did not play. I worked and not played. ?  For some reason, when the ellipsis is used after the simple past form of the verb with no "to be" used before it, it just sounds weird to me. Is there something wrong with it, or is it just that it is not idiomatical? Or am I the one who's wrong?  I had to control myself and not cry in front of her.  I always thought that second part has been used independently and not connected to the "had to" part, for I thought there should be additional "to" like this I had to control myself and had to not cry. Or at least this: I had to control myself and to not cry in front of her. (It doesn't sound very idiomatic... is it acceptable?) Is the "to" deleted? If it is, why is that? And also, when I was trying to find the answer for this question, it was clear that everybody was asserting only the parallel form should be allowed for the ellipsis after the coordinating conjunction. For example:  Sarah is [a CEO] and [proud of her job]. - NP + AP Is Jim [conservative] and [a closet Republican]? - A + NP He is a crazy man and may drink a lot. -NP+V  These (only the three sentences directly above it) are from Wikipedia, and not regarded as being incorrect. But looking up at the other websites, I find that they say that it is wrong, even though many people, including me, use it this way. They say that it should be parallel like this:  Sarah is [a CEO] and [a person proud of her job]. - NP + NP  Is it supposed to be always parallel?


When we study topology, we typically study topological spaces and continuous maps between them. From a categorical perspective, this is "wrong," because continuous maps are not the structure preserving maps. If "the structure of a topological space" is it's topology (i.e., it's open sets) then it seems like the natural choice for the definition of a structure preserving map would be an open map. So why do we like continuous maps instead of open maps?

Recently, someone mentioned to me that given a function $f: X \to Y$ there are two natural functions between the powersets $P(X)$ and $P(Y)$. Namely $f: U \subset X \mapsto f(U)$ and $f^{-1}: V \subset Y \mapsto f^{-1}(V)$. Then if we consider maps between $P(P(X)), P(P(Y))$, each of the above maps induce two more, so there are four natural maps.  Thus, it seems on the face of it like there are four natural choices for morphisms of topological spaces (since a topology on $X$ is an element of $P(P(X))$). Why is it that continuous functions are the morphisms we choose and not one of the other four maps?  I understand that the theory we get from taking continuous functions as morphisms is incredibly rich and so this alone provides adequate justification. However, I am looking for a different sort of justification along the lines of "is there some property of continuous functions that immediately suggests they are the 'right' choice of morphisms between topological spaces?".


I am trying to callout to the Salesforce Metadata service (ApexMDAPI) using Named Credentials.  My goal is to use this credential with configuration in a managed package.  Here's my use case: I'm putting together a setup script for a managed LWC application. My app is using custom metadata which must occasionally be changed. (A series of configurable lists, to be specific) To do that, i need a first class sessionId or a Named Credential. (I'd rather not have a whole bunch of VF pages to do that part, and since Lightning doesn't provide the first class sessionId, I think I'm stuck with the Named Credential approach. After the pkg is installed, I have a VF screen which creates the Named Credential, so that Lightning components can use the Named Cred callout from lightning  I have successfully created the ConnectedApp/AuthProvider/NamedCredential records entirely with apex/Visualforce.  The problem is that since I created the NamedCredential with apex, the initial authentication flow hasn't been triggered, and this can't be used in Callouts.  If I simply click "Edit"/"Save" on the new NamedCredential, then the auth flow will be triggered, and the credential works perfectly.  Is there another way that I can trigger this initial flow without requiring the user to edit/save the Named Cred?  In case you're wondering why I didn't just include the Named Credential in my original package, I've already tried that.  The problem with that is the endpoint for the Named Credential still points to the org where the package was assembled.  Editing the endpoint in the new org results in an unuseable Named Credential.

I use the  to create an AuthProvider and NamedCredential after the installation of my managed package app. MetadataService.NamedCredential cred = new MetadataService.NamedCredential(); cred.fullName = 'MyCred'; cred.label = 'MyCred'; cred.allowMergeFieldsInBody = false; cred.allowMergeFieldsInHeader = true; cred.authProvider = 'MyKeycloak'; cred.generateAuthorizationHeader = true; cred.oauthScope = 'api refresh_token'; cred.principalType = 'NamedUser'; cred.protocol = 'Oauth'; cred.endpoint = apiEndpoint.trim();  The problem is the Authorization is still in Pending status as a user seems to manually Edit and Save the Named Credential to trigger it. Is there a way I can trigger that by my code when I insert the NamedCredential?


I am beginning with the mount and Linux file-system concept. Just as a simple test I have mounted a share from my server(VM) to the client (VM). Things are fine, it is mounted and I could work on it as on a local file system.  And then I tried mounting a share from my physical machine to my client(VM), things are also went fine. But the place where I have been stuck is when I see the color of the shares that I have mounted. Share that mounted from VM to VM is in green and the one I have mounted from physical to VM is look like a normal directory. I haven't used any special option switches while mounting. I wonder what this all about the color thing when mounting, can anyone shed some light?[my distro is debian]    As you could see 173_VM is file share mounted from VM and next is file-share mounted from physical machine. The VM one is in green.

There are two directories shown by 'ls'.  Normally directories anywhere are blue on black background.  But the first one is blue on green and impossible to read.  Why is this?  How to make it blue on black, or at least something light on something dark?  This is on Ubuntu 12.04, using bash in Gnome Terminal.  In Konsole, the blue is slightly darker, and possible to read, though could be way better.


How do i calculate no of caps required to replace a battery. If i am given a voltage of battery and capacity of battery and datasheet of required capacitor

I have a 1.25V 2Ah battery and I'm trying to calculate a equivalent capacitance with rated voltage of 2.7V for each of those batteries. This is what I did:   Work of Battery = \$1.25V \cdot 2A \cdot 3600s = 9000J\$  From the capacitor work equation:  $$W = 0.5 \cdot C \cdot V^2$$  $$9000J = 0.5 \cdot C \cdot 2.7V^2$$  $$C=2469.1358F$$  Is this correct?


Find the value of the expression $\tan\frac{\pi}{16}+\tan\frac{5\pi}{16}+\tan\frac{9\pi}{16}+\tan\frac{13\pi}{16}$    I identified that $\frac{\pi}{16}+\frac{13\pi}{16}=\frac{5\pi}{16}+\frac{9\pi}{16}=\frac{14\pi}{16}$ $\tan(\frac{\pi}{16}+\frac{13\pi}{16})=\tan(\frac{5\pi}{16}+\frac{9\pi}{16})$ $\frac{\tan\frac{\pi}{16}+\tan\frac{13\pi}{16}}{1-\tan\frac{\pi}{16}\tan\frac{13\pi}{16}}=\frac{\tan\frac{5\pi}{16}+\tan\frac{9\pi}{16}}{1-\tan\frac{5\pi}{16}\tan\frac{9\pi}{16}}$ But i am stuck here.Please help me.Thanks.

By looking through an book, I found this interesting series  To prove that:  $$\tan(\theta)+\tan \left(\theta+ \frac{\pi}{n} \right) + \tan\left(\theta + \frac{2\pi}{n}\right) + \dots + \tan \left (\theta + \frac{(n-1)\pi}{n} \right) = -n\cot \left(\frac{n\pi}{2} + n\theta \right)$$  I have tried the Gaussian pairing trick and using:  $$\tan A + \tan B = \tan(A+B) (1-\tan A \tan B)$$  And  $$\tan A \tan B = \frac{\cos(A-B) - \cos(A+B)}{\cos(A-B)+\cos(A+B)}$$  However I could not do anything of great use.  I also considered perhaps roots of unity of:  $$z^{2n} = \cos \theta + i\sin \theta$$  But that grew to no real use, but it may be an idea for others.  I know I can sum an arithmetic series of the arguments for the cosine and sine functions but I cannot find a source on the internet about the tangent function.   Thank You.


I have an old router with a 12v 1.5a rating, and its power supply died so I'm using a 12v 1.2a power supply.  I have a MIDI keyboard with a 9V 500mA rating and I have a 9V 200mA power supply and one with a 9V 1A rating.  If I don't have the exact amperage, should I use higher or lower?

Power supplies are available in a wide range of voltage and current ratings.  If I have a device that has specific voltage and current ratings, how do those relate to the power ratings I need to specify?  What if I don't know the device's specs, but am replacing a previous power supply with particular ratings?  Is it OK to go lower voltage, or should it always be higher?  What about current?  I don't want a 10 A supply to damage my 1 A device.


I need to solve this:  $$z^3 + \overline z = 0$$  how should I manage the 0?  I know that a complex number is in this form: z = a + ib so:  $$z^3 = \rho^3\lbrace \cos(3\theta) + i \sin (3\theta)\rbrace$$ $$\overline z = \rho\lbrace \cos(-\theta) + i \sin (-\theta)\rbrace$$ but how about the 0?  EDIT: ok, following some of your comments/answers this is what I have done:  $$z^3 = - \overline z$$ $$\rho^3\lbrace \cos(3\theta) + i \sin (3\theta)\rbrace = \rho\lbrace \cos(-\theta) + i \sin (-\theta)\rbrace$$  So $$ \begin{Bmatrix} \rho^3 = \rho\\  3\theta = -\theta + 2k\pi \end{Bmatrix}$$ $$ \begin{Bmatrix} \rho^3 = \rho\\  2\theta =  2k\pi \end{Bmatrix}$$  $$ \begin{Bmatrix} \rho = 0 or \rho = 1\\  \theta =  k\frac{\pi}{2} \end{Bmatrix}$$  is this the right way?

I'm trying to find the complex roots of $z^3 + \bar{z} = 0$ using De Moivre.  Some suggested multiplying both sides by z first, but that seems wrong to me as it would add a root ( and I wouldn't know which root was the extra ).  I noticed that $z=a+bi$ and there exists $\theta$ such that the trigonometric representation of $z$ is $\left ( \sqrt{a^2+b^2} \right )\left ( \cos \theta + i \sin \theta \right )$ .  It seems that $-\bar{z} = -\left ( \sqrt{a^2+b^2} \right )\left ( \cos (-\theta) + i \sin (-\theta) \right )$  However, my trig is pretty rusty and I'm not quite sure where to go from here.


I'm working on a    Ubuntu 18.04.2 LTS. I wanted to upgrade R but I constantly get stuck. I've entered   sudo gedit /etc/apt/sources.list   Where I add   deb https://cloud.r-project.org/bin/linux/ubuntu bionic-cran40/    and saved.  Then I got this error message:     ** (gedit:27981): WARNING **: 21:44:53.588: Set document metadata failed: Setting attribute metadata::gedit-position not supported   When I tried previously it worked and indeed I came here for a problem (public-key not found) which I encountered later in the process (after typing sudo apt-get update). Now I'm stuck even earlier..:((  I didn't find any thread with answers about this issue. Can someone help me? Thanks

When using sudo powers and calling gedit the top level menu with File Edit View Search Tools Documents Help is missing.  If I create user ID root and sign in once and call gedit will it create the necessary user configuration files that might fix this?  Will this also make the annoying error messages go away whenever I use sudo, gksu or pkexec as a regular user with elevated privileges togedit ?  Will there be other benefits with Nautilus and other Gnome derivative Ubuntu applications?  NOTE: by sudo powers you can google pkexec gedit 3.5k hits, gksu gedit 40k hits or sudo gedit 500k hits. I'm in the minority using the first method but I believe it will become the standard in Ubuntu 17.04.    June 12, 2017 Update Here are a list of errors you get when using pkexec gedit:  (gedit:13003): Gtk-WARNING **: Calling Inhibit failed: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files  ** (gedit:13003): WARNING **: Set document metadata failed: Setting attribute metadata::gedit-spell-enabled not supported  ** (gedit:13003): WARNING **: Set document metadata failed: Setting attribute metadata::gedit-encoding not supported  ** (gedit:13003): WARNING **: Set document metadata failed: Setting attribute metadata::gedit-position not supported   On this  there is a commitment to fix these distracting messages as of June 5, 2017. No indication is given for when the fix will be upstream nor if the functionality will be implemented or the error messages will simply disappear.  Note the bug report was filed over a year ago and over that time it only effects 18 people.


I changed the default login screen wallpaper to a custom one as well as the desktop background to a another custom one(basically I have two different backgrounds one for login screen and one for desktop).   Unfortunately recently it started to act weird. At the startup the login screen wallpaper shows for like half a second and then it automatically changes to the desktop wallpaper before I even log in. I don't use anything else to change the backgrounds apart from unity tweak tool and to change the login screen I replaced the default file in /usr/share/backgrounds.   It's a minor problem but I cannot solve it myself and need some help.   Thanks in advance!

I would like to set the wallpaper in the login screen (Unity Greeter), how do I do that?


Some users are logging into database servers locally, opening SSMS and logging in to SQL Server using SQL logins to run queries.  How can I find the AD user that logged in to SQL Server using a SQL login on the local database server using SSMS?

Is it possible to find out who used a SQL-Server login?   Let's assume we suspect a person to abuse a SQL login that is supposed to be used by an application only to logon to SQL-Server. Is the domain user who used the SQL login logged anywhere, so that we can make a conclusion who used it?


it's been a few times now that my system completely freezes up (Ubuntu 16.04) where my mouse and touch pad seizes to work. The keyboard also doesn't respond. All that helps is to power down and restart via the power button.   Note: may it be that low RAM is the root cause? I have an Asus with 2GB RAM and 500GB HDD (Just asking)

My system freezes completely at random, frequent intervals. I started to have the same problem in Ubuntu 14.04 but after recent upgrade to 16.04 there is no improvement, in fact it seems worse.  When it happens, it's impossible to do anything. I've tried everything in this thread:  but nothing works, I have to hard reset. I have read all the system logs and journalctl but there is never any information that could help diagnose the problem.  This is a dual-boot system with Windows 10 and there's no problem there, so it's not defective hardware.  My laptop has an Intel Bay Trail processor (Pentium N3540)


"it was ... interesting to see these (1) quite deprived areas (1) erm  (.)"  Is quite here being used as an quantifier and is the noun "areas" countable in this context? It sounds to me like 'quite' is also used as a filler but I'm not sure. For example, when girls colloquially add unecessary "like" and "really" in their phatic talk.

The adverb "quite" has the following meanings :     1: wholly, completely ("not quite   finished")      2: to an extreme : positively "quite   sure" —often used as an intensifier   with a "quite a swell guy" "quite a   beauty"      3: to a considerable extent : rather   ("quite near")   My understanding is that #1 and #2 conflict with #3. For example, when you say "She's quite right", do you mean "She's completely right" or "To a considerable extent, she's right"? Notice that in the latter case you're not saying that she is completely right.  Another example is "I'm quite sure". Does it necessarily mean "I'm completely sure"?   Does the word really have conflicting meanings that can possibly cause ambiguity? Or am I missing something?


I am currently in my 2nd year in a PhD and going to master out in May. Should I put "leaving PhD" on my resume? Or just Masters? My field is in Computer Science where mastering out is quite common.

I am not happy with my PhD program, and after several years I am graduating with a master's this month. I earned the M.S. along the way as a PhD student, but have never formally requested it before this semester. What is the best way to indicate this situation on a CV or resume? I don't want to put just M.S. because then it looks like it took me a really long time to get a master's and I can't put that I am a PhD student because I no longer am.  Right now, I am thinking something like  M.S. in <field>, <University>, May 2016 PhD student in <field>, <University>, Aug. 2011 - May 2016 B.S. in <field>, <Undergrad University>, Aug. 2007 - May 2011   Would that be clear what's going on? Alternatively, should I list PhD above M.S. even though I didn't complete it? Should I list both M.S. and PhD in same line since it is the same university and span of time?


I've recently started a PhD position in a university and I figured out that many aspects deject me. At the moment I'm employed in a test phase of a few months, and this has led me to think of leaving this position if it didn't fulfil me by then. With that in mind,  Is it ethical/professional/acceptable to ask my references for additional recommendation letters, again, for the new positions I'm going to apply to? Is a sign of lack of commitment and interest (and therefore, unprofessional)?  I appreciate your opinions.  PS: Even though I have accepted this position, it never was among my top choices. In fact, my decision was very much affected by the situation of COVID in my country and the market recession. UPDATE The main reasons unprofessionalism strikes my mind are the following. I hope it clarifies my situation more.  I'm in the very early days of my PhD, the transient phase so to speak. So any extrapolation of my current situation to the future isn't reliable. I'm afraid that I'm making my mind during this transition time, before adjusting myself or tasting the research as much as I should.  As far as I can feel, the non-academic aspects of my unhappiness outweigh the academic part; For instance, the cold environment of the campus and the city, the depressing atmosphere of the only accommodation I could find, as well as my flatmates (please look at PS2) who are desperately are looking for jobs in the wakes of the pandemic, all transfer a sense of stagnation to me. Although some of these issues can be solved, I believe they need an immense amount energy and time, probably comparable to the effort I need to put on my research.  I accepted this position with one vital side goal in mind, which (to be honest) is as important for me as the PhD degree if not more: learning the local language (until B1 level). Learning a new language is though, especially alongside a PhD. I know it needs extra focus and perseverance. But with all I have to face (summarized in the previous number), and knowing my personal mental capacity, I'm seriously sceptical about being able to achieve this.   I believe these are decent arguments on a personal level, but maybe not academically. I'm afraid that Academic institutes may find this chain of reasoning unsatisfactory, a set of excuses, or a sign of unreliability. As I'm barely a researcher at this point, I'd be grateful if you can shed more light on these arguments and resolve their (lack of) pertinence to the academic world to me, as an experienced outer observer.  PS2: My flatmates are good people. However, I'd rather like to be surrounded by people who are trying to push forward a meaningful protect with passion. That kind of people whose perseverance inspires others. And I'm not talking about superman; For me, any other PhD candidate is a good example of such a group.)

I've heard of people transferring between graduate schools because of their advisor moving to another school and taking their students with them.   Do students ever transfer for other reasons? If a student isn't happy at the school they choose, could transferring be an option? Presumably they would frame it as something positive such as "turns out I really want to work with Professor X" rather than "I hate my school", but does this ever happen? Is there a certain timeframe in which this is possible? (Assume it's a 5 year PhD program.)  If the answer varies by subject please mention the subject in your answer.  (Context: many friends have told me that if it turns out I'm not happy with my choice, I can always transfer. My impression is that this is actually difficult since many schools don't accept transfer students and in any case not being able to stick with a program looks bad -- but I don't have evidence either way so wanted to ask people who are in academia. Of course the ideal would be to pick a school one is happy with in the first place!)


A mod changed a few spellings on one of my questions that I don't agree with. Where is the best place to discuss this with him?

I know  is actually trying to be helpful by formatting code, but it appears that the first line of code is always indented incorrectly (maybe it's just my OCD). After about three of their edited posts corrections, which somehow always got approved, I ended up going through just the first page of approved edits this user made, and corrected the same problem.   I don't think it would be correct to add a comment directed at the editor asking them to correct this issue. I don't see any way to flag a user for moderator review, or have the moderator contact them. I don't see a method to flag an edit for review. and I don't see any other way to contact this user to help them correct the problem and save a lot of people extra work.   What is the solution to this?


It seems like such a simple questions but I cant find any resource regarding it  In C/C++ , it means to store the read in a value from command prompt and store it inside a variable ,   How about in Shell Programming?

Could someone explain to me the difference between > and >> when using shell commands?  Example:  ps -aux > log ps -aux >> log   It seems the result is the same either way.


I read this book several years ago. All I remember about the plot is that teens (who have special abilities) are part of an organization run by gods. There's another group that is trying to defeat/usurp the gods. The main god has two sons. One is mortal but has been given the gift of immortality and the other, Matt I think, is naturally immortal. There is a love triangle between Matt, his best friend (also a member of the god's organization), and Rachel, who betrays them to the evil-doers. Matt's sister ends up falling in love with the mortal son of the god. There is some time travel. I know it's a long shot that anyone has heard of this novel but if you could help me out I would be eternally grateful.

This has been driving me crazy. I know I read this book/books (possibly a trilogy) around the same time as reading Sabriel etc and the Windsinger trilogy. I don't remember a lot but I think it was about an immortal man (Sure that his name started with A) who had bright blue or purple hair (I remember a line about how hair constantly changes colour but only a few people live long enough to see it go past grey). I think he recruits young people and sends them places to do missions (can't remember if its time travel or different universes etc) It ends with one of the girls falling in love with the immortal man and deciding to stay with him. I know that this isn't a lot to go on but if anybody knows what this is, I will be very thankful. Oh and I think one of the books was called Key to the Door or something similar?


I am looking for advice on the best texts to remind myself how to do math. I am 35 and an attorney (patent) but was once very good at math (best in my high school, 800 SAT) but then stopped completely after taking Calculus in college as that was all I needed for the MCAT. How I ended up an attorney is a long story...  Anyway, as I get older, I am drawn more and more to understanding simply for understanding's sake. I always enjoyed math because it required a lot of mental effort that led to a real, correct answer. I've gone back to math now and then for fun, took a class at a local college years ago but now I've decided I want to go back again and pick up where I left off but focus more on a rigorous understanding and not just the computational Calculus I took in high school and again in college. I searched online, including reading lots of threads on this site, and ultimately went with Apostol's Calculus Vol 1 and planned to look at the notes in MITs 18.014 class (Calculus w/ Theory).   Long story long, I received the book, got to the first proof in the introduction and realized I have forgotten just about everything. My arithmetic skills are still excellent as even as an attorney those get used day to day, but he might as well have been speaking Greek when he proved the area under the curve/method of exhaustion.  So, hence why I am here. :) I want to find the best book/books to re-ground myself in the mathematics needed to make a go at a rigorous study of calculus. There is no career goal in mind here, I just want to do it for the sake of it.   I came up with several ideas from reading threads here or reading Amazon reviews, including:  Gelfand (Algebra and Trigonometry)  Lang (Basic Mathematics)  Simmons (Precalculus in a Nutshell) Velleman (How to Prove It)  and I have Euclid already on the shelf, hah.  I am a perfectionist, fortunately or unfortunately, so if I am going to go through the effort, I want to do it well and with full understanding, not just blow through some Kahn Academy videos and on to Calculus. But, I also need to be efficient.   Does the list above make sense? Are they redundant or is anything missing? Any other recommendations?  Thanks very much.

i have missed pre-calculus knowledge in my school but i was good at maths, and now i am a computer science student, i am feeling bad being bad in maths, so i am looking for the best Pre-Calculus book, i love maths, i need the right well of precalculus books.


In latex, the command \today displays today's date.  Consider that I write something like: Updated news: \today. It appears like     Updated news: Saturday, October 24, 2015   After a while, when I recompile the document, say 4 days later, it will say     Updated news: Thursday, October 29, 2015   at the very same line. Is there a way to make a \today static? In other words, I'd like my document like a blog. When I insert a date, I want that date to stay.  How can I do this?

When I write my notes, (I actually use lyx but that does not matter) I like to add a header with the name of file and the date the file was compiled. This I do using fancyhdr package and   \pagestyle{fancy} \lhead{\texttt{\jobname}} \rhead{\textsf{\today}}   (to tell the truth in lyx I have to use \jobname.lyx, but, again, this does not matter).   The point is that it would be much more useful (at least for me) to be able to print the date when the file was first created. Is there a way in TeX/LaTeX to access the time information of a latex file? I can understand the answer might be OS dependent. I am actually using a linux distribution. I looked in many other forums/FAQ but could not find the answer so far.


The default PID max number is 32768. To get this information type:  cat /proc/sys/kernel/pid_max  32768   or   sysctl kernel.pid_max kernel.pid_max = 32768   Now, I want to change this number... but I can't. Well, actually I can change it to a lower value or the same. For example:  linux-6eea:~ # sysctl -w  kernel.pid_max=32768 kernel.pid_max = 32768   But I can't do it for a greater value than 32768. For example:  linux-6eea:~ # sysctl -w  kernel.pid_max=32769 error: "Invalid argument" setting key "kernel.pid_max"   Any ideas ?  PS: My kernel is Linux linux-6eea 3.0.101-0.35-pae #1 SMP Wed Jul 9 11:43:04 UTC 2014 (c36987d) i686 i686 i386 GNU/Linux

What is the maximum value of the Process ID?  Also, is it possible to change a Process ID?


A question in my math book is: "Use mathematical induction to show that:  $$e^x>1+x+\frac{x^2}{2!}+...+\frac{x^n}{n!}$$  if $x>0$ and $n$ is any positive integer."  Apparently the solution involves applying the Mean Value Theorem on:  $$g(t)=e^t-1-t-\frac{t^2}{2!}-...-\frac{t^{k+1}}{(k+1)!}$$  Then:   $$\frac{g(x)}{x}=\frac{g(x)-g(0)}{x-0}=g'(c)$$  Then it states that $g'(c)$ is positive.  QUESTION 1: why is $g'(c)$ positive?  QUESTION 2: how would one answer (in small understandable steps) the original question of my math book? I don't fully understand the method used.  Thanks!

Show that if $n \geq 0$ and $x>0$, then   $$ e^x > 1 + x + \frac{x^2}{2!} + \dots + \frac{x^n}{n!}.$$  Not sure where to get started with this induction proof.


I am looking for a term for someone who is purposefully not learning information - usually bad information. Goes hand in hand with people who want to "hide their head in the sand" or have the "wool pulled over their eyes"

What would you call a person who doesn't want to learn new things and even maybe thinks that this is unnecessary since he knows enough already?  An ignorant person?


First of all, I would like to note that I have read similar topics in CrossValidated but I am not fully satisfied.   I have a dataset which consists of an $N\times M$ binary matrix. 1 means that an action is performed and 0 that it is not.   I apply PCA to the dataset and surprisingly get very good results, especially when I reduce it to only two dimensions. I am looking for the intuition behind performing PCA on such a dataset (i.e. where each attribute contains categorical data; you can give whatever example you think is more understandable) and whether a more appropriate technique can be applied. I am working with MATLAB and I need the data in a clustering friendly form.

In today's pattern recognition class my professor talked about PCA, eigenvectors and eigenvalues.   I understood the mathematics of it. If I'm asked to find eigenvalues etc. I'll do it correctly like a machine. But I didn't understand it. I didn't get the purpose of it. I didn't get the feel of it.        I strongly believe in the following quote:     You do not really understand something unless you can explain it to your grandmother. -- Albert Einstein   Well, I can't explain these concepts to a layman or grandma.   Why PCA, eigenvectors & eigenvalues? What was the need for these concepts? How would you explain these to a layman?


How can I prove that: $$\frac{1}{2} \left(3 n^2-2\right) \left(3 n^2-1\right) \left(3 n^3-3 n+1\right)\in\mathbb{N}$$ When $n\in\mathbb{N}$?

If $x$ is positive integer, prove that for all integers $a$, $(a+1)(a+2)\cdots(a+x)$ is congruent to $0\!\!\!\mod x$.  Any hints? What are the useful concepts that may help me solve this problem?


I am trying to get whether the author has posted within the last 30 days but this returns TRUE even if the author hasn't posted within the last 30 days.        <?php $args = array( 'post_type' => 'post', 'post_status' => 'publish', 'author' => get_current_user_id(),  'date_query' => array(array('after' => date('Y-m-d', strtotime('-30 days')), 'inclusive' => true,),) , 'fields' => 'ids',); $wp_posts = get_posts($args); if(count($wp_posts)) : ?>
Author posted within the last 30 days
       <?php else : ?>
Author did not post within the last 30 days
       <?php endif; ?>   Not sure what I am doing wrong here.

Is is possible to check whether an author has posted in the last X days?  I am currently using this function to determine whether he has posted at all.  $args = array(     'post_type'  => 'your_custom_post_type',     'author'     => get_current_user_id(), );  $wp_posts = get_posts($args);  if (count($wp_posts)) {     echo "Yes, the current user has 'your_custom_post_type' posts published!"; } else {     echo "No, the current user does not have 'your_custom_post_type' posts published."; }


Update (Clarification) I ordered this PC from a very reliable store. I told them what parts I want (CPU, GPU, chassis, etc.), and they assembled it. Since I did not request an OS, they made sure that I'm aware that an OS is not included in the order. The PC arrived without any boot record, as expected. Even if the assemblers connected the machine to the internet, Windows was not installed, so no activation could happen upon assembly.  I bought a brand new desktop PC; it was assembled from all brand new parts. I created a Windows 10 (20H2) installation media using the tool from Microsoft's website. During the installation I clicked on "I don't have a product key" to skip activation. Now, on Licensing it shows me that it is "activated with a digital license". Executing slmgr /xpr results in "the machine is permanently activated". It really bugs me. How is this possible?

If you activated a free upgrade to Windows 10 or bought and activated   Windows 10 from the Microsoft Store, you have a digital license for   your device. This means you can reinstall the same edition of Windows   10 that your device has a digital license for without entering a   product key. During reinstallation, if you’re asked to enter a product   key, you can skip this step. Windows 10 will automatically activate   online after the installation is complete.   source:   Does MS digital license 'fingerprint' hardware information  during the free upgrade / activation and store it (at Microsoft) , so that the next re-install queries MS for the fingerprint and activates Windows 10?  Thought the disk drive may change, I expect that none of the other fingerprinted hardware will change.


I  this phrase:     So what is it about habits that makes something like biting your   fingernails so hard to stop, while making something like running a   couple half marathons per week possible? There’s three things to know   about why habits develop whether you want them to or not.   Is that correct (in formal English/grammar)? Should not we write There are three things ... instead?

It seems I put a   Bounty assigned by outside party, two lengthy, reference-citing answers, one "-1" (awarded the bounty), one "-2", two others scored "0" and "-2" respectively, the answers suggesting one or the other is correct, 73 comments and no consensus so far - and me, as the asker, lost without a clue what to think of the answers anymore -  this is no longer "Learners' Level" question, so I thought I'd bring it here and hear what the experts have to say.    Original question:  Plurality of verb depending on plurality of list elements  An edit was suggested to my sentence.     There was were an orange, some grapes, two apples and a small pile of cherries on the plate.   In my native language plurality of the verb always follows plurality of the first element on the list. There were an orange,... sounds awkward to me, no matter what follows up. My simple solution was reordering:     There were some grapes, an orange, two apples and a small pile of cherries on the plate.   But that's not the first time I faced this situation and I'd like to know what the rules of grammar say about that - was my editor overzealous or am I trying to copy rules of my language that don't apply in English?    Someone linked a  for negatives, where the situation is more clear-cut ("There is no..."). Same applies to connection with "or" apparently, per accepted answer there. Still, nothing for "and".  It seems there is a consensus that in that if the verb goes after the list, it will be plural.     an orange, some grapes, two apples and a small pile of cherries were on the plate.   There doesn't seem to be clear consensus for:     On the plate { was | were } an orange, some grapes, two apples and a small pile of cherries   Adding more to the confusion is the abbreviated form: "There's"     One last note. In North America, at least, there is a widespread use of using a singular form like "there is" and "there was", without regard for the subject item or items, and this "there is" is often shortened to "there's":           There's three apples on the table!      Could you please clarify this mess?


Find all integers $a$ and $b$ such that: $$|a^2 -2b^2|=1$$ The solutions to this equation are related to the units of the ring $\mathbb{Z}[\sqrt{2}]$.

How can I show that the units $u$ of $R=\mathbb Z[\sqrt{2}]$ with $u>1$ are $(1+ \sqrt{2})^{n}$ ?   I have proved that the right ones are units because their module is one, and it is said to me to do it by induction on $b$ and multiplication by $-1+\sqrt{2}$. I have already shown that the units of this ring has norm $1$ and all the numbers with norm $1$ are units, this may help.


I would like to upgrade to Ubuntu 15.04 from Ubuntu 14.04.2 LTS. I went in the terminal, edited the /etc/update-manager/release-upgrades file, and set the prompt to normal. I went back into the terminal, and ran the command sudo do-release-upgrade -c, and this is the output:  Checking for a new Ubuntu release  New release '14.10' available. Run 'do-release-upgrade' to upgrade to it.   How can I upgrade to 15.04 without going to 14.10?

I am currently using Ubuntu 10.04. I know there is a 10.10 release, but can I upgrade directly to 11.04? Could you walk me through the steps please?


I was wondering if someone could help me out with the following question. I bought a ticket New York - Zurich - Vienna - Lviv (Ukraine). I read online on Swiss immigration website the following information (actually your website states the same):  If you a a permanent resident of the United States (which is my case), you can travel through Schengen airports (I read specifically about Swiss airports) without transit visa, regardless of your citizenship.  I am a Ukranian but I have the old non-biometric passport, which still should have been fine, since as a US permanent resident, I can travel through Swiss airports without a transfer visa (I don't have to leave the Schengen zone inside the airport.  In New York airport, I was denied boarding. I spoke with 2 supervisors and they all said the same: if you are doing 2 transfers in the Schengen zone, you have to have a transit visa, with no exemptions. I showed them 2 websites including the Swiss immigration and was told it's not the information they would acknowledge.  I still think I was right and that exemption rules should apply to me. I ended up buying another ticket and missing Christmas dinner with my family. Anyone with any suggestions, please help!

I was flying from Kiev through Munich and Frankfurt to US. In Kiev I was refused a registration for the flight by airport official due an absence of Schengen visa. I had also just a carry on language, no check in. I presented my green card, but he said it did not matter. I had to buy another ticket, which was expensive, directly to USA. Was that a correct action of the official?


I have a 64bit processor, but just installed ubuntu 18 32bit, how can I quick update the OS into 64bit, no need re-install from scratch? Thanks a lot!

I've got a 32-bit Ubuntu installation running on 64-bit hardware. Now that , I would like to switch to 64-bit without having to reinstall the OS.  This is one of the :  Shawn installed his system using the 32-bit version of Ubuntu, but his hardware is 64-bit and he wants to switch over. He manually installs the amd64 versions of dpkg and apt, replacing the i386 versions and changing which architecture is used as the default; then he installs the amd64 ubuntu-minimal package; then he installs the amd64 ubuntu-desktop package. Over time the remaining i386 packages are replaced automatically on upgrade.  However, when trying to follow the instructions in there, I cannot find any 64-bit version of dpkg or apt.  Did this user story got implemented in a different way in the final spec, or do I need to do something differently?  In short, how can I switch my 32-bit installation to 64-bit?


It's so easy to talk about "deciles" as if they were groups of observations that fall between the , i.e., "any of the nine values that divide the sorted data into ten equal parts." But that raises the question, what are the names of those parts?  To make this less subjective, I am requesting notable instances where bins derived from quantiles have been named in literature. What were they called?

The top 25% is the top quartile. The top 10% is the top decile. The top 1% is the top percentile.  Is there an equivalent for the top 0.5%  i.e. 1-in-200?


I am working on a logo.whenever i am shrinking the vector it seems like stroke has increase,but actually it haven't. if any body can help me out here.  Thanks.

I have this logo with two ellipses and multiple line segments.    The ellipses have 5pt strokes on them, no fill and the line segments are 3 pt, no fill. I placed the .ai file into another file and tried to resize it down to fit a business card, only to come upon this:    Now the shapes look like they have twice the stroke that they had before. Thanks in advance for any help!


I'm currently making a project that finds percentage and so on on numbers. However, when I made the if statement to determine what processes to carry out based on the user input, it skips over to the final else statement even if the input matches the if statement. Here is my code.  public class Percentage { public static void main (String[] args){     Scanner input = new Scanner(System.in);     System.out.println("Enter 'a' if you want to find a percentage of a given number.");     System.out.println("Enter 'b' if you want to find how much percent of a given number is a certain number.");     String choice = input.nextLine();       if (choice == "a"){         System.out.println("Enter the number.");         float numA = input.nextFloat();         System.out.println("Enter what percentage of the number you want to find.");         float perA = input.nextFloat();         float decA = perA * 0.01F;         float outA = numA * decA;         System.out.println(perA + "% of" + numA + "is: " + outA);     } else if (choice == "b"){         System.out.println("Enter the main number.");         float mainB = input.nextFloat();         System.out.println("Enter the number whose percentage of the main number you want to find.");         float minB = input.nextFloat();         float quoB = minB/mainB;         float perB = quoB * 100;         System.out.println(minB + "is" + perB + "% of " + mainB);     } else {         System.out.println("Invalid answer.");     }      input.close(); }  }   When I run the program and input either a or b, it goes straight to the else statement outputting "Invalid answer." What's wrong in my code?

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


I like the elementary OS terminal emulator quite a lot and I'd love to have it on my main machine, which is running Ubuntu 15.04 Vivid.  Is it possible without compromising Ubuntu's stability?

Is it possible to install Pantheon terminal from elementary OS on my Ubuntu 14.04 or newer LTS releases? If yes, how can I?


I have access to the full library of lynda.com in the university. I would like to know how I could download the videos so that I can watch them at home. As a tip: If I send the link of the video with the help of "Internet Download Manager" I can watch the same video without being in the network of the university! But it has to be done for each and every video. How can I do this for all the small and big videos on the page in one tutorial? Thank you in advance!

I am trying to download a Flash video, so I can try to convert it to a normal DVD.  (.)  Is it possible to download this video?  If so, how could I do this?


I'm on transition from Mac OS-X to Devuan. Trying to make the learning curve not as steep, I need to install some non-free software. Reading through forums, I understand there is a command that will allow me to install Dropbox, skype, bluetooth audio outputs, etc. etc.on my system. I know this is highly discouraged, but I need these apps so as to let go of my Mac completeley, and then slowly do the complete migration into free software.

I have a Dell PowerEdge T710 I'm trying to run as a home server. I have successfully installed Devuan, however I failed to set up the network properly. I'm wondering if there's any way to add the non-free network drivers for its Broadcom Limited NetXtreme II BCM5709 Gigabit Ethernet controller. I'm also open to reinstalling, but if I'm gonna do that I'd like some guidance on adding the proper network firmware to the installation image. I'm also open to giving up and using the debian non free net install iso. (I'm using Devuan to play with other init systems eventually but its not super important that I stay with this distribution)


From my understanding, for a common microcontroller (e.g. AVR, PIC), there are generally two methods of programming its flash memory.   Using a programmer:  (or some variant?) Some form of a bootloader, to which an external device communicates, ultimately allowing the microcontroller to flash its own memory.   Certainly there must be a very good reason to use a bootloader, else its current widespread use would be very odd. I just haven't seemed to have fully grasped it yet.  Is it that a programmer is expensive? But then, there are . Is the cost of one extra IC enough to warrant the use of a bootloader? If I'm not mistaken, the latest Arduinos get rid of the FTDI chip altogether, replacing it with an ATmega processor that does the USB to serial interfacing. Surely it would be possible to integrate the programmer's function on this IC for instance?  Or take for example, the PIC microcontroller. There is something I've seen called the . If something like this, with virtually no active components, can program a PIC then,   Why use a bootloader at all? What is the purpose of the relatively much more complex  (aside from robustness)? Debugging capability?

I've met many projects in which an AVR microcontroller uses with a bootloader (such as the Arduino), but I don't understand the concept very well.  How can I make a bootloader (for any microcontroller)?  After writing my bootloader, how it is programmed to the microcontroller (like any .hex program burnt on the flash rom of the AVR, or some other method)?


Suppose we uniformly and randomly select permutations from the 20!   Permutations of 1, 2, 3,..., 20.  What is the probability that 2   appears at an earlier position than any other even number in the   selected permutation?   A. 0.5  B. 0.1 C. 9! / 20! D. None   According to the work book the answer is (D)  However am getting the answer as 0.1  Here goes the explanation.   The first even number is 2.  Selection of these numbers is analogies to arranging them in 20 blanks.    Suppose 2 is filled in the first blank. then the remaining 19 elements can be arranged in 19! Ways.  Suppose 2 goes into the second blank. The 1st blank can be occupied by an odd number in 10P1 ways and the 2nd blank can be filled with 2 in 1 way while the remaining 18 blanks can be filled in 18! Ways  Hence (10P1)(1)(18!) ways Suppose 2 goes into the third blank. The 1st two blanks can be occupied by two odd number in 10P2 ways and the 3nd blank can be filled with 2 in 1 way while the remaining 18 blanks can be filled in 17! Ways  Hence (10P2)(1)(17!) ways   Generalizing the above three steps.      For i = 0 to 10      Summation of      (  10Pi )(1)(19 - i )!    Evaluating the above summation in the calc, I got 1/10 = 0.1  Let me know if I missed anything in the calculation.

Suppose we uniformly and randomly select a permutation from the 20! Permutations of 1,2,3,...,20. What is the probability that 2 appears at an earlier position than any other even number in the selected permutation?  My approach :   2 in first position ==> 1*19! (1 is the position of 2)  2 in second position ==> 10 *1 *18!  2 in third position ==> 10*9 *1 *17!  . . .  2 in 11th position ==> 10*9*8*7*6*5*4*3*2*1*1*9!  But this was asked as a multiple choice question in GATE 2007 and the options were  (A) 1/2   (B) 1/10  (C) 9!/20!  (D) None of these  I am not able to reduce this analysis to a given option.


Let $f(x,y)=     \begin{cases}       \frac{2x^2y}{x^2+y^2} & \text{if }  (x,y) \neq (0,0) \\       0       & \text{if }  (x,y)=(0,0) .  \end{cases}$  (i) Prove the directional derivatives of $f$ exist in any direction at the point $(0,0)$.  (ii)¿Is $f$ continuous on $(0,0)$?  For (i) I took $u=(u_{1},u_{2}) \in \mathbb{R^{2}}$ such $\|u\|=1$ and $0=(0,0)$. So $$\lim_{t \to 0} \frac{f(0+ t u)-f(0)}{t}=\lim_{t \to 0}\frac{2(tu_{1})^2 (tu_{2})}{(tu_{1})^4+(tu_{2})^2}=\lim_{t \to 0}\frac{(t^2 u_{1}^2)(t^2 u_{1}^{2}) tu_{2}}{t^{4}u_{1}^{4}+t^{2} u_{2}^{2}}$$. But I cannot find the limit when $t$ approaches to $0$. Which by finding them I would prove the directional derivative exist at every direction right?  For (ii) I got the intuition $f$ is not continuous at $(0,0)$ so I took $\lbrace (\frac{1}{k},\frac{1}{k}) \rbrace_{k \in \mathbb{N}}$ and $\lbrace (\frac{1}{k},0) \rbrace_{k \in \mathbb{N}}$ which are two different sequences in $\mathbb{R}^{2}$ converging to $(0,0)$. However, $\lbrace f(\frac{1}{k},\frac{1}{k}) \rbrace_{k \in \mathbb{N}}=\lbrace \frac{1}{k^{2}} \rbrace_{n \in \mathbb{N}} \to 0$ and $\lbrace f(\frac{1}{k},0) \rbrace_{k \in \mathbb{N}} \to 0$. So maybe my intuition was not right?  Also I've have approach $(0,0)$ through $(x,mx)$ and when this and gives me 0 as this value approaches to zero bit I cannot find another trajectory approaching through $(0,0)$ which gives me another value distinct to $0$. :(  Can anyone help me end the proof of continuity or not continuity, please?

Let $f(x,y)=     \begin{cases}       \frac{2x^2y}{x^2+y^2} & if & (x,y) \neq (0,0) \\       0       & if & (x,y)=(0,0) .  \end{cases}$  (i) Prove the directional derivatives of $f$ exist in any direction at the point $(0,0)$.  (ii)¿Is $f$ continuous on (0,0)?  For (i) I took $u=(u_{1},u_{2}) \in \mathbb{R^{2}}$ such $\|u\|=1$ and $0=(0,0)$. So $$\lim_{t \to 0} \frac{f(0+ t u)-f(0)}{t}=\lim_{t \to 0}\frac{2(tu_{1})^2 (tu_{2})}{(tu_{1})^4+(tu_{2})^2}=\lim_{t \to 0}\frac{(t^2 u_{1}^2)(t^2 u_{1}^{2}) tu_{2}}{t^{4}u_{1}^{4}+t^{2} u_{2}^{2}}.$$ But I cannot find the limit when $t$ aproaches to $0$. Which by finding them I would prove the directional derivative exist at every direction right?  For (ii) I got the intuition $f$ is not continuous at $(0,0)$ so I took $\lbrace (\frac{1}{k},\frac{1}{k}) \rbrace_{k \in \mathbb{N}}$ and $\lbrace (\frac{1}{k},0) \rbrace_{k \in \mathbb{N}}$ which are two different sequences in $\mathbb{R}^{2}$ converging to $(0,0)$. However, $\lbrace f(\frac{1}{k},\frac{1}{k}) \rbrace_{k \in \mathbb{N}}=\lbrace \frac{1}{k^{2}} \rbrace_{n \in \mathbb{N}} \to 0$ and $\lbrace f(\frac{1}{k},0) \rbrace_{k \in \mathbb{N}} \to 0$. So maybe my intuition was not right? Can anyone help me end the proof of continuity or not continuity , please?


So just to start off, I have checked that all the hardware I have is compatible with one another, and I have no problem running video games which use up my gpu and cpu in unison. However, when it comes to blender, even tho I set my device to GPU COMPUTE and i am on feature set: supported (ive tried experimental), whenever I render, I can see that my cpu sky rockets to 100% load! and zero gpu. I dont understand why this is happening. I have updated my drivers for my gpu and re-installed blender. I really dont know what to do! It keeps crashing after about 30 or so minutes but it isnt a continues crash. Sometimes, it renders completely...  Any help would be GREATLY appreciated! Yokubo~

I want to enable GPU rendering, but there is no option in User Preferences > System:    Why is this? How can I get cycles to render using my GPU?


I am working on a game and was going to create a jar file of it to send out a beta version to some of my friends so that I would know how the game looks on different resolutions and how it runs on worse and better computers. The problem is that when I run the jar file it will be completely black and nothing will happen.   I think that I have done the path for the images wrong because if i remove all the images from the net beans folder it will look exactly like when I start the jar. I have done the path for the pictures by just writing their name and having them in the same folder as the classes.   The jar file looks like this: Two folders, META-INF and Apocalypse. Inside META-INF is the manifest file, it looks like this:  Manifest-Version: 1.0 Ant-Version: Apache Ant 1.8.4 Created-By: 1.7.0_17-b02 (Oracle Corporation) Class-Path:  X-COMMENT: Main-Class will be added automatically by build Main-Class: Apocalypse.Main   Inside the Apocalypse file is all the classes and all of the images, to give an example of how I get the images in the code I get them like this ImageIcon ii = new ImageIcon("Image.png") I don't have any path to the image  but shouldn't this code work if I have the images in the same folder as the classes? How else would do the path to the images (if it is them that is the problem)?

When running a Java app from eclipse my ImageIcon shows up just fine.  But after creating a jar the path to the image obviously gets screwed up.  Is there a way to extract an image from the jar at runtime so I can then open it up?  Or, is there a better way to do this?  I'd like to distribute a single jar file if possible.


There seems to be substantial overlap in the respective question domains of Ask Different and Super User, as the latter contains thousands of Apple-specific questions. What are the rules, guidelines, or etiquette for determining which site is more appropriate for a given Apple-related question?  (I gather that cross-posting is not allowed.)

There seems to be more than a few computer science/programming Stack Exchange networks (is that the correct term?). Stack Overflow, being the first, has by far the most users, questions, and answers.  What is the reasoning for creating the others, and are there clear guidelines for which kinds of questions should be posted? I can see a large amount of potential overflow, many cases of people not getting a good answer to their question, because the person who has the answer isn't browsing that particular network at the moment.  I understand that they were probably created for organizational purposes, but wouldn't it almost make more sense to just have them as categories under Stack Overflow, keep them separated but still connected, instead of making people have to create multiple 'account's, one for each network?  I am sure there was a very good reason to break them up, but as someone that is new to SE, it can be somewhat intimidating to decide which one to post in to ensure you get a good answer. For example, if I am a computer science student, my first instinct might to be to post in the computer science network, until I see that it literally has 1% of the users as the Stack Overflow network, which still seems to be for programming/computer science related questions.  So my second instinct would then to be to post it into the Stack Overflow site on the basis that I have a significantly higher chance of my question being seen and getting a good answer. Then I notice that there is also a 'programmers' network, and I don't even begin to know where that fits in. I, and I am assuming most people, will probably just post on Stack Overflow to be safe.  My question is, other than the short little description blurb of each one, is there a clear cut set of guidelines which what each network is intended for, what kinds of questions should go to each one, and is anything being done to encourage people to post in these newer, smaller (more specialized?) networks as opposed to just posting in big daddy Stack Overflow?  Now again, this is for computer science/programming/"why isn't this code doing what I want?" related questions, I am not saying that if I had a question about Linux or WordPress or something I would have the same confusion.


I am using a  and am unable to eject the hard disc from my laptop .   I have tried to right click and eject but i get the following error message :    I have tried the following from  but it does it work also.   Is there any other way to eject my disc ???

The slot-loading optical drive in my Dell Studio Hybrid has been acting up. Sometimes it works fine, sometimes it churns and makes some unpleasant sounds. Now I can't even get it to eject the disc that's in there.  Many drives have an "emergency eject" pinhole, but I don't see one here. How can I get the disc out?


I have a Nexus 10 on which I have a master account, and a secondary  (restricted) account for my kids.  Recently, one of them got hold of it while it was logged in and installed a bunch of games. I removed them again — or so I thought. I just found out that, while they don't show up in the list of apps tray, they do show up among the app permissions for the secondary account, as well as in the list of apps available via settings -> apps.  I can't uninstall them from either location. While I suspect I can I uninstall them from the secondary account, how do I know they're really gone if I do so?  Shouldn't I be able to uninstall them from the master account?

I am having a problem with uninstalling apps on Android 5.0 (Nexus 5). I am developing an Android app, so I debug/run the app directly on my device. For production, I exported the same app with my keystore, uninstalled the debug APK that I ran earlier, tried to install the signed APK, and I got this error:      An existing package by the same name with a conflicting signature is already installed.   Is it because the bytecodes are still in the ART runtime? Anyone has any idea how to solve this?


I am new to Star Trek. Well, I have seen random episodes here and there, but I have never fully watched a series. I am curious as to where I should start in my new adventure as there are several different series/movies out there. If anyone could give me suggestions that would be wonderful!

I don't know anything about Star Trek except for the fact that it's about spaceships.  In  the person only wanted to watch the TV series. I want to watch every movie and TV series there is about Star Trek but I don't know where to start. I found this page on  which is about a time line. Do I need to watch it in this order? Are the movies and TV series related?


[TIFR-GS 2011, Part B, problem no. 1] Let $A$ be a $2×2$ matrix with complex entries. The no. of $2×2$ matrices A with complex entries satisfying the equation $A^3=A$ is infinite. They asked if the statement is true or false.   From the given equation, I've found that the eigenvalues of $A$ can be $0$, $1$, and $-1$. Now I took a trial matrix and tried to satisfy the equation, but it doesn't help in any way. Any help would be appreciated.

Let $A$ be a $2 × 2$-matrix with complex entries. The number of $2 × 2$-matrices $A$ with complex entries satisfying the equation $A^3 = A$ is infinite.  Is the above statement true? I know that $0$ and I are two solutions. But are there any more solutions?


It has always annoyed me that an Ampere is an SI unit, rather than a Coulomb. Why is this the case? Was current discovered first historically? I believe that the standards were published in the 1960s, couldn't we measure charge accurately by then?  To me at least, a Coulomb is more 'fundamental' than an Ampere.  What's more, (in SI units) charge being described as the amount of electricity carried over 1 second by 1 ampere of current does not seem very intuitive. I can't think of any other quantity that (in SI units) is a quantity over seconds, in most cases it is a quantity per seconds. If a Coulomb was an SI unit then an Ampere would be 'Coulombs/Charge that pass per second' which is more logical for me, and would seem more measurable experimentally (like the gold leaf or Coulomb's electrometer).   As I understand it, SI units were developed out of a necessity to standardise measurements internationally, are were chosen as such that each of the SI units were the 'base' measurements. Obviously if the aim was to standardise then it does not matter which units were chosen as long as consistency was achieved, but as 'base' units were chosen, why was charge not ahead of current?    If current was deemed more 'base' (forgive the poor phrasing), then why current over resistance, or voltage for that matter? It seems odd to define voltage or resistance in terms or current, rather than defining all three in terms of charge.   I also have a vague recollection of being told that current was chosen after it was deemed very implausible (through dimensional analysis) to express electrical quantities solely in terms of weight, time and distance ($kg,s,m$), is this true?

I always thought of current as the time derivative of charge, $\frac{dq}{dt}$. However, I found out recently that it is the ampere that is the base unit and not the coulomb. Why is this? It seems to me that charge can exist without current, but current cannot exist without charge. So the logical choice for a base unit would be the coulomb. Right?


I have a standalone Java program with the following command :  String p2 = System.getenv("USERPARAMETER");   How I can set this system variable in NetBeans 8.0 as if USERPARAMETER variable was coming from command line?

How do I set environment variables from Java?  I see that I can do this for subprocesses using . I have several subprocesses to start, though, so I'd rather modify the current process's environment and let the subprocesses inherit it.  There's a System.getenv(String) for getting a single environment variable. I can also get a Map of the complete set of environment variables with System.getenv(). But, calling put() on that Map throws an UnsupportedOperationException -- apparently they mean for the environment to be read only. And, there's no System.setenv().  So, is there any way to set environment variables in the currently running process?  If so, how?  If not, what's the rationale?  (Is it because this is Java and therefore I shouldn't be doing evil nonportable obsolete things like touching my environment?)  And if not, any good suggestions for managing the environment variable changes that I'm going to need to be feeding to several subprocesses?


I have to use the math.random to populate my array with 25 random integers between the range 10 and 99. I'm also having problems trying to print the array. Instead of the full array being printed, only the memory location is printed. How to I write the command for it to print? Thanks in advanced. This is how I've written my code and I know there's something wrong with it but just done know how to iron it out. Thank you in advance   public class Proj5COMP110 { public static void main(String args[])  { System.out.println ("Project 5: Quick Sort");     int i;     int mSample [] = new int[25];     for ( i= 0; i< mSample.length ; i++)      {         mSample[25] = (int)(Math.random ()* (99-10)+10);     } System.out.print(mSample[25]);  } }

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]


If I have triangle fan that makes a circle, for example what you get when you Add->Circle, with fill type Triangle Fan, and I want to add more edge loops radially, what's the best way to do that?  I can sort of do this if I extrude the outer edge, then scale down the 'old' outer edge. Once I do this I can do loop cut like normal between the two but this modifies the original edge. I'd like to figure out a way to do this that doesn't touch the outer edges.

Need a way to do a loopcut- ish thingy on the blue line


I am trying to make a cake stand. Here is what it looks like:  And here is it in wireframe:  The thing is, when I use a reflective material, I can see these lines running along the face of the cylinder and I can't seem to get rid of them (I've tried adding additional edge loops to no avail):   To be specific, I'm talking about the lines that kind of look like the old Japanese flag:  What are these and how do I get rid of them?

So, I just was trying to get back into blender, and I made .  Unfortunately, this cup has some issues right at the bottom of the inside, and I can't figure out why.  You can download the blend file .  And just for good measure, here is a screenshot of the problem.


Full statement: If $a, b, c > 0$ and $a+b+c = 6$, Find the minimum value of $(a+\frac{1}{b})^2 + (b+\frac{1}{c})^2 + (c+\frac{1}{a})^2$ I've found this problem online, to me it seems like a typical olympiad inequality problem. However, I wasn't not able to solve it, at least correctly. I tried using the AM-GM inequality directly, but I think I did a mistake in that approach or the approach itself is incorrect since I got the minimum to be 432, which is obviously false and easily proved so by a direct calculation.

If $x>0$, $y>0$, $z>0$ and $x+y+z=6$ then find the minimum value of    $$ f(x,y,z)=\left(x+\frac{1}{y}\right)^2+\left(y+\frac{1}{z}\right)^2+\left(z+\frac{1}{x}\right)^2. $$   Thanks in advance.


I haven't bought a house, but I have my own quarters as:      the Archmage of Winterhold, after Savos Aren dies and I bring back the Staff of Magnus.   If I put some items in a chest by the bed, will they stay there permanently until I remove them, or could they be stolen by NPCs, disappear over time, etc.?   On a related note, I've noticed that items remain until I come back when dropped arbitrarily across landscape, buildings, and caves. Has anyone experienced a case where this is not true?

I'd like to find a place to store stuff while I'm out adventuring, without spending 5000 on a house (at least, until I can afford that...). Where can I safely store items without worrying about them disappearing?   There are two possible places that come to mind,  (to which I have the key and was told I could stay), and the small bedroom given to me at the  (which I was told was mine, despite seeing J'zaro sitting in it later). Can I store items safely in either of these places?


– Schematic created using  There is also the resistance of the Mosfet which is equal to 0.25(Ohm) I just didn't know how to add it to the circuit. We're gonna call it Rdson. First question says: Calculate Ids that passes through the transistor. Vcc - rIds - Rdson x Ids = 0 Ids = 12/ (0.25 + 1.25) = 8 A Second question says: Calculate VDS(max) Vds = Ids(r + Rdson) = 8(1.5) = 12v That's what I don't understand. Why the book included r in calculating VDS? Isn't it supposed to be: Vds = Ids x r Did the book make a mistake here? Also, is VDS(max) the same as normal VDS? My problem: How VDS(max) is calculated in this circuit? Is the way the book solved it correct?


Today (August 2020) I opened the Start Menu in Windows 10 and typed the beginning of a program name, in order to launch the program. After a couple keystrokes a "Roblox" ad suddenly appeared beside the search results. What's strange is that in Settings -> Start, the option Show suggestions occasionally in Start is disabled. Also all the settings described in the answers to  have already been disabled. How come I'm seeing this ad then? Are there other anti-ad options that I need to set? The ad cannot be right-clicked.(Windows is reaching the ultimate bottom in professionality...). Edit: I should have taken a snip of the ad. Now it isn't appearing any longer. But here's the rough position where it appeared, in red:  Thank you.

My Windows 10 Home Edition computer frequently pops up various ads for Microsoft services. For example, just now it popped up a dialog that said "Make logging in even easier! Install Microsoft Authenticate" or something like that. How can I disable this sort of activity?


We have our every day plane $\mathbb{R}^2$ which we want to paint using two colors in such a way that no four points form a square of the same color. This means that for any square on the plane its vertices have different colors.  Is it possible to paint a plane in such a way?

Color every point in the real plane using the colors blue,yellow only. It can be shown that there exists a rectangle that has all vertices with the same color. Is it possible to show that there exists a square that has all vertices with the same color ? If it is not possible, please give me an example of a coloring of the real plane that does not have monochromatic squares.  To give the viewers an idea about other similar results (which they might find useful), for any coloring (2 colors) of the real plane:  1) There exists three collinear points having the same color, such that one of the points is the midpoint of the line segment that joins the other two.  2)For any two angles $\theta,\phi$ there exists a monochromatic triangle that has angles $\theta,\phi,180-(\theta+\phi)$  3)For any angle $\theta$, there exists a monochromatic parallelogram with angle $\theta$  Now its natural to ask if there are any monochromatic squares.  Thank you


When "to" is a preposition: I look forward to receiving your letter.  When "to" is part of the infinitive: I expect you to come over.  My question is, how could I know whether "to" is a preposition or part of an infinitive? Is there any rule behind?

I want to see you.   I look forward to seeing you.      How can one say "to" in the first sentence is an infinitive marker and in the second sentence a preposition when we are given just the following two sentences and are asked to fill in the blanks?        I want to ____(see/seeing) you.   I look forward to __(see/seeing) you.


I know the answer would be 'because Miggs threw semen at her'. Now did that made Lector feels sorry and offended for Clarice and he just wanted to help her or did he decide to tell her because he knew Clarice wouldn't come back to meet him again after such she was humiliated by miggs. Meaning, that he saw his chance of getting out of the cell was at risk. Why do you think Lector changed his mind really ?

In The Silence of the Lambs while Clarice first comes to visit Dr Lecter for his assistance, he drives Clarice away. But seems to change his mind when he sees Miggs (the next cell prisoner of Dr Lecter) throw his semen on her.   Did Dr Lecter decide to help Clarice only because this incident happened to Clarice? If nothing happened while Clarice retured, would Dr Lecter completely ignore her?


I am upgrading from Windows 7 to Windows 8.1. I have a lot of data stored in my PC, It would be very tedious to back up all of the data. I have stored the data in local disks other than the system files containing disk (local disk: C), so is there any way to uninstall Windows 7 and upgrade it to newer OS without deleting any of my personal data?

I want to upgrade from Windows 7 to Windows 8. How can I do this while keeping all of my files in-tact? Is it possible to retain all of my applications and user settings, too?


If I have an id:  #my~~id   Q#1: Is there a way to target it using js/jQuery? Ex:  var myid = $('#my' + ~~ +'id')   Update:  The 'duplicate' doesn't address my question about replace as this question isn't about spaces in a id.

Does anyone know how to select an item in the DOM by ID with jQuery, when that ID has a space?   For example, the ID of my item would be
Stuff
   How would I select this with jQuery?   If I just do   $("#content Module").whatever()    jQuery will try to find an item with both the ID of content and the ID of Module, which is not what I am looking for.  I should add that I am working with an old code base where these two word ids are used extensively, so going through and changing all the IDs would be bad.


I tried to uninstall kubuntu-desktop after I decided I didn't want it. I had a hard time doing this and eventually used the terminal to get rid of it. I used some code given to me by someone from this site and it didn't work for me. Instead I saw it start deleting apps from ubuntu-desktop and I so I stopped it. I lost the terminal and had to use xterminal to try to get it back. It's doing that in the background as I write this and I'm really lost. Before I tried to remove it Kubuntu was still on my system, it had replaced ubuntu's icons and grub screen and was causing all sorts of problems, this is why I felt the need to remove it so badly. it would seem I've lost a lot of personal files, and this sucks pretty bad. Is there anything I can do to get these files back? I want to keep my settings and files? I should have a backup from a couple of days before but I don't know how to access it. I don't know what to do, all my apps are gone and I'm worried my files are lost forever. All I wanted to do was use Kubuntu, but it seems I've created a mess out of it. Please help, I have windows installed as a dual boot so I can use that if need be, but I dislike using windows and want to just use Ubuntu.

I installed kubuntu-desktop just to experiment with its interface.  Then I decided to remove and did the traditional apt-get purge and autoremove but it seems elements of kubuntu are still there. For example interface elements, scrollbars, bootscreen etc are still there.  Is there any method I can completely remove without installing a fresh copy of ubuntu?


Apparently there are only 2 at any given time. A Sith and his apprentice. There are numerous Jedi Masters, thousands of Jedi Knights and apprentices and countless younglings. A veritable assembly line of Jedi. They even have a huge temple to hang out in. So why are Sith such a problem when they have to slink around in back alleys and dark corners? Is a Sith so much smarter and more powerful than all the Jedi combined?

If there are so many Jedi that there's even a Jedi Order, how hard would it be to hunt down two Sith lords? Once they found those two, wouldn't that be the end of the Sith?


I've tried dual booting and installing Ubuntu 20.04 with the recommended methods on the internet using the latest Rufus with GPT (my system is UEFI), disabling Secure Boot, Fast boot, using "nomodeset" in the Grub bootloader (I have a AMD processor HP ENVY), but it always stops at this error screen while booting.  This black screen appears while I boot Ubuntu from my USB drive, and it hangs it here, nothing afterwards. I could install Ubuntu in VirtualBox on my laptop, but it has been weeks I've been trying to install it from my 16GB USB stick, but I had no success.

Recently I bought a new laptop that came with Windows 10 installed but not activated. I use both Windows 10 and Ubuntu 18.04, so I tried making a dual boot with a USB flash drive. It was recognized by the BIOS, I tried Try Ubuntu without installing and Install Ubuntu. With both options the PC freezes, and I need to press the power button. It's shown very fast some errors that are listed below:  [ 0.064522] ACPI Error: Method parse/execution failed \_SB.PCID.RPOB.PXSX, AE_NOT_FOUND (20170831/parse-550)  [ 0.066316] ACPI Error: [_SB.PCID.RPOB.PXSX], Namespace lookup failure, AE_NOT_FOUND (20170831/download2-191)  [ 0.066325] ACPI Error: AE_NOT_FOUND, During name lookup/catalog (20170831/psobject-252)  [ 0.246232] ACPI Exception: AE_NOT_FOUND. Evaluating _PRS (20170831/pci_link-176)  [ 0.246248] ACPI Exception: AE_NOT_FOUND. Evaluating _PRS (20170831/pci_link-176)  [ 0.246260] ACPI Exception: AE_NOT_FOUND. Evaluating _PRS (20170831/pci_link-176)  [ 0.246272] ACPI Exception: AE_NOT_FOUND. Evaluating _PRS (20170831/pci_link-176)  [ 0.246285] ACPI Exception: AE_NOT_FOUND. Evaluating _PRS (20170831/pci_link-176)  [ 0.246297] ACPI Exception: AE_NOT_FOUND. Evaluating _PRS (20170831/pci_link-176)  [ 0.246310] ACPI Exception: AE_NOT_FOUND. Evaluating _PRS (20170831/pci_link-176)  [ 0.246322] ACPI Exception: AE_NOT_FOUND. Evaluating _PRS (20170831/pci_link-176)   I'm using NVIDIA GTX 1050 Ti graphics card and Intel i7-8750H processor.  I talked to the customer support and they just said that my laptop might not be compatible with Ubuntu. I also tried Ubuntu 16.04, but there were no changes.  EDIT: Thanks a lot for all the answers, but unfortunatelly I returned the PC to the store, neither the technical support found a solution for the problem, they just said: "Our PCs are just able to work with Windows, anyother OS might work but without our warranty".


I'm a very novice user of ubuntu, tried installing ubuntu on my dell 7559 15" laptop. Installed it successfully after some search, I had to press e and add the following line to grub bootloader nomodeset added that... installed it successfully after when I went to start the ubuntu   I repeated the added nomodest in bootloader again to run ubuntu 16.04 ran it to login screen image below.    once I logged in no desktop loaded, the following image     Any Idea?   Kindly help me, what should I do to get it working...

When I login, nothing happens.   I am presented with my desktop wallpaper.    No Dash, no Launcher, nothing.