hp officejet pro 8715 Ubuntu 20.10 computer software have tried eithernet and usb neither works. If I ever get my printer operating again I have learned my lession, don't update to new software!!!

Let's assume that one has some HP printer and/or scanner and checked its support status on the corresponding page of HPLIP site - .  So one have the following information: the device Model name, Min. HPLIP Version and Driver Plug-in need.   What should one install to make Ubuntu fully support the HP printer and/or scanner?


Suppose I have 20 accounts on SE platform.  I have different About me description on the them. I want to take the decision to change my username on all accounts, but keeping my current description on each site.  Currently this is possible only by opening all each profile, clicking edit, editing the username and clicking Save profile button.  If I click Save And Copy Profile To All Stack Exchange Accounts button the profile description will be overwritten on all sites. I don't want such a thing to happen.  So, how can I change only the username on all sites, keeping the current profile information intact?

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


I wrote this code to merge two Lists (NodoLista is a single element of the list), but I get the NullPointerExcpetion at line 34 of Main. Can you help me?  public static void main(String[] args) {     NodoLista a= new NodoLista(4,new NodoLista(5,new NodoLista(6,null)));     NodoLista b= new NodoLista(7,new NodoLista(8, new NodoLista(9,null)));     a=fusioneOrdinata(a,b);     while(a!=null){         System.out.println(a.info);         a=a.next;     } }  static NodoLista fusioneOrdinata(NodoLista x, NodoLista y){ NodoLista pp=null; NodoLista a=x; NodoLista b=y; while(b!=null){     while(a!=null || b.info>a.info){         pp=a;         a=a.next;     }     if(b.info<=a.info){         pp.next=b;         b.next=a;     }     b=b.next; } return a;}  public class NodoLista { int info; //OBJECT= Classe da cui derivano tutte le altre, contenitore di oggetti (non di tipi primitivi) NodoLista next; // RICORSIVA  NodoLista(int info, NodoLista next){     this.info=info;     this.next=next; }}

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


Let $ S = \{(x,y) \in \mathbb R^2 : x^2+y^2 < 1\}$ be the unit circle in $\mathbb R^2$. Let $(X_1, Y_1), (X_2, Y_2),$ be independent, both having uniform distribution over $S$. Let $D$ denote the Euclidean distance between $(X_1, Y_1)$ and $(X_2,Y_2)$. Show that $E(D^2) = 1$. Here I integrated $$\int_0^1 \int_0^1 \int_0^{\sqrt{1-Y_2^2}}\int_0^{\sqrt{1-X_1^2}} (X_1 - X_2)^2 + (Y_1 - Y_2)^2 dX_1 dY_1 dX_2 dY_2$$

On pg. 64 of David William's book Wrighing the Odds, there appears the following exercise:     Problem. Two points $A$ and $C$ are chosen independently at random in the unit disc $D$. Let $d$ denote the distance between them. Prove that $E(d^2)=1$, where $E$ denotes expectation.   We have the measure space $D$ with the Lebesgue measure $\mu$, so we can form the product space $D\times D$ with product measure $\lambda=\mu\times \mu$. For any real $r\geq 0$, we can consider the subset $S_r$ of $D\times D$ defined as $S_r=\{(a, b)\in D\times D: d(a, b)\leq r\}$. Then if $f$ denote the distribution function of the random variable $d^2$, we have $\lambda(S_r)=\int_0^r f dx$. This would give us $f$, and then one can calculate $E(d^2)$ by using the fact that $E(d^2)=\int_{\mathbf R}xf(x) dx$.  But the above approach is cumbersome. The author also seems to have something else in mind, for he has given as hint "use the pythagorean theorem to exploit symmetry".  Can somebody see a better approach? Thanks.


I have 3000 photos taken this year (2017) on a camera which had the date & time set incorrectly so all these photos are stamped with a 2015 date.  I would like to change the time stamp on all of these photos. I am going to upload them to Google Photos eventually.  I know I can do this very easily on Google Photos but the problem is that there are other existing photos on the account and my 3000 photos will mix in with them so when I would want to change their date, I would have to go and hand-select one by one. And AFAIK there is no way to tell the Google Photo uploader to sync the photos into an album.  I guess an option would be to create the album on Google Photos via web and upload directly into the album but the upload will take forever and I am pretty sure I'd lose control over it (network issues, PC issues, etc).  So I thought I would do the change before uploading them. Is there any windows tool (command line will do) to - basically set the start date of the batch and the tool would move all the time stamps accordingly?

I have two camera bodies, I was shooting while on vacation, when I downloaded the photos to lightroom, one body was set to the correct date/time, the other was off by 722 days, 4 hours, 32 minutes.  Is there a tool available that can help me fix the date/time so that they appear in sequence while browsing my lightroom library?  I'd like for them to be as close to the right time.     I was able to adjust created year, month, date, but it doesn't appear lightroom will allow me to adjust increments (only hour increments).  Many thanks if you can help me in this task!


I've just asked a  and got downvoted unlike the plethora of other . Where do I ask such questions?

Is it appropriate to ask questions about software licenses/licensing on ? Or is the appropriate place  ? Or is there no appropriate site currently and we should suggest such a site on ?


I am in high school and I need to solve lots of problems which involve spring-block systems, pendulums, damped oscillations and so on. I am learning Lagrangian mechanics and I am already quite proficient in solving these problems with Newtonian mechanics by resolving the forces and by energy conservation. I think that the force method is time consuming. I have heard several people say that Lagrangian mechanics can very easily give the equations of motion and I was hoping someone with first-hand experience could tell if I should solve these types of problems with Lagrangian mechanics.

What is Lagrangian mechanics, and what's the difference compared to Newtonian mechanics? I'm a mathematician/computer scientist, not a physicist, so I'm kind of looking for something like the explanation of the Lagrangian formulation of mechanics you'd give to someone who just finished a semester of college physics.  Things I'm hoping to have explained to me:   What's the overall difference in layman's terms? From what I've read so far, it sounds like Newtonian mechanics takes a more local "cause-and-effect"/"apply a force, get a reaction" view, while Lagrangian mechanics takes a more global "minimize this quantity" view. Or, to put it more axiomatically, Newtonian mechanics starts with Newton's three laws of motion, while Lagrangian mechanics starts with the Principle of Least Action. How do the approaches differ mathematically/when you're trying to solve a problem? Kind of similar to above, I'm guessing that Newtonian solutions start with drawing a bunch of force vectors, while Lagrangian solutions start with defining some function (calculating the Lagrangian...?) you want to minimize, but I really have no idea. What are the pros/cons of each approach? What questions are more naturally solved in each? For example, I believe Fermat's Principle of Least Time is something that's very naturally explained in Lagrangian mechanics ("minimize the time it takes to get between these two points"), but more difficult to explain in Newtonian mechanics since it requires knowing your endpoint.


I have this application to upload files to server via API, is a WinForm application in c#, this application starts a process  This process is an .exe file from another WinForm Application. I tried to get the process by id, by name even get all the process and I can't find the process started. The problem is I run the process to upload files, the form has one cancel button, this button should pause the process and ask the user if he wants to cancel the operation or not, if he clicks yes I have to call another piece of code but I can't find the process and I can't interrupt or pause. Any thoughts?

How do I suspend a whole process (like the Process Explorer does when I click Suspend) in C#.  I'm starting the Process with Process.Start, and on a certain event, I want to suspend the process to be able to do some investigation on a "snapshot" of it.


When I first started to study quantum mechanics, my physics text book told that particles have spin of either 1/2 or -1/2. Then I recently read an article saying that gravitons are expected to be massless and have a spin of 2. What does this mean ?

I often hear about subatomic particles having a property called "spin" but also that it doesn't actually relate to spinning about an axis like you would think. Which particles have spin? What does spin mean if not an actual spinning motion?


My middle name on my passport is missing one letter, so different from my ticket.  Will this be an issue? Doroty vs Dorothy

We are flying with Monarch, but I booked the ticket through a package holiday company and forgot to give my husband's middle name at the time of the booking (they did not ask for it). We will travel to Tunisia and will have to provide API (Advance Passanger Information) at the check-in desk and as the API requires the full name (first, middle and last name) I am worried that they will notice that my husband's middle name is missing from the flight reservation.    Is there a rule that flight tickets have to contain middle names as well? I checked Monarch's website and although the middle name is emphasised for the API, it is not specified for ticket bookings; moreover, if you book your ticket online, they only ask for first name and surname.  Do you think this could create a problem? Can he be denied from boarding? (I don't want to call the airline, as I've heard airlines love charging for extras such as a name change so I am not sure if I would be provided with accurate information.)


What is the sum of the following series?  $$\sum_{n=1}^{\infty}  n^{-n}$$  It definitely converges by ratio test.

I need help with this exercise.  I need to prove $$\int_{0}^{1}x^{-x}\ dx=\sum_{n=1}^{\infty}n^{-n}$$  I think I should use some convergence theorem, but I'm stuck.  Thanks a lot!


What is the difference between the following pair of sentences?     He formed a resolution not to speculate any more.      He formed a resolution to not speculate any more

Which is more appropriate in the following sentence?     "I asked him to not judge her according to (or: based on) her beauty"   vs     "I asked him not to judge her according to (or:based on) her beauty"   or maybe you wouldn't choose either of the above, but something else?


Three reviewers assessed my paper and all of them rejected it (weak reject), and to be honest I am not so mad about the rejection. One of the reviewers gave really good feedback and his arguments about rejecting it were correct.  But: The other two reviewers gave comments that were really wrong. For example one of them said that my paper was short, but my paper had exactly the maximum allowed number of pages. Also his English was terrible and he was saying that the paper was written in bad English. I am not a native English speaker but my supervisor is, and he corrected all of my mistakes before submitting the paper.  Also the third reviewer made some claims (referring to my citations) that were wrong (so he didn't even read the papers that "supported" his arguments). I took the time and reread all of the papers that he referred to and all of his claims are false.  Lastly all of the reviewers gave completely different reasons for rejecting the paper which also seemed really weird to me.  I was thinking to complain to the conference but my supervisor suggested we shouldn't because we would just waste our time.  So my question is shouldn't peer reviews were public and is there any good reason that they are not?

A question I have been wondering for a while is if there exists an actual proof that a blind reviewing process (i.e. where the reviewers are anonymous, and the reviews not published) is better than an open one (i.e. where the reviewers are not anonymous and/or the reviews are published along with the accepted papers).   Basically, whenever I question the fact that having a blind reviewing process does not guarantee any quality (which, somehow, usually coincides with receiving a poor review for a paper ...), I'm told that anonymity is crucial for the reviewing process. But is there any proof of that? I don't believe there exists any perfect system, but I'm just not sure why does the blind (or even double-blind) one is considered as the best (or the "least worst").


Good morning,   my update manager is not showing the update to 16.04, but if I use the terminal sudo do-release-upgrade -d I'm asked to upgrade. I'm using 14.04. Is it just a matter of time or do we have to update manually?  Thanks

I'm following the , but on launching the upgrade tool I get this response:  Checking for a new ubuntu release No new release found   Am I doing something wrong? Is there a workaround?


Prove that for a given prime $p$ and each $0 < r < p-1$, there exists a $q$ such that   $$rq \equiv 1 \bmod p$$  I've only taken one intro number theory course (years ago), and this just popped up in a computer science class (homework). I was assuming that this proof would be elementary since my current class in an algorithm cours, but after the few basic attempts I've tried it didn't look promising. Here's a couple approaches I thought of:    (reverse engineer)  To arrive at the conclusion we would need  $$rq - 1 = kp$$  for some $k$. A little manipulation:  $$qr - kp = 1$$  That looks familiar, but I can't see anything from it.    (sum on $r$)  $$\sum_{r=1}^{p-2} r = \frac{(p-2)(p-1)}{2} = p\frac{p - 3}{2} + 1 \equiv 1 \bmod p$$  which looks good but I don't know how to incorporate $r$ int0 the final equality.      (Wilson's Theorem—proved by Lagrange)    I vaguely recall this theorem, but I was looking at it in an old book and it wasn't easy to see how we arrived there. Anyways, $p$ is prime iff $$(p-1)! \equiv -1 \bmod p$$  Here the $r$ multiplier is built in to the factorial expression so I was thinking of adding $2$ to either side  $$(p-1)! + 2 \equiv 1 \bmod p$$  which is a dead end (pretty sure). But then I was thinking, maybe multiplying Wilson't Thm by $(p+1)$? Then getting  $$(p+1)(p-1)! = -(p+1) \bmod p$$  which I think results in  $$(p+1)(p-1)! = 1 \bmod p$$  of which $r$ is a multiple and $q$ is obvious. But I'm not sure if that's valid.

I think the following is true:  If $q$ is coprime to $a$ then $a\mid (nq-1)$ for some $n\in\mathbb Z$.  I have started to first reducing $n\in\mathbb Z$ to $n\in\{1,\ldots,a-1\}$ and then considering all the cases $q = ka + j$ for $j=1,2,3,\ldots,a-1$. I stopped at $j=3$ and found that this is kinda messy. Does anyone have an elegant proof for this (maybe using some results from number theory)?  [Note: question has been generalized from prime $q\nmid a$ to $\,q$ coprime to $a$]


For instance, I'm trying to check if the following substring Mr x ("CEO") is in Mr X ("CEO") went to Washington using re.search('Mr. X ("CEO")','Mr. X ("CEO") went to Washington')  Unfortunately, re.search returns none

I want to use input from a user as a regex pattern for a search over some text.  It works, but how I can handle cases where user puts characters that have meaning in regex? For example, the user wants to search for Word (s): regex engine will take the (s) as a group.  I want it to treat it like a string "(s)" .  I can run replace on user input and replace the ( with \( and the ) with \) but the problem is I will need to do replace for every possible regex symbol. Do you know some better way ?


I have a search suggestion box that appears when a user types in the search box. I want to close that box when the user clicks outside of the parent div. I tried this method below using .not() to omit the parents div but it did not omit it and still closes it when clicked on the parent div.  I have looked at solutions using event propagation but those have their own perils so I'd really like to use a simple function like .not() to accomplish this.  JS  // close search suggestions     $("body").not('#searchbox').mousedown(function() {         $('.search-suggestions').fadeOut();     });   HTML

     <form class="form-inline clearfix">
         <input type="text" class="form-control" id="search-input" placeholder="Search">
       <button type="submit" class="btn btn-default pull-right"></button>     </form>

Browse:

result in New Homes

result in Renovation

result in Interior Living

I have some HTML menus, which I show completely when a user clicks on the head of these menus. I would like to hide these elements when the user clicks outside the menus' area.  Is something like this possible with jQuery?  $("#menuscontainer").clickOutsideThisElement(function() {     // Hide the menus });


I want to set the lang attribute of the HTML tag in webforms so that in the case of English, the output will be   <html lang="en">  This is how I do it; in markup, I have this:  <html id="SomeID" runat="server">   And in the code behind, I have this:  SomeID.Attributes.Add("lang", "en"); // or SomeID.Attributes.Add("lang", "fr");   The problem is that the actual output is   <html id="SomeID" lang="en">   The ID of the tag is still present so I tried adding this:  SomeID.Attributes.Remove("id");   But the ID is still showing.  So how do I set the lang attribute in my code-behind file so that the HTML tag only has the lang attribute.

I am using ASP.NET webforms on the .NET 3.5 framework. How can I achieve a custom attribute in the HTML tag such as:  <HTML lang="en">   I want to achieve this in the code behind on a common inherited base page. The attribute value would dynamically set based on a session value everytime a page is loaded.  Late addition: I want to achieve this without any ASP page changes to script tags if possible


Let $I\subseteq B$ be an ideal, we define the ideal norm of $I$ as the ideal in $A$ generated by the elements $N_{E/K}(\alpha)$ where $\alpha \in I.$ We denote it by $N_{E/K}(I).$  If $\mathfrak{p}$ is a prime ideal of $A$, then $A_{\mathfrak{p}}$ is a DVR. I want to see that the norm is multiplicative.  I know I have to use some kind of theorem that reduces to local cases, but I don't know how to manage this.  Of course if $I,J$ are principal ideals, then $N_{E/K}(IJ)=N_{E/K}(I)N_{E/K}(J)$ because of the multiplicity of the "number" norm, but, why this is happening when there are no principal ideals?  Thanks and sorry for my english.

I had asked this question before and got a partial answer.  Let $A$ be a Dedekind domain with quotient field $K$, $L$ a finite separable extension of $K$ of degree $n$, and $B$ the integral closure of $A$ in $L$.  The ideal norm $N_{L/K}$ is usually defined multiplicatively by the formula $N_{L/K}(\mathfrak P) = P^f$, where $P = \mathfrak P \cap A$ and $f = f(\mathfrak P / P)$.    Another way to define it is as follows: for fractional ideals $M$ and $N$ of $B$, the localizations $M_P$ and $N_P$ are free $A_P$-modules, so there is a $K$-module automorphism $\psi$ of $L$ for which $\psi(M_P) = N_P$.  One then defines the module index $[M_P : N_P]_{A_P}$ to be $Det(\psi)A$.  More generally one defines the module index $[M : N]_A$ to be $$ \prod\limits_P P^{\nu_P [M_P : N_P]_{A_P}}$$ If $M$ is a fractional ideal of $B$, one can define the norm $N_{L/K}(M)$ to be $[B : M]_A$.  (see Cassels and Frohlich, first section of Algebraic Number Theory)  I have seen a proof using Smith Canonical Form that these definitions agree when $M$ is a prime ideal, but I have yet to see a simple general proof that the norm (defined in the latter way) is multiplicative.  The "long" way of doing this is to look at the completions of $K$ with respect to the $\nu_P$, and then look at the ways in which $\nu_P$ may be extended to $L$ (which correspond to the prime ideals lying over $P$).  The special case $A = \mathbb{Z}$ is more clear, because the module index $[B : M]_{\mathbb{Z}}$ is just the ideal generated by the cardinality of $B/M$.


VLC was working fine until I upgraded to 15.04. When I try to install via Software Centre, I get this error message:  The following packages have unmet dependencies:   vlc: Depends: vlc-nox (= 2.2.0-1) but 2.2.0+ppa2.4 is to be installed  Depends: libavcodec-extra-56 (>= 6:11.2) but 6:11.2-1 is to be installed  Depends: libavutil54 (>= 6:11~beta1) but 6:11.2-1 is to be installed  Depends: libc6 (>= 2.16) but 2.21-0ubuntu4 is to be installed  Depends: libegl1-x11 but it is a virtual package  Depends: libfreetype6 (>= 2.2.1) but 2.5.2-2ubuntu3 is to be installed  Depends: libgcc1 (>= 1:4.1.1) but 1:5.1~rc1-0ubuntu1 is to be installed  Depends: libgles1 but it is a virtual package  Depends: libgles2 but it is a virtual package  Depends: libqtcore4 (>= 4:4.8.0) but 4:4.8.6+git64-g5dc8b2b+dfsg-3~ubuntu6 is to be installed  Depends: libqtgui4 (>= 4:4.8.0) but 4:4.8.6+git64-g5dc8b2b+dfsg-3~ubuntu6 is to be installed  Depends: libstdc++6 (>= 4.9) but 4.9.2-10ubuntu13 is to be installed  Depends: zlib1g (>= 1:1.2.3.3) but 1:1.2.8.dfsg-2ubuntu1 is to be installed   And via Terminal:  Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help resolve the situation:  The following packages have unmet dependencies:  vlc : Depends: vlc-nox (= 2.2.0-1) but 2.2.0+ppa2.4 is to be installed        Recommends: vlc-plugin-notify (= 2.2.0-1) but it is not going to be installed        Recommends: vlc-plugin-samba (= 2.2.0-1) but it is not going to be installed E: Unable to correct problems, you have held broken packages.   When I do dpkg --get-selections | grep hold it appears that no packages are being held  When I do dpkg --get-selections | grep vlc it shows this:  libvlc5                     install libvlccore8                 install vlc-data                    install vlc-nox                     install   Also when I try to remove it via Terminal it says it is not installed and therefore cannot be removed. I have also tried the daily release videolan ppa with the same unfortunate results. How can I get my good old VLC back? Thanks for your help!

Occasionally, when I'm installing stuff, I get an error like the following:  Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  package1 : Depends: package2 (>= 1.8) but 1.7.5-1ubuntu1 is to be installed E: Unable to correct problems, you have held broken packages.   How can I resolve this?


I have a development setup of subdomains with apache/wamp, everything is working as I need with the "regular" setup and separately with the "xyz" setup, but I have to change the configuration and restart the server everytime I need a different setup.  Is there a way to have both setups working at the same time?  I'm looking for answer that allows me to access both setups at the same time without changing the urls or ports I use to access them.  this is my regular setup  <VirtualHost *:9090>     ServerName localhost.com     ServerAlias *.localhost.com     VirtualDocumentRoot u:\wamp\www\subdomains\%1     <directory "u:\wamp\www\subdomains\%1">         Options Indexes FollowSymLinks         AllowOverride all         Order Deny,Allow         Deny from all         Allow from all     </directory> </VirtualHost>   This is my secondary (xyz) setup  <VirtualHost *:9090>     ServerName localhost.com     ServerAlias *.xyz.localhost.com     VirtualDocumentRoot u:\wamp\www\subdomains\xyz     <directory "u:\wamp\www\subdomains\xyz">         Options Indexes FollowSymLinks         AllowOverride all         Order Deny,Allow         Deny from all         Allow from all     </directory> </VirtualHost>

This is a  about  the use of a *AMPP's stack.    I recently had a talk with some experienced people and they suggested to me not to use a WAMP stack, and instead install apache, mysql and php separately.  I don't understand why they have suggested this, though, so can anyone tell me?  Is there a particular disadvantage of WAMP, or a particular advantage to installing all of them separately?  Since a WAMP stack itself is composed of apache, mysql and php, then what's the difference between using the WAMP stack and installing them all separately?


I just built a new computer coming from windows and installed Ubuntu 20.04.01, and I cannot connect to the internet. I tried an ethernet cable that previously worked on windows but the network manager cant seem to find it. I have been looking for an answer for hours and I cant find it. I have tried: sudo touch /usr/lin/NetworkManager/conf.d/10-globally-managed-devices.conf then restart NetworkManager, but its the same result. When I go to settings then network, the only options are to set up a VPN, I do not see Wired or Wireless options. I have also updated /etc/network/interfaces so it looks like this auto lo iface lo inet loopback auto eth0 iface etho0 inet dhcp auto eth1 iface eth1 inet dhcp  For the command sudo lshw -C network this shows up *-network UNCLAIMED  description: Ethernet controller  product: RTL8125 2.5GbE controller  vendor: Realtek Semiconductor Co., Ltd.  physical id: 0  bus info: pci@0000:03:00.0  version: 04  width: 64 bits  clock: 33MHz  capabilities: pm msi pciexpress msix vpd cap_list  configuration: latency = 0  resources: ioport:3000(size=256) memory:b3300000-b330ffff memory:b3310000-b3313fff  I even bought a wifi adapter, but still, once I plug it in it doesn't seem like linux finds it and then uses it.  Any suggestions? Do i need to install drivers onto a usb then to my new computer? I just want to use the internet.

So I did a fresh install of Ubuntu 20.04 on a computer with the new RTL8125B Realtek network card and I cannot get the network to work. I was very suprised since this is supposed to be the new feature of the 5.4 kernel (I have 5.4.0-26-generic installed). Does anyone have any idea on how to get it working? Thank you. $ lspci -knn | grep Eth -A3 06:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8125 2.5GbE Controller [10ec:8125] (rev 04) Subsystem: ASUSTeK Computer Inc. RTL8125 2.5GbE Controller [1043:87d7] Kernel modules: r8169 07:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon RX 470/480/570/570X/580/580X/590] [1002:67df] (rev e7)  $ dmesg | grep -i r8169 [    0.911236] r8169 0000:06:00.0: unknown chip XID 641


I am having trouble deciding on how to proceed with this problem:  Find an expression for $\Sigma_{d\mid n} d^2$ in terms of the prime decomposition $n=p_{1}^{\alpha_1}*p_{2}^{\alpha_2}*...*p_{t}^{\alpha_t}$ of n

The question is:  Develop a formula for $\delta_2(n)$, the sum of the squares of the positive divisors of $n$.


I'm not familiar with role-playing games so apologies if this question is poorly worded.   As an example of what I'm thinking of, suppose the player characters are on a ship, which capsizes. While escaping from the shipwreck they find an NPC clinging to flotsam. The players decide they cannot save the NPC, so they leave the NPC to drown. Unfortunately for them, the NPC had a quest-critical item (e.g., an artefact required to slay the BigBadBoss later). Since the item is now permanently lost, the quest will never succeed and the BigBadBoss is going to kill all the player characters. They're dead, they just don't know it yet.  How can a GM continue to progress the campaign if the player characters lose a plot-necessary item like this?  For this particular situation, I imagine the GM could attempt to give the quest-critical item to another NPC, but that might not be feasible (e.g. a player might have tried to examine the drowning NPC, and the GM described the NPC as possessing the artefact). It could also be something more severe as well, e.g. the players could kill a quest-critical NPC, and bringing the NPC back to life would be beyond belief.  I imagine the GM could also do nothing and let the players die, but then it seems like a rather dull game for the GM, since (s)he already knows the end result.  How can a GM continue to progress the campaign if the player characters cause a plot-critical item or NPC to be lost/killed?

As with most of my questions, this is more of a general "how to handle a special situation" and not a plea to solve an existing problem.  What is the best way to handle story deadlocks (as in: The story can't progress as originally planned and possibly even not at all)?  For example:   The PCs have killed a crucial NPC, or gotten him killed or "unavailable" through other means (Starting a battle, betraying him to the city guard if he's a criminal, ...) The PCs have made enemies with a faction they need to continue the (original) story ...   Aside from the obvious advice "don't let it come to that", "plan ahead for those situations" and so on, what can I do if I am surprised by an unexpected action of a PC that makes the original arc unviable?  The things I thought about are all pretty boring:   Divine intervention. The worst thing you can do as a DM, in my opinion, unless there is absolutely no other way. Adding a new NPC to replace the old one and going on as planned. Will create nasty plot holes (How did that guy find out about what you are doing, why was he never mentioned before, ...). Depending on the situation, this might be viable, but sometimes it makes too big of a plot hole (For example if you accidentally betrayed the local crime lord, who was the only one who had the exact plans you needed). Rollback. Pretty much equals divine intervention, with the added bonus that the PCs now know that the NPC is important, which might give away important plot twists. Depending on how good the players are at seperating player knowledge from character knowledge, this may sometimes be the best solution, but I'm still not satisfied, it feels like cheating to me. Improvising and discarding the original story. Makes for some great adventures, as I know first hand, but can be frustrating if you had an entire campaign planned that has become obsolete in its current form.   I have only been DM for two or three times yet, so I don't feel ready to improvise an entire adventure, like our old GM used to.  So, the question is: what have I missed? What other ways are there to rescue the story without (obvious) cheating?


I want to calculate areas of different polygons in QGIS in tabular format.

Using QGIS, if I load a polygon layer and make a new column, how do I fill that column with the:   area of each polygon and another column with length of the perimeter of each polygon?


A club consisting of 6 men and 9 women will choose a committee of 4. In how many ways can the committee be chosen if it must contain at least 1 man?  I started out this problem like this:  men   C(6,1)        =6  women   C(9,3)          =84   But then I realized that it was exactly the same as my problem before this one. The one before said it must contain exactly 1 man which I double checked my answer on here and it was correct. Now this question is asking for it to contain at least 1 man, so now I'm confused on how to solve it.

A club consisting of 6 men and 9 women will choose a committee of 4. In how many ways can the committee be chosen?  I'm not sure if this would be combination or permutation. If someone could help me out that would be great!


I note the discussion of the lack of female equivalent for uxorious.  Is there any equivalent for avuncular?

My brief researches only bring up the word "auntlike" to render the feminine equivalent of avuncular. Surely, though, and given the etymology of "aunt" [ < Latin amita -father's sister, old feminine past participle of amāre to love, i.e., beloved ], there must be a more lyrical word to hand.


I am trying to use Line breaks (\n) in return statement. But it doesn't work. \n gets printed in the return statement. I am not using any VF Page. I am trying this in my webservice class.  Below is the method structure.  global static string createNewCase() {     //...     return 'FIELDS :' + '' + response.fields + '/\n' +         'MESSAGE :' + '' + response.message +         'STATUS CODE :' + '' + response.statuscode; }   I tried by adding '/\n' this also did not work. Please help in how to do this. I tried to search for this. But all I get is the example of VF page and controller where escape=False is specified in controller.  I have tried the code mentioned in the  link for reference and made changes. Still it is not working.

My controller code is as follows -          for(String resStr : responseArray){             if(resStr.indexOf('r_error_str') != -1){                 responseString += resStr.substring(resStr.indexOf('=') + 1);                  responseString += '\n';             }         }   but when i display this 'responseString ' String using 'apex:outputLabel or apex:outputText or as Exception message '\n' is not converting in new line. Whole String is coming in one line.  Can anyone explain why is this happining


I will be flying on All Nippon Airways (ANA) out of Houston IAH soon, but ANA does not participate in the Trusted Traveler program so I have no way to provide the KTN that I received through Global Entry. Is there any way that I can access the Pre-Check lane in IAH using my Global Entry card (my ticket will not say Pre-check) or am I out of luck?  Edit: I believe this question is distinct from 'can I use pre-check on non-pre airlines. There is no way to prove that you have pre-check, but I have a physical Global Entry card which I can use as legal identification to board an airplane, so in my mind it is more objective proof of my pre-cleared status.

Can I use our Known Traveler Number for TSA PreCheck if the airline we are flying doesn't recognize them in their system?


How do I find the tangent line of the following hyperbola, given that the tangent line has to go through the point $(0, 0.08)$? $$x=\sqrt{19.8y^2-6.9y+0.7}$$ I know that there are two tangent lines that go through the point since this hyperbola is in the first quadrant and opens to the right, I need the tangent with the positive slope.

I have a hyperbola in the first quadrant opening to the right given with the equation $$x=\sqrt{19.8y^2-6.9y+0.7}$$ and I have to find the tangent line from the point $(0, 0.08)$ to the hyperbola (the tangent line with positive slope, so above the hyperbola if it's opening to the right).     The problem is I don't know what the tangent point is on the hyperbola because then I would just be able to find the slope and use $y=mx+b$ to find the equation of the tangent line.  My idea is since there are many lines that intersect the hyperbola from that point I have to maximize the slope between the point and the hyperbola and then I should be able to find the tangent line between $(0, 0.08)$ and the hyperbola. But I don't know how to find the maximum slope between the line that goes through the point and the hyperbola?


How can I find out on which partition my home dir is?

I have a lot of filesystems:   / on a PCI-E SSD swap on a SATA SSD /media/ned is a RAID5 array /tmp lives on RAM Parts of /home/oli are symlinked and bind-mounted in from ned I also have /media/jeff/ which is RAID1 that I store backups and bind-mount ~/.wine in off.   It's actually a lot more complicated than that. There are all sorts of extra symlinks that I need to untangle in the long run but for now I just need a nice way of taking a path and finding out where it physically lives.


As a Mongolian citizen planning to travel on a cruise, do I need a visa to each country or island where the cruiseship stops? If I already have a visa to the UK, will that be accepted in any country/island that does not require a visa of a UK citizen?

I am a Mongolian citizen currently in England on a one year visa.  Can I travel to British Virgin Islands, or other Caribbean islands that require a British visa using the visa I have for the UK, or do I need a separate visa for each country or island I visit?


As the temperature increases, the resistivity of conductor also increases why?

We know that in high temperature, resistivity in metals goes linearly with temperature. As temperature is lowered, resistivity goes first as $T^5$ due to "electron-phonon" interaction, and then goes as $T^2$ as temperature is further lowered due to "electron-electron" interactions.   My question is, is there an intuitive way of understanding the above power-law dependence at each temperature range physically?


In my code second scanf doesn't work and couldn't read the character. How can I solve that ?  #include <stdio.h> int main() { int a, result; // ***************** Menu ******************* printf("Hello !!! \n The Operations That This Calculator Can Do :"); printf("\n1. Simple Operations"); printf("\n2. Calculate The Biggest Number"); printf("\n3. Taylor expansion"); printf("\n4. Sum Digits Of a Number"); printf("\n5. Found The Prime Numbers Before The Number That You Entered"); printf("\nEnter The Number Of Operation That You Want : "); scanf_s("%d", &a); if (a == 1){     char ch;     int num1, num2;     printf("\n Please Enter Your Operation Like That (- 5 3 ) : ");     scanf_s("%c", &ch);     if (ch == '-'){ scanf_s("%d", &num1); scanf_s("%d", &num2); result = num1 - num2; printf("\n > %d", result); }     if (ch == '+'){ scanf_s("%d", &num1); scanf_s("%d", &num2); result = num1 + num2; printf("\n > %d", result); }  }  return 0; }

I've been having a lot of problems trying to figure out how to use scanf().  It seems to work fine with integers, being fairly straight forward scanf("%d", &i).  Where I am running into issues is using scanf() in loops trying to read input.  For example:  do {   printf("counter: %d: ", counter);   scanf("%c %c%d", &command, &prefix, &input); } while (command != 'q');    When I enter in a validly structured input like c P101, it seems to loop again before prompting me.  This seems to happen even with a single:  scanf("%c", &c)    in a while loop.  It'll do the loop twice before prompting me again.  What is making it loop twice, and how do I stop it? When I enter in less amount of input that programmatically wouldn't have another character or number such as q, pressing enter seems to prompt me to enter more.  How do I get scanf() to process both single and double character entries?


This is my file, which I saved as eclipse-start.sh    I also made it executable. But it always starts in gedit??

How can I make a bash script executable by double clicking just like .exe files in Windows? I tried , but there are two consequences:   the terminal twinkles, disappears, and nothing is done. you must specify to run in terminal in order to work.   I have a script that installs tomcat on an offline PC, including all dependencies of tomcat in the script. I need to make the script work on double clicking like windows since most who use the script will not be familiar with Ubuntu.  Forget the above explanation. I want to make a script that can be run by double-clicking on it, without using the terminal. Anybody knows how?


I am working with QGIS and ArcGIS Desktop 10.7.1 simultaneously.   Is there any way to transfer my symbologies and styles from QGIS to ArcGIS Desktop?   I could not find a way to do it so far.

We have a QGIS project that has symbols for a lot of different lines. Data comes from a geodatabase that is accessible to both QGIS and ArcGIS.  We now want to use the symbology of the QGIS project to style the features in the ArcGIS map document.  My first approach was to use SLDs. The QGIS style can be exported to SLD easily, but how can you style your features according to a SLD using ArcGIS Desktop?  Setting up a simple WMS does not suffice, both QGIS and ArcGIS Desktop need editing capabilities on the features.  If one could provide a SLD with a WFS (in a Esri-readable way) that would also be a possibility. Have found nothing for that, either.


The sort method Collections.sort(list) works on the list even though I pass by reference. However, when I use the following method, the list does not get sorted.  public void getSortedList(ArrayList<String> currList) {     ArrayList<String> list = new ArrayList<>();      Cursor cursor = database.rawQuery(             "SELECT * FROM " + TABLE_NAME + " ORDER BY name DESC", null);      while (cursor.moveToNext()) {         String name = cursor.getString(0);         if (currList.contains(name)) {             list.add(name);         }     }     cursor.close();      currList = list; }

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


I am flying Norwegian Air from Orlando, FL, to Singapore via Gatwick.  There is a change of plane on Norwegian but the bag is checked through. I'm not leaving the airport. Do I need a transit visa? Filipino passport holder leaving work and I have a Schengen visa.

Is there a website or some other way to find out if I need a transit visa for a short stop in the UK on my way somewhere else? Ideally this should give me the answer for all nationalities, and take into account any other visas I may have.


I've been looking for a way to sum the total areas of each polygon in specific classes using ModelBuilder. Many have suggested the "Summarise Statistics" option which creates a new table, is there any way of doing this by "Calculate Field" in a Total_ha field I've created especially in the original table for this? I have several hundred shape files to do, it would be a pain to have to join them with the Summary table...

I am doing hydrology analysis in ArcMap 10.2 and have a drainage area feature class containing hundreds of records.  Each record is assigned a drainage area name and acreage amount.   How do I sum all the acreage amounts for each drainage area name using a python script preferably in the field calculator?


I have selected a Pantone color from a Pantone book, let's say 285 C, now I want to make my artwork to that Pantone color and ready for print. How do I go about it?

Can someone please tell me the steps to input a Pantone number in Illustrator?    For example, I have selected what I want to color, now I want to make that selection Pantone #300.  Where do I input that "#300" so that my selection now using that color?    I've looked all over the swatch panel and do not see how or where to do that.


If $f(x)$ is a real valued continuous and differentiable function in $[0, 1]$ and $\int_{1/3}^{2/3}f(x)dx = 0$ minimize $\frac{\int_{0}^{1}f'(x)^2 dx}{(\int_{0}^{1}f(x)dx)^2}$

Let $f$ be a continuously differentiable real valued function on $[0,1]$.  It is given that $\displaystyle \int_{\frac{1}{3}}^{\frac{2}{3}}f(x) dx=0$     Find the minimum value of $\dfrac{\int_{0}^{1} (f'(x))^2 dx}{\left( \int_{0}^{1} f(x) dx \right)^2}$   I tried to use Cauchy-Schwarz to show that  $$\frac{\int_{0}^{1} (f'(x))^2 dx}{\left( \int_0^1 f(x) dx \right)^2} \ge \frac{\left( \int_0^1 \bigl| f(x)f'(x) \bigr| dx \right)^2}{ \left( \int_0^1 f(x) dx \right)^2} \ge \frac{ f(1)^2 - f(0)^2}{2 \left( \int_0^1 f^2 (x) dx \right)^2}$$ But I can't proceed from here.  Also, I don't know how to use the condition  $\int_{1/3}^{2/3}f(x) dx=0$


When I createa a solid, this is the way that it appears on the screen. Actually faces are planes but this is what I see, the edge seems to be jagged from far and as soon as I zoom in it becomes perfectly sharp. It never happened to me before. I use 2.9 in solid mode. Maybe I have done something wrong?

I have recently started using blender and one of the models I'm working on has dark shadows along edges. I started this model from scratch. I can't remember them being there when I first started the model, but I had trouble joining areas together and think I've pressed something I shouldn't have. However, there are so many options I'm not sure what I did.  Here is an image of what I mean   The one on the left has the shadow. As a test I started a new model, which is on the right in the image, and as you can see it doesn't have any shadows.  Also, occluded vertices partially show through the model. Occlusion doesn't work properly.   In orthogonal view small darkened triangles appear along the the edges.    I don't really want to start the model again from scratch so any ideas on how to remove this shadow would be great. Thanks.


(main method calling classes)  import java.io.*;  public class bob { public static void main(String[] args){     new bert();   new larry();       (creates a file and copys string to it)  public class larry{   bert bertObj = new bert();   public larry(){       try{       File file = new File("text.txt");        if(!file.exists())           file.createNewFile();       PrintWriter pw = new PrintWriter(file);       for(String x: bertObj.string){       pw.println(x);       }       pw.close();   }catch(IOException e){       e.printStackTrace();   }   } }       (reads a file and copies it into a string array)       (i havent initialised the string, i think that maybe the error, though i dont know how many values i will be storing inside it so i do not wish to do            String string[] = new String[100] for example.... what else can i do?)  public class bert {   String string[];   public bert(){       BufferedReader br = null;       try{           br = new BufferedReader(new FileReader("C:\\Program Files\\Java\\jdk1.8.0_101\\THIRDPARTYLICENSEREADME.txt"));           int counter = 0;           while((string[counter] = br.readLine()) != null)           {               counter++;           }           for(int x = counter; x < 4000; x++)               string[x] = "";       }catch(IOException e){           e.printStackTrace();       }finally{           try {               br.close();           } catch (IOException e) {               e.printStackTrace();           }       }   } }

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


I want to compare the means of non-random samples to population mean. However, most standard tests (eg. t-tests, ANOVA, Welch test etc.) are based on the assumption that samples are randomly obtained from the population.  In that case, is there any way to analyse the significant difference between the means of non-random samples?  Thanks.

Many clinical studies are based on non-random samples. However, most standard tests (e.g. t-tests, ANOVA, linear regression, logistic regression) are based on the assumption that samples contain "random numbers". Are results valid if these non-random samples were analyzed by standard tests? Thank you.


I have the following code:   from math import *   def weights(p1,p2,p3):     n =len(p1)     rows, cols = (n, n)     w = [[0]*cols]*rows      for i in range(n):         for j in range(n):             if i != j:                 w[i][j] += p1[i] * p1[j]      for i in range(n):         for j in range(n):             if i != j:                 w[i][j] += p2[i] * p2[j]      for i in range(n):         for j in range(n):             if i != j:                 w[i][j] += p3[i] * p3[j]      print("old")     print(w)      new = [[0]*cols]*rows       for i in range(n):       for j in range(n):         w[i][j] = w[i][j] + 1     print("new")     return w    six=[1,1,-1,1,1,1,1,-1,1,1,-1] three=[1,-1,1,1,-1,1,1,1,1,-1,-1] one=[-1,-1,1,-1,-1,1,-1,1,-1,-1,-1]  w= weights(three,six,one) print(w)   As evident from the console, the old value for w is some matrix of ints  I update every element by 1.   However, the code increases the value of each element by 10.  Is this a bug in python, or am I doing it incorrectly?

I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?


I have two paths in my drawing. I'm trying to sort out how to join them so that I can fill the inner parf of the F. Thoughts?

Say I have the following picture that I drew with a black brush then used Live Paint to color it.   How do I get rid of the black stroke?


I want to put Ubuntu, but I do not have USB-stick. Tell me, is it possible to install Ubuntu with SD-card?

Is it possible to download Ubuntu 12.04 to an SD card and then use that to install or to boot directly from it, rather than using a USB stick?  The plan is to install Ubuntu on an old Toshiba Portege M200 laptop, which does not have a CD drive.


I want to show the equivalence of two definition of positivity. Let $A \in \mathcal{L}(H)$, where $\mathcal{H}$ is the $n-$dimensional Hilbert Space $\mathbb{C}^n$. $A$ is positive if $\langle x,Ax \rangle \geq 0 $ for all $x \in \mathcal{H}$.     Show that $A$ is positive if and only if it is Hermitian ($A=A^*$) and all its eigenvalues are positive.   It is a classical exercise to show that . The difference in this question is that one only assumes the operator is positive and has to deduce that it is Hermitian and its eigenvalues are positive, which cannot be solved using the same approach.

Is there a simple way to show that a positive definite matrix must be Hermitian?  I feel there is a long drawn out proof of this to be had by taking unit vectors and applying the positive definiteness property, and brute forcing it.  But is there some simple clever proof why a positive definite matrix is necessarily Hermitian?


I wish to indicate clearly when a block starts and ends with "enclosing lines" in addition to the indentation.  I understand that I can do it with algorithm2e like so  \begin{algorithm}[H]  \SetLine % For v3.9  %\SetAlgoLined % For previous releases [?]  \KwData{this text}  \KwResult{how to write algorithm with \LaTeX2e }  initialization\;  \While{not at end of this document}{   read current\;   \eIf{understand}{    go to next section\;    current section becomes this one\;    }{    go back to the beginning of current section\;   }  }  \caption{How to write algorithms} \end{algorithm}   rendering as   However now, I am using algorithmicx. How may I achieve the same effect?

I am using the algorithmic package to typeset an algorithm. I would like to have connecting lines between the beginning and end of a loop or conditional like in the algorithm2e package. Is there an easy way to accomplish this, or am I better off switching to algorithm2e?


I want to find the remainder of 23.153 when divided by 23 i.e. 23.153%23. The remainder should come 0.153 but its coming as 0.1529999999999987.

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


I am Nigerian and my home is in Nigeria. I am living in India on a working Visa, which is about to expire.   My question is can I get a visa to visit the United States from India or do I need to go back to Nigeria and obtain a visa to the US from there?

I'm currently residing in a country other than my own, and am planning a business trip to the USA for a week. Being a Bulgarian citizen, I do not qualify for the ESTA visa waiver program, unlike other EU countries.  The US embassy in Sofia lists a  which they inexplicably describe as "really quite easy". Unfortunately, some of the steps involved would be a major inconvenience for me, as I'm not residing in the country currently, particularly the interview and the visa/passport delivery.  I was hoping it could be possible to apply for a visa from the country of current residence rather than my own, but I wasn't able to find any information on the US embassy's webpages concerning this.


I got this error in using pdflatex:  ! Undefined control sequence. l.6 \(1.5 \lt               x \lt 5.5\) ?  ! Undefined control sequence. l.6 \(1.5 \lt x \lt                     5.5\) ?    The tex-file is:  \documentclass[preview,border=2pt]{standalone} \usepackage{amsmath} \usepackage{tikz}  \begin{document} \(1.5 \lt x \lt 5.5\) \end{document}   The sequence "\lt" should represent "<" symbol. But it causes the error. Should I add some additional packages?

\documentclass{article} %\usepackage{amsmath} It does Not work ! \begin{document} \[ x\lt y \gt z \] \end{document}  What library do I have to use such that the document can render \lt and \gt as less than and greater than signs, respectively? Edit I am using MathJax library in my site under Asp.net Mvc 3. Web application is vulnerable to XSS and XSRF attacks so < and > should be avoided as the input from the users. My database will save LaTeX commands that can be rendered by both LaTeX compiler and MathJax. Therefore, I need \gt and \lt that already work in MathJax. Source:  Rendered:


Do I need a transit visa as an Indian passport holder for Germany in order to travel to Finland from Dubai?  Dubai - Germany (2hrs stop) - Finland   Provided I will have a Schengen Visa (Finland)?

I found many related questions on this site but I am still not sure about the rules. How can I decide if I need a visa to transit? Schengen members as of May 2021 are as follows:  Austria Belgium Czech Republic Denmark (excluding Greenland and the Faroe Islands - but an open border with the Schengen Area is maintained) Estonia Finland France (excluding overseas departments and collectivities) Germany Greece Hungary Iceland Italy Latvia Liechtenstein Lithuania Luxembourg Malta Netherlands (excluding Aruba, Curaçao, Sint Maarten and the Caribbean Netherlands) Norway (excluding Svalbard) Poland Portugal Slovakia Slovenia Spain (except Ceuta and Melilla) Sweden Switzerland


Assume our website domain to be www.example.com.   And we have created a separate testing environment within our main domain: Say : www.project.example.com.  So we have two versions within our main domain server. One is for testing and building new updates and the other one is live server.    I see www.projects.example.com indexed in Google which is our testing server.  Is there any option to restrict this testing environment from being indexed in Google?   thanks

I have some web pages that Google has indexed. I have now added a robots.txt file to exclude them, but should I also add a noindex tag? If so, then how do I do so?


I have the dawnguard DLC for Skyrim and I want to know what will happen if I become a vampire lord before I start doing the companions quests that eventually turns me into a werewolf.   If I complete dawnguard and chose to be a vampire lord before doing companions werewolf transformation, will I be forced to do the werewolf blessing or can I just skip it?   Also, if I do become a vampire lord, and choose to become a werewolf, will I be able to cure the werewolf disease and become a vampire lord again?

I'm not sure whether I want to become a vampire or a werewolf, or just remain a normal human being.  I'd like a chance to explore all my options.  I know there are ways to cure vampirism and lycanthropy.  And I'm pretty sure there's ways, at least with vampirism, to re-acquire the conditions.  What I want to know is if there is ever a point of no return?  Is there a point past which you become immune to either or both of these, or a point past which one or both can no longer be cured?  How many times can I change my mind before reaching one of these points?


I have an old sempron 1.60GHz single cored pc with 1Gb of ram and I want to know what version of Ubuntu should install into it(ubuntu 12.04,12.10,13.04 does not work)

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


Conventionally, people will say a probability of zero is equivalent as saying that the event is impossible.  But when we look at the probability from a mathematics perspective, probability is defined as the frequency of occurrence over the how many times the experiment is performed, limit as the number of trials goes to infinity.   Doesn't this mean a probability of zero is an occurrence that is arbitrarily small but possible? What are some of the ways to make this line of argument more rigorous?

I read a comment under :     There are plenty of events that can occur that have zero probability.   This reminds me that I have seen similar saying before elsewhere, and have never been able to make sense out of it. So I was wondering    if zero probability and impossibility mean the same? if an event with zero probability doesn't mean that the event is impossible to occur, how probability theory represents/describes impossibility?   Thanks and regards!


I want to screencast my minecraft gaming.  I did this firstly with recordmydesktop (and gtk-recordmydesktop). It works fine, but the file size is too high (564MB for about 5 min).  I also tested Kazam and switched the Codec to H264, AVI and WEBM. The file size is even larger.  Any suggestions for programs or other solutions?

How can I record my screen on Ubuntu?   The app I'm looking for has ideally all of these features:   Can record in a format that can be played back easily on any platform and/or accepted by YouTube or another popular video site Can record just a window (instead of the whole screen), possibly selecting it with a mouse click Can start recording after a configurable delay (e.g., I launch the app and have time to do arrangements to my desktop/window before actual recording starts)


So I have a column say A that looks like this:  I 15 0 3 15 M 8 0 8 21 Q 0 5 0 0   I can find the largest value with =MAX(A1:A100) I can find the smallest value with =SMALL(A1:A100,1)  How do i find the one before the largest and the one before that. I can use Large to call the Nth value, but then how do I know how many N values the function counts so I can know what positions it uses refer to the last 3 (largest and the 2 before)?  Ignoring duplicates - in the example the largest is 21, the one before is 15 and before that is 8. If I do =LARGE(A1:A100,3) it will return 15 as there is two of em in the column. And I'm looking for the 8 as the third largest value.  Below you will find the helpful folks of the Internet to have provided a PivotTable, an Array Formula solution, and I was finally able to do a simple formula one.   You can provide vba for the job should you insist we have everything, otherwise there is enough already.

I'm trying to apply a LARGE function to get the 5 largest values from a column ignoring duplicates. I did some searching around and found some proposed solutions but they don't seem to work for me. In my actual application the range is found by an array formula so I'm not sure if non array formulas will work here. My original function was {=LARGE(IF($A:$A=$A2,$B:$B),2)} dragged down the column. Replace 2 with 3 for the third largest, 4 for the fourth largest, etc. This worked except in the case of duplicates.  For example:  The data is in column 1 and the desired output is in column 2:  1    5  2    4 2    3 3    2  3    1 3 4 4 5   Things I have tried:   {=LARGE(IF(A:A < LARGE(A:A,i-1),A:A),1)} for the i-th largest value.    -Inputting this gives 3 for both i = 3 and i = 4. =LARGE(A:A,COUNTIF(A:A,MAX(A:A))+1)   -This doesn't seem to be any different than just LARGE(A:A,2) {=MAX(IF(A:A < LOOKUP(9.99999999999999E+307,A:A),A:A))}  -This does retrieve the value 4 but I'm not sure how to generalize it to the kth largest value.    VBA solutions are fine as well. I tried to code one myself but wasn't sure how to code in the array formula IF($A:$A=$A2,$B:$B).


If   $f : \mathbb{R} \rightarrow \mathbb{R}$ is a differentiable function and  $\lim\limits_{x  \rightarrow \infty} f'(x)^2 + f^3(x) = 0$ , show that $\lim\limits_{x\rightarrow \infty} f(x) = 0$.  I really have no clue how to start, I tried things like MVT and using definition of derivatives but I really can't figure this out.

Question:     Let $f$ be differentiable on $[0,+\infty)$, such as$$\lim_{x\to+\infty}\left([f'(x)]^2+f^3(x)\right)=0$$show that $$\lim_{x\to\infty}f(x)=\lim_{x\to\infty}f'(x)=0$$   I think this problem is similar to  and (the  background)  For my problem I guess that if  $$\lim_{x\to+\infty}\left([f'(x)]^{2m}+f^{2n+1}(x)\right)=0,m,n\in N^{+},n,m>1$$ then we have $\lim_{x\to\infty}f(x)=\lim_{x\to\infty}f'(x)=0$.


After I "properly eject" an external HDD or USB stick, can I "reconnect" it without physically unplugging it?

So I have unmounted a usb external hard drive but I went to re-mount it.  Is there a command that I can use to remount the drive?  Only way I know to re-mount a drive is to disconnect the usb cable from my Mac and reconnect it.


Let $H$ be a normal subgroup of $G$, and let $m=(G:H)$. Show that $a^m  \in H$ for every $a \in G$.   I have been thinking about this question for a few days but I get something informal.  What am I missing?   There are $m$ $H$-cosets. If we consider the cosets of $e$, $a$, $a^2$, $\cdots$, $a^{m-1}$, we get $m$ distinct cosets(actually I claim this without a valid proof, any hints?) Then the coset of $a^m$ should be one the above coset. (Then why must it be $eH$?)   Thanks in advance.

I am having a lot of trouble understanding the solution to this problem.   $(gH)^n = g^nH \implies g^n \in H$  Why does $H^n$ just turn into the identity? I am very confused, any help is appreciated.


Why is the privilege gap between 250 and 1000 so disproportionally large? I'm not taking about absolute difference as clearly the 5000 difference between 10000 and 5000 is larger but looking at a graph of the privileges gained up to 2500 rep, there's a disproportionally large jump from 250 to 1000.     Has the idea of adding/moving a privilege to 500 been considered? Why was it rejected?  There does seem to be a rough pattern of large increase, smaller increase between 20 rep and 2500 rep. I guess I could see this as kind of a "weeding out period" that attempts to dissuade users only in it for the rep but the rep itself (as opposed to the privileges) still increases and would partially mitigate that attempt.  Fair warning, I'm very close to 500 rep on my SO, so its entirely possible I'm biased.  Edit:  Just noticed . Did not see it earlier. My bad

As , the retag privilege serves a lot more confusion and a lot less of its benefit due to the suggested edit system. It must be done away with. It will be done away with. ♪  In light of this decided course of action, we're going to need a new snack for the road between "Create Tags" at 300 reputation and "Established User" at 1000 reputation. We'd like your help in thinking about some ideas on what would be a nice privilege to sit at this level. Since we're... a bit dry on our end.  The primary guideline in deciding what kind of privilege to put here is acknowledging its position in the overall hierarchy of privileges. 500 reputation is an early-intermediate user, one who has started to really get the hang of the site and its function. It can be something that provides convenience in how they currently can act on the site, or it could be some new functionality that fits as an early ability (especially considering there's no new abilities until 2000 reputation's "Edit Everywhat" ability).  I look forward to hearing what creative ideas y'all can provide.


I have a PNG file which is like a film strip of an animation all in 1 file.   Is is possible in Blender to render this file to make the animation work?    If not does anyone know how? The game it's from seems to do it and I've seen other models + animations work in programs like Blender / Photoshop before.  Probably cant but thought I'd ask.  Thanks

I'm trying to animate a mesh with different eye textures but it's not working.     This is a texture made by me to animate but I still couldn't figure out how to do it. I've seen tutorials on the internet but they don't work to me.


I don't want "www" in my domain. How do I set dns record so that when someone types www.mydomain.com it will just show up as mydomain.com?  I just want www to foward to root domain? Tried searching but google only tells me how to make my domain "www" which I do not want.  Is DNS even what I should be looking at?  Tool Tips is telling me, "The question you're asking appears subjective and is likely to be closed"...  Look, I don't know how to ask the question any different. I thought this could be done on a DNS level without messing with htaccess.  Any help would be appreciated.

I have this in my .htaccess (modified from the default Drupal .htaccess):  RewriteCond %{HTTP_HOST} ^www\.website.com\.com$ [NC] RewriteRule ^(.*)$ http://website.com/$1 [L,R=301]   In theory this will redirect something like http://www.website.com/asdf to http://website.com/asdf. However, it doesn't redirect, it allows requests to go through like there was no redirect intended.  (I'm on OS X if it matters, but I've also tried it on a Network Solutions Linux server with the same result.)


I was writing a regex match pattern, when I suddenly found out that preg_match_all isn't matching contents on a different line. What's up with that, and how do I fix it?   test1.php   $content = file_get_contents("test2.php"); preg_match_all("~startMatch(.+?)endMatch~", $content, $matches);  print_r($matches);    test2.php   startMatch text  endMatch    Results:   Array ( [0] => Array ( ) [1] => Array ( ) )    Expected Results:   Array ( [0] => Array ( [0] => startMatch text endMatch ) [1] => Array ( [0] => text ) )   However, we get the expected result, if startMatch text endMatch is on the same line. What's up with that? Don't periods in regex match all characters? How do I fix it?

For example, this regex  (.*)<FooBar>   will match:  abcde<FooBar>   But how do I get it to match across multiple lines?  abcde fghij<FooBar>


Let $\{a_n\}$, $\{b_n\}$ be sequences. Define $\displaystyle c_n=\sum_{k=1}^n a_kb_{n+1-k}$. Prove that if $~\sum a_n=A~$ , $~\sum b_n=B~$ , and $~\sum c_n=C~$ (so they are all convergent series) then $C=AB$. (Note that we do not need $\sum a_n$ to be absolutely convergent). Hello everyone. I am stuck on how to start this problem. I don't want the answer, just a hint on how to get started.

If $\sum a_n$ and $\sum b_n$ both converge and one of them absolutely then the Cauchy product $\sum c_n$ converges to $\sum a_n \sum b_n$. ($c_n = \sum_{k = 0}^n a_k b_{n - k}$), by Mertens Theorem.  Now, if both converge conditionally then the product does not have to converge as $a_n = b_n = (-1)^n/n$ shows. My question now is: What if $\sum a_n$ and $\sum b_n$ both converge conditionally and $\sum c_n$ converges, then is it always true that $\sum c_n$ converges to the product?  By the way, this is not homework, I'm already past the real analysis part.


Let $n$ be a positive integer where $n$ and $10$ are coprime number. Prove that then the last 3 digits of $n^\text{101}$ will be equal to the last 3 digits of $n$.   SOURCE: Bangladesh Math Olympiad  I basically know how to find the last digit of a base with a large exponent. Whatever the exponent in the event of one digit such as $1, 5, 6$ and $9$ will be, the last digit of the number will always result in that specific number which we have used.  So, the last 3 digit of $n$ can be constructed in $^4P_3$ ways with having that 4 digits $1, 5, 6$ and $9$ respectively. But how to determine only that distince value of $n$ and justify that the number and $10$ are coprime number>  The instruction of any kind of reference or any good books related with decimal expansion or number theory will be very helpful for me in the case of a beginner and some basic conception because there is no availability of satisfactory books written on number theory in our country which I have read some. Thanks in advance.

How do I efficiently compute $a^b\bmod c$:  When $b$ is huge, for instance $5^{844325}\bmod 21$? When $b$ is less than $c$ but it would still be a lot of work to multiply $a$ by itself $b$ times, for instance $5^{69}\bmod 101$? When $(a,c)\ne1$, for instance $6^{103}\bmod 14$?  Are there any other tricks for evaluating exponents in modular arithmetic?  This is being asked in an effort to cut down on duplicates, see  and .


Find all integers $k \geq 2$ such that $k^2 = 5k(\mod 15).$  Using arithmetic on $\mathbb{Z}_{15},$ $\bar{k}^2 = \bar{5}\bar{k},$ may I divide both sides by $\bar{k}$ to arrive at $\bar{k} = \bar{5}?$

The question is as follows:      Find all integers $k \geq 2$ such that $k^2 \equiv 5k \pmod{15}$.   I have an issue related to this question (its not about the solution to the question):  I know that $\overline{k} \in \mathbb{Z}_{15}$ is invertible if and only if $k$ and $15$ are relatively prime. So, assume $\overline{k}$ is invertible. Then, $\overline{k}^2 = \overline{5}\overline{k}$ implies $\overline{k} = \overline{5}.$ But isn't $\overline{5}$ not invertible, since $5$ is not relatively prime with 15? What am I missing?


In my day job I deal with alot of SQL Servers...and lately I've had a rash of clients running 16 cores but configured as 1 core per processor and their SQL Standard edition runs like a dog, as expected.  My question is this: Have you ever looked into what tends to be a better Processor-Core configuration? 1x8, 2x4, 4x4, 4x2, 8x1, etc. I know there are other aspects to this too around NUMA & 24+ cores on enterprise edition, increasing the CPU share in VMWare vs. increasing the CPU core count, etc.  I'm curious if you (or any of your fine friends) have looked into this and what the performance differences may look like as well as test results.  The software I work with typically has a minimum of 8 cores in SQL Server, some clients have 12 or 16, and a rare few outliers run even more.  Additional Details: -We start Cost Threshold for Parallelism to 50 or 75 depending on the scenario. -We change MAXDOP to 4 or 8 depending on the scenario. -We have an army of other changes that we make to SQL Server for best practices (for us).  This question about Processor-Core configuration has never really been dug into that I can recall.

I am requesting a new server from our Server team. Which is better for SQL Server performance: 2 CPUs with 8 cores per CPU or 1 CPU with 16 cores?


I used sudo dpkg --configure -a to repair an incomplete update. It solved at least most of the problems, but says   dpkg: error processing package linux-libc-dev:amd64 (--configure): package is in a very bad inconsistent state; you should reinstall it brefore attemping to configure it.   I entered sudo apt-get remove linux-libc-dev:amd64 and it removed some parts of the package and said:  dpkg: error processing package linux-libc-dev:amd64 (--remove): package is in a very bad inconsistent state; you should reinstall it brefore attemping a removal   How can I reinstall it?

I can't update my system because it freezes while installing a third-party update (zramswap-enabler)! Sometimes I get the following message in Update manager:  Could not initialize the package information An unresolvable problem occurred while initializing the package information. Please report this bug against the 'update-manager' package and include the following error message: E:The package zramswap-enabler needs to be reinstalled, but I can't find an archive for it.  I tried to remove the zramswap-enabler, but it's impossible because I get the following message: dpkg: error processing zramswap-enabler (--remove):  Package is in a very bad inconsistent state - you should  reinstall it before attempting a removal. Errors were encountered while processing:  zramswap-enabler E: Sub-process /usr/bin/dpkg returned an error code (1)  Actually I would really reinstall that package, but it is unable to do it! If I remove this third-party PPA then the system is warning me about a very very serious problem. So why can I not install/reinstall/remove/update this package and why freezes the updater if I try to update?


I saw this problem in a math competition and I have no idea how to solve it:  $$\sqrt{2 + \sqrt{2 + \sqrt{2 + \sqrt{2 + \cdots }}}}$$

(Fitzpatrick Advanced Calculus 2e, Sec. 2.4 #12)  For $c \gt 0$, consider the quadratic equation $x^2 - x - c = 0, x > 0$.  Define the sequence $\{x_n\}$ recursively by fixing $|x_1| \lt c$ and then, if $n$ is an index for which $x_n$ has been defined, defining  $$x_{n+1} = \sqrt{c+x_n}$$  Prove that the sequence $\{x_n\}$ converges monotonically to the solution of the above equation.  Note: The answers below might assume $x_1 \gt 0$, but they still work, as we have $x_3 \gt 0$.    This is being repurposed in an effort to cut down on duplicates, see here: .  and here: .


Using Ubuntu 14.04.1LTS. While trying to install VLC, it's throwing this error: "Package dependencies cannot be resolved" - it seems some packages are missing in order to install VLC.

Occasionally, when I'm installing stuff, I get an error like the following:  Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  package1 : Depends: package2 (>= 1.8) but 1.7.5-1ubuntu1 is to be installed E: Unable to correct problems, you have held broken packages.   How can I resolve this?


how to solve this problem?   Installation failed! Exit code: 256 Log: WoeUSB v@@WOEUSB_VERSION@@ ============================== Mounting source filesystem... Error: File "/media/woeusb_source_1551398248_10268/sources/install.wim" in source image has exceed the FAT32 Filesystem 4GiB Single File Size Limitation and cannot be installed.  You must specify a different --target-filesystem. Refer: https://github.com/slacka/WoeUSB/wiki/Limitations#fat32-filesystem-4gib-single-file-size-limitation for more info. Unmounting and removing "/media/woeusb_source_1551398248_10268"... You may now safely detach the target device

I tried to create a Windows 10 USB boot medium with WoeUSB. I formatted a USB drive with an NTFS partition, but WoeUSB complains with:  Installation failed! Exit code: 256 Log: WoeUSB v@@WOEUSB_VERSION@@ ============================== Mounting source filesystem... Error: File "/media/woeusb_source_1543626298_6098/sources/install.wim" in source image has exceed the FAT32 Filesystem 4GiB Single File Size Limitation and cannot be installed.  You must specify a different --target-filesystem. Refer: https://github.com/slacka/WoeUSB/wiki/Limitations#fat32-filesystem-4gib-single-file-size-limitation for more info. Unmounting and removing "/media/woeusb_source_1543626298_6098"... You may now safely detach the target device   I've also tried to start WoeUSB via command line, did not work.  sudo woeusb --partition Win10_1809Oct_English_x64.iso /dev/sdb   My iso is located in:     home/sawyer/Downloads/Win10_1809Oct_English_x64.iso  Thanks in advance! I've been trying to get windows installed for three nights now, so any help towards that goal is greatly appreciated.


I want to copy some archives offline in  archives folder, so please help me. Currently I am using ubuntu 13.04  And also suggest me how can I directly install software in Ubuntu like in Windows - offline. I am a new user on Ubuntu.

I have a friend who has got a computer that is not connected to the Internet. Is there any way to install software offline easily?


Which one is more preferable to write when you are writing an exam. Is it $\log(x)$ which denotes the natural logarithm or is it $\ln(x).$

Wikipedia :     The natural logarithm of $x$ is often written "$\ln(x)$", instead of $\log_e(x)$ especially in disciplines where it isn't written "$\log(x)$". However, some mathematicians disapprove of this notation. In his 1985 autobiography, Paul Halmos criticized what he considered the "childish $\ln$ notation," which he said no mathematician had ever used. In fact, the notation was invented by a mathematician, Irving Stringham, professor of mathematics at University of California, Berkeley, in 1893.   Apparently the notation "$\ln$" first appears in Stringham's book Uniplanar algebra: being part I of a propædeutic to the higher mathematical analysis.  But this doesn't explain why "$\ln$" has become so pervasive. I'm pretty sure that most high schools in the US at least still use the notation "$\ln$" today, since all of the calculus students I come into contact with at Berkeley seem to universally use "$\ln$".  How did this happen?


I want to make an app and publish it to the AppExchange and I want it to be available in both Classic and Lightning Experience. I went through   and through  . So the advice is to make a classic app and adjust Visualforce to comply with lightning design system. Is this the only way (using Visualforce and making it lightning ready) or I can create a "Lightning App" from the Lightning UI like on the image below:  and add Lightning pages to it? Will it also be "Lightning ready" app?  So my main confusion is the difference beween Lightning App and Lightning ready app. (by "Ligtning App" I don't mean the Aura Lightning Application which is a container for Lightning components, but the app like the one on the image above)  Can I create a Lightning app (by clicking on "New Lightning App") and publish it to AppExchange? If I can, will it be available in both Lightning experience and classic UI?

We are planning to submit our app in app exchange and we are currently in security review step. They have asked us to confirm that our app is lightning ready and asked us few screenshots of the app in lightning experience.   This is an integration app where we query SAP webservices and display it in visualforce pages. We used "datatable" to display the data in tabular format.    What are the fastest steps to be taken to confirm it is lightning ready? Is it just enough to check whether our app works in lightning environment or should we apply SLDS and modify the UI accordingly?? Our's is  an inline visualforce page used in account detail page  with datatable and page block table tags. We would like to know the modifications that has to be done in order to make it lightning ready? Since Pageblock table is not compatible in lightning do we have to modify the entire page?


In the chapter electromagnetic waves I was introduced with the concept of displacement current inside a capacitor. Since the region inside the capacitor is a dielectric there is no charge carriers in it. Then, what constitutes displacement current if it flows over there?   I know that it is a type of electric current formed by changing electric field.Conduction current involves flowing electrons and there is no electrons capable of moving about in a dielectric. But, then what is actually happening when we say displacement current?

What is a good way to think of the ? Maxwell imagined it as being movements in the aether, small changed of electric field producing magnetic field. I don't even understand that definition-assuming there is aether. (On the topic of which, has aether actually been disproved? I read that even with the Michelson-Morley experiment the aether wasn't disproved.)


Wolfram Alpha is able to telescope sums of the form $\sum (n+1)\cdots(n+k)$  e.g. $(1\cdot2\cdot3) + (2\cdot3\cdot4) + \cdots + n(n+1)(n+2)$  How does it do it?   EDIT: We can rewrite as: $\sum {(n+k)! \over n!} = \sum k!{(n+k)!\over n!k!} = \sum k!{{n+k} \choose n}$ (Thanks Daniel Fischer)  EDIT2: We can also multiply out and split sums. So e.g.  $$\sum (n-1)n(n+1) = \sum (n^3-n) = \sum n^3 - \sum n$$  But sums of powers actually seem to be more nasty than the original question, involving Bernoulli numbers. (Thanks Claude Leibovici)  And is there any name for this particular corner of maths? (i.e. How might I go about searching the Internet for information regarding this?)  PS please could we have a 'telescoping' tag?

Considering the following formulae:  (i) $1+2+3+..+n = n(n+1)/2$  (ii) $1\cdot2+2\cdot3+3\cdot4+...+n(n+1) = n(n+1)(n+2)/3$  (iii) $1\cdot2\cdot3+2\cdot3\cdot4+...+n(n+1)(n+2) = n(n+1)(n+2)(n+3)/4$  Find and prove a 'closed formula' for the sum  $1\cdot2\cdot3\cdot...\cdot k + 2\cdot3\cdot4\cdot...\cdot(k+1) + ... + n(n+1)(n+2)\cdot...\cdot (k+n-1)$  generalizing the formulae above.  I have attempted to 'put' the first 3 formulae together but I am getting nowhere and wondered where to even start to finding a closed formula.


I am looking for other solution of a problem, which I named: $$\text{Simple hit problem}$$ Let: $$y = \frac{a x + b}{c}$$ $$a, b, c, x \in \Bbb{Z}$$ For which $a, b, c$ there exists $x$ for such $y \in \Bbb{Z}$ ?  I noticed that the solution exists for $a, b, c$, if: $$(ax) \ \text{mod} \ c = c - (b \ \text{mod} \ c),$$ but the approach relies on checking all unique values of result of modulo operator from left side of equation.  The question is, if there exists any better approach for this problem or anyway it come down to check, if some equation will be true for some $x \in A$, where A will be a set of finite ammount of values ?

Isn't finding the inverse of $a$, that is, $a'$ in $aa'\equiv1\pmod{m}$ equivalent to solving the diophantine equation $aa'-mb=1$, where the unknowns are $a'$ and $b$? I have seem some answers on this site (where the extended Euclidean Algorithm is mentioned mainly) as well as looked up some books but there is no mention of this. Am I going wrong somewhere or is this a correct method of finding modular inverses? Also can't we find the Bézout's coefficients by solving the corresponding diophantine equation instead of using the extended Euclidean Algorithm?


I am glad to use the StackCodeSnippet on the site. Just a few question aroses in me.  Should a snippet like this display error messages, as my Browser debugger (as in the one pressing F12) does? I should then add it manually. It would be a great help for those watching my question, if it could be debuggeable on site!  What about some changes like these?

Currently, to see console.log() entries from StackSnippets, you need to open your browser console, and make sure it's recording from frames. Things could be a lot simpler if you would add a console to the snippets. Maybe something at the bottom of the snippet.  This could be done by overwriting the default console.log function with a custom one that both writes to the browser console (keep a reference to the original function), and also writes to the snippet's console.  EDIT: And perhaps also show errors thrown in this console.


How to show $\frac{3^n}{n!}\to 0$ without involving with series?  I tried squeeze theorem, but I can't find a sequence bigger than this one and converges to $0$.   Could someone suggest an idea?

Why is     $$\lim_{n \to \infty} \frac{2^n}{n!}=0\text{ ?}$$   Can we generalize it to any exponent $x \in \Bbb R$? This is to say, is     $$\lim_{n \to \infty} \frac{x^n}{n!}=0\text{ ?}$$     This is being repurposed in an effort to cut down on duplicates, see here: Coping with  duplicate questions.  and here: .


I'm flying from Singapore to Tel Aviv, Israel and will be transiting in Paris, France for about 2.5 hours via Air France. Do I need to apply transit visa?  Going back time is from Israel to Rome, Italy to Abu Dabhi and Singapore. Do I need to apply visa entering Rome and Abu Dhabi?  By the way, I'm working in Singapore and holding a Philippine passport.

I found many related questions on this site but I am still not sure about the rules. How can I decide if I need a visa to transit? Schengen members as of May 2021 are as follows:  Austria Belgium Czech Republic Denmark (excluding Greenland and the Faroe Islands - but an open border with the Schengen Area is maintained) Estonia Finland France (excluding overseas departments and collectivities) Germany Greece Hungary Iceland Italy Latvia Liechtenstein Lithuania Luxembourg Malta Netherlands (excluding Aruba, Curaçao, Sint Maarten and the Caribbean Netherlands) Norway (excluding Svalbard) Poland Portugal Slovakia Slovenia Spain (except Ceuta and Melilla) Sweden Switzerland


Everyone of us know about the . But I wonder, how the formula of $AB\sin\theta$ has been derived? Can anyone help?

I get the physical significance of vector addition & subtraction. But I don't understand what do dot & cross products mean?   More specifically,    Why is it that dot product of vectors $\vec{A}$ and $\vec{B}$ is defined as $AB\cos\theta$? Why is it that cross product of vectors $\vec{A}$ and $\vec{B}$ is defined as $AB\sin\theta$, times a unit vector determined from the right-hand rule?   To me, both these formulae seem to be arbitrarily defined (although, I know that it definitely wouldn't be the case).   If the cross product could be defined arbitrarily, why can't we define division of vectors? What's wrong with that? Why can't vectors be divided?


There is 2 definition about imaginary numbers:-   Imaginary unit, $i=\sqrt{-1}$ The square of Imaginary unit, $i^2=-1$   But the later is used mostly, as known to me, because of many reasons. And my question is from the later(2nd) definition. Now consider this:- $$      i^2=-1$$ $$=> (1) i=\sqrt{-1}   or               (2) i=-\sqrt{-1}$$ Now, $$     i=-\sqrt{-1}$$ $$=> i=-i    \text{   [from (1)]}$$  But actually $i$ cannot be equal to $-i$. So, where did I actually gone; where is my fault.

I know there must be something unmathematical in the following but I don't know where it is: \begin{align} \sqrt{-1} &= i \\\\\ \frac1{\sqrt{-1}} &= \frac1i \\\\  \frac{\sqrt1}{\sqrt{-1}} &= \frac1i \\\\  \sqrt{\frac1{-1}} &= \frac1i \\\\  \sqrt{\frac{-1}1} &= \frac1i \\\\  \sqrt{-1} &= \frac1i \\\\  i &= \frac1i \\\\  i^2 &= 1 \\\\  -1 &= 1 \quad !!? \end{align}


my question pertains to the trailing slash and no slash in domains and the correct method for setting this up in Google Webmaster tools. I have read all other threads on this site related to this question and still cannot understand what is correct for my situation - please help.  I recently created a new blog on Blogger and I registered the [http:// no "www" with no "/"] and [http://"www" with no "/"] with the latter () being nominated as my preferred domain.   However, I recently noticed that both URL versions (slash (“/”) and no trailing slash) of my domain address return a HTTP/1.0 200 OK status code, which according to Google (e.g. Search Engine Optimisation Starter Guide) is bad and will cause issues in terms of duplicate content and diluted links /split page rank.   From what I understand the method to rectify this is to create a 301 redirect from one to the other (depending on preference and/or performance).  My preference would be to use the "www" and no trailing slash, purely because I think most people would use this.  By the way, if I enter ["www" with no "/"] version of my domain in a browser bar it does not (at least I don't think it does) auto add the slash however, if I copy and paste the the domain elsewhere, it displays as [http://"www" with a "/"]?? Does this mean that I am NOT using the trailing slash? I am confused.  How do I let Google know that I want the NO trailing slash version of my site recognized as my preferred site? Or have I already done this, by nominating  as the preferred site? Unlike a WordPress site, I do not have access to a htaccess file. Or do I register the [http://"www" with a "/"] version in Google Webmaster tools and nominate my existing [http://"www" with no "/"] a second time as the preferred domain?  There is a redirect option in Blogger, but I think this is for pages and posts only…. I am not sure.  Otherwise how do I use the rel=canonical tag in my template to achieve this?  OR Do I need to nothing?  Apologies for all the information, I am fairly new to this and need help to understand.

My home page could be potentially linked as:  http://example.com http://example.com/ http://example.com/?ref=1 http://example.com/index.html http://example.com/index.html?ref=2  (the same page is served for all those URLs)   I am thinking about defining a canonical URL to make sure Google doesn't consider those urls to be different pages:  <link rel="canonical" href="/" /> (relative) <link rel="canonical" href="http://example.com/" /> (trailing slash) <link rel="canonical" href="http://example.com" /> (no trailing slash)   Which one should be used? I would just slap / but messing with canonical seems like a scary business so I wanted double check first.  Is it a good idea at all for defining a canonical URL for a home page?


I am asked to find the closed form solution for the below.  $$S_n = \frac{x}{1-x^2}+\frac{x^2}{1-x^4}+ ... + \frac{x^{2^{n-1}}}{1-x^{2^{n}}}$$  Just writing out the $S_1, S_2, S_3$, I have managed to find a pattern, which is:  $$S_n = \frac{S_{n-1}}{1-x^{2^n}} + \frac{x^{2^n}}{1-x^{2^{n+1}}}$$  I am not sure how to proceed onwards to solve this recurrence relation. Is there a clever trick I can do to solve it?

This is exercise 21 of Chapter 1 from Stein and Shakarchi's Complex Analysis.  Show that for $|z|<1$ one has $$\frac{z}{1-z^2}+\frac{z^2}{1-z^4}+\cdots +\frac{z^{2^n}}{1-z^{2^{n+1}}}+\cdots =\frac{z}{1-z}$$and   $$\frac{z}{1+z}+\frac{2z^2}{1+z^2}+\cdots \frac{2^k z^{2^k}}{1+z^{2^k}}+\cdots =\frac{z}{1-z}.$$  Justify any change in the order of summation.   [Hint: Use the dyadic expansion of an integer and the fact that $2^{k+1}-1=1+2+2^2+\cdots +2^k$.]  I don't really know how to work this through. I know that $\frac{z}{1-z}=\sum_{n=1}^\infty z^n$ and each $n$ can be represented as a dyadic expansion, but I don't know how to progress from here. Any hints solutions or suggestions would be appreciated.


That was probably a very confusing title, but I'm pretty confused. I am making a game, and there are explosions. I just ran into this one stupid problem. Here's my code for the explosions (without the package and imports):  public class LBExplosion extends GameObject{ private int tick; private int startSize,endSize,size; Handler handler; public LBExplosion(float x, float y, ID id, int startSize, int endSize, Handler handler) {     super(x, y, id);     // TODO Auto-generated constructor stub     this.startSize = startSize;     this.endSize = endSize;     size = startSize; }  @Override public void tick() {     // TODO Auto-generated method stub     tick++;     size++;     if (size >= endSize) {         this.handler.removeObject(this); //here     } }  @Override public void render(Graphics g) {     // TODO Auto-generated method stub     if (tick % 2 == 0) {         g.setColor(Color.white);     } else if (tick % 2 == 1) {         g.setColor(Color.red);     }     g.fillRect((int) x - size/2, (int) y - size/2, size, size); }  @Override public Rectangle getBounds() {     // TODO Auto-generated method stub     return null; }   }  And it errors when I try to remove it (at line 25).  Here's the code for the handler class (without the package and imports):  public class Handler { LinkedList <GameObject> objList = new LinkedList <GameObject>();  public void tick() {     for (int i = 0; i < objList.size(); i++) {         GameObject tempObject = objList.get(i);         tempObject.tick();     } } public void render(Graphics g) {     for (int i = 0; i < objList.size(); i++) {         GameObject tempObject = objList.get(i);         tempObject.render(g);     } }  public void addObject(GameObject object) {     objList.add(object); } public void removeObject(GameObject object) {     objList.remove(object); } public void removeAllEnemies() {     for (int i = 0; i < objList.size(); i++) {      } }   } And here's the constructor for the game class (where it's spawned):  public Game() {     handler = new Handler();     hud = new HUD();     spawner = new Spawner(handler);      this.addKeyListener(new KeyInput(handler));     new Window(WIDTH,HEIGHT,"Game", this);      handler.addObject(new Player (16, 16, ID.Player,hud,handler));     handler.addObject(new LBExplosion (300, 316, ID.LBExplosion,0,64,handler));  }   It gives me this error:  Exception in thread "Thread-2" java.lang.NullPointerException at com.wave.noah.two.p.a.c.k.a.g.e.something.main.LBExplosion.tick(LBExplosion.java:26) at com.wave.noah.two.p.a.c.k.a.g.e.something.main.Handler.tick(Handler.java:12) at com.wave.noah.two.p.a.c.k.a.g.e.something.main.Game.tick(Game.java:80) at com.wave.noah.two.p.a.c.k.a.g.e.something.main.Game.run(Game.java:62) at java.lang.Thread.run(Unknown Source)   Don't mind the long package name.  How do I fix this unexpected error?

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


A long time ago I was told that the universe is finite. The provided "proof" (or reasoning), known as , was that on infinite universe there would be an infinite number of stars, and that an infinite number of stars in night sky would make the sky bright.  I guess this sounds reasonable, but I have some doubts. If we assume that universe really is infinite and that it has infinite number of stars spread somewhat uniformly on the space, how would one prove (or disprove!) that the night sky really would be bright? What assumptions one would need to make on the way constructing the proof?  I am not looking for a "correct" answer but how to approach the claim mathematically.

How can the universe become infinite in spatial extent if it started as a singularity, wouldn't it take infinite time to expand into an infinite universe?


Here is what I have now:   console.log(JSON.stringify(errorParam))  {"data":{"message":"{\"ErrorLine\":113,\"ErrorMessage\":\"Authentication Failed\",\"ErrorNumber\":50004,\"ErrorProcedure\":\"start_test\"}"},"status":400,"statusText":"Bad Request"}   I know about JSON.stringify but how can I convert this back into an object from a string?

Given a string of JSON data, how can I safely turn that string into a JavaScript object?  Obviously I can do this unsafely with something like:  var obj = eval("(" + json + ')');   but that leaves me vulnerable to the JSON string containing other code, which it seems very dangerous to simply eval.


I recently interviewed for and was issued an immigrant visa to the US for me and my family. Currently we are residing in Dubai.  Can we travel to the US from Dubai even though our visa was issued by the US Embassy in India?

I am an Indian with a valid B1\B2 visa, currently residing in Sweden. Can I travel to the US from Sweden or do I have to go through India?


Various commentators have suggested that one of the reasons knowledge of the Jedi dies out so fast in Rogue One is that there were so few Jedi compared to the wider galactic population (I believe I've seen one post here that talks about a trillion people on Coruscant and around 100,000 Jedi in the galaxy). However it's also known in-universe that every child is tested for their midichlorian count. If true, then this suggests it was done covertly, otherwise the conversation would go something like:  "We're going to just check his Midichlorian count now, Mr Fett" "His what? You're doing what now? Hands off my Boba!"  [screaming]  So is there any indication whether testing was done overtly or covertly?

Training of  ranged between the ages of 4 and 8 but at what age was a Jedi able to feel a Force sensitive child? Is it from birth or at around 4 years?