If $mn$ distinct numbers are entered into an $ m \times n$ board. If $k$ largest numbers in each row $(1 \leq k \leq  m)$ are underlined, and $x$ largest numbers in each column $(1 \leq x \leq n)$ are underlined, prove that there were at least $kx$ numbers which were underlined twice. How would I go about attacking this problem?  At first I tried a couple test cases, but was not able to determine a pattern from them. Any help is greatly appreciated.

This is a question from a very old American Mathematical Monthly, if I recall correctly. It has a very nice solution and illustrates an often useful technique. If it is unsolved after a while, I will post a solution.  The integers $1,2,\ldots,225$ are arranged in a $15\times 15$ array. In each row, the five largest numbers are colored red, and in each column, the five largest numbers are colored blue. Prove that there are at least $25$ numbers colored both blue and red (purple, if you will).  Edit: Since there have been no attempts yet, I'll give a hint. Try to make the question "harder" first.


in "Oracle Certifi ed Associate Java SE 8 Programmer I Study  Guide" speaking about passsing by value , saying :  Calling methods on a reference to an object does affect the caller     public static void main(String[] args) {     StringBuilder name = new StringBuilder();     speak(name);     System.out.println(name); // Webby     }     public static void speak(StringBuilder s) {     s.append("Webby");     }   In this case, the output is Webby because the method merely calls a method on the parameter. It doesn’t reassign name to a different object.    So what does this mean? I didn't get it. Shouldn't there be 2 different objects?

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?


Two players play the game: There are two bowls, each of which can be fitted by some number of coins.   In the beginning the first player puts in the first bowl some natural number of coins of his choice. Then the second player, knowing how many coins the first put, puts in the second bowl some natural number of coins of his choice. Then, starting with the first player, each player makes one of the three possible moves:   Take any number of coins from the first bowl Take any number of coins from the second bowl Take the same number of coins from both bowls   Both players know how many coins lying in bowls at a time. The winner is the player, after which there will be no progress in the two bowls of coins.  The first player has put in the first bowl 100 coins. How many coins you need to put as the second player in the second bowl to win the game with the right playing of both players?

Rules of the game with two players.  First player puts any number of coins in the first pot. Then second player, knowing that number, puts any amount of coins in the second pot.  Then they in turns (beginning with the first player) do one of these things: take any amount of coins from one pot OR take equal amount from both pots. Whoever cannot take a coin loses. Players always know how many coins there are in the pots.  Who wins and what is the perfect strategy?  I managed to solve it, but the solution is very complicated and is based on fact which I just randomly guessed, but cannot deduct without the full solution. So I am looking for a nice approach to this problem.  The easy part is determining that player two wins: if there is a smallest winning initial donation by the first player, then the first move of player one cannot be taking just from the second pot, and this fact leads to infinite count of winning positions for player two for bounded number in the first pot, which is impossible (since there cannot be two winning positions for player two with the same amount of coins in the first pot).


Hey guys I can't for the life of me get the button to go to the bottom of the container using flexBox. I have tried multiple different things, and for some reason, it's being stubborn. I've actually used flexBox quite a bit so I am confused on why I am running into so much trouble. The button is currently in the middle of the DivCont with the background colorWhite. Here is my code and you can see on the bottom I even tried adding a div around the third button to test it out... Excuse the justify contentflex-end' spam import React from "react"; import { makeStyles } from "@material-ui/core/styles";  import { Link } from "react-router-dom";  const useStyles = makeStyles({   divCont: {     backgroundColor: "white",     display: "flex",     width: "250px",     height: "250px",     borderRadius: "10px",     margin: "40px",     flexDirection: "column",   },   button: {     display: "flex",     justifyContent: "flex-end",     alignContent: "flex-end",     alignItems: "flex-end",   },   mainCont: {     display: "flex",     flexDirection: "row",     justifyContent: "center",     alignItems: "flex-end",     alignContent: "flex-end",   },   h2: {     fontWeight: "normal",     display: "flex",     justifyContent: "center",   },    p: {},   buttonCont: {     display: "flex",     justifyContent: "flex-end",     alignItems: "flex-end",     alignContent: "flex-end",   }, });  export default function HomeMeunuGrid() {   const classes = useStyles();    return (

         {" "}
Custom Tubmlers

Hello to the world
         <button className={classes.button}>Click me</button>

Affordable Prices

 Hello to the world
         <button className={classes.button}>Click me</button>

Family Owned

 Hello to the world

           <button className={classes.button}>Click me</button>

   ); }

Given the following HTML:

     Copyright Foo web designs

    I would like #copyright to stick to the bottom of #container. Can I achieve this without using absolute positioning?


I am trying to call a new function under existing function. First function works perfectly, but code does not go inside test function. Any idea on this issue?  The error I get on this is : test is not defined    var doIt; var test;  $(document).ready(function() {   test(2);   doIt = function() { //now has global scope.     test(1);   };    test = function(n) {     alert('test function');   } }) <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <body>   <input name="Go" type="button" value="Go" onclick="doIt();" /> </body>

I've recently started maintaining someone else's JavaScript code. I'm fixing bugs, adding features and also trying to tidy up the code and make it more consistent.  The previous developer used two ways of declaring functions and I can't work out if there is a reason behind it or not.  The two ways are:  var functionOne = function() {     // Some code };     function functionTwo() {     // Some code }   What are the reasons for using these two different methods and what are the pros and cons of each? Is there anything that can be done with one method that can't be done with the other?


When we describe a pie chart that gives information about percentage of common reasons for travel to a country, which of these two is correct?  As it is mentioned above, half of visitors has a trip for vacation As it is mentioned above, half of visitors have a trip for vacation

What’s the right version of these two?   Half of the students doesn’t bother to show up.  Half of the students don’t bother to show up.    Or are both right?  The related question  discusses some relevant concepts, but the answer is very general, and it's not clear how to apply it here since "half" is a singular noun, while "two" is a plural noun.   Barrie England's answer there says that in "2/3 of the pizza was eaten," singular agreement is appropriate because "the emphasis is likely to be on the amount of pizza eaten, and not on the number of individual thirds. In contrast, in [2/3 of the visitors were men] the emphasis is on the number of visitors who were men, so plural concord ... is required."  What does it mean to put "emphasis" on "the amount" vs. "the number"?  If "half of the students" is just an approximate or uncertain percentage (like "between 51% and 55%"), rather than an exact count, how do I know whether it's appropriate to emphasize the amount or the number of students?


Be $n>1$ and $x_1,...,x_n \in \mathbb{R}$ show per Induction with  $n \in \mathbb{N}$ $ V_n(x_1,...,x_n) := det\begin{pmatrix} 1 & x_1 & x_1^2 & ... & x_1^{n-1} \\ 1 & x_2 & x_2^2 & ... & x_2^{n-1} \\ ... & ... & ... & ... & ... \\ 1 & x_n & x_n^2 & ... & x_n^{n-1} \end{pmatrix} = \prod \limits_{i>j}(x_i - x_j) $ so i haven't done induction with matrices before. My idea is to split them into smaller parts like det(AB)=det(A)det(B), but im missing some knowledge. Im here completely lost.

For $n$ variables $x_1,\ldots,x_n$, the determinant $$  \det\left((x_i^{j-1})_{i,j=1}^n\right) =   \left|\begin{matrix}      1&x_1&x_1^2&\cdots & x_1^{n-1}\\      1&x_2&x_2^2&\cdots & x_2^{n-1} \\      \vdots&\vdots&\vdots&\ddots&\vdots\\      1&x_{n-1}&x_{n-1}^2&\cdots&x_{n-1}^{n-1}\\      1 &x_n&x_n^2&\cdots&x_n^{n-1}   \end{matrix}\right| $$ can be computed by induction; the image below says it shows that. I have done this before, if I submit this will I get marks?   MORE IMPORTANTLY how do I do it by induction? The "hint" is to get the first row to $(1,0,0,...,0)$.  I think there are the grounds of induction in there, but I'm not sure how (I'm not very confident with induction when the structure isn't shown for $n=k$, assume for $n=r$, show if $n=r$ then $n=r+1$ is true.  By the way the question is to show the determinant at the start equals the product $$\prod_{1\leq i<j\leq n}(x_j-x_i)$$ (but again, explicitly by induction)


I've been trying to use GRASS r.fill.dir to get a filled DEM but I get the error:  The following layers were not correctly generated.   I tried using SAGA Fill Sinks, that worked. I get the same error on every GRASS tool I use.  QGIS version 3.12.0-București

I updated QGIS to version 3.6 using OSGEO4w  When I try to run any GRASS script, I get the following error message :        This algorithm cannot be run :-(  The specified GRASS 7 folder   "C:\OSGEO4~1\bin\bin" does not contain a valid set of GRASS 7 modules.   Please, go to the Processing settings dialog, and check that the GRASS   7 folder is correctly configured   It looks like the path doesn't exist, but I couldn't find a place to change it; it is not an option in the processing settings any more like in versions 2.x.   Is there a way to run those processing scripts in QGIS 3.6 and if so, how could I tweak the settings needed?     Edit : Here is what my processing options looks like


After these number of explosions in different cities in Turkey, including an explosion at the heart of Istanbul’s old city, an area visited by up to 14 million tourists each year. Is it still safe to travel to Istanbul ? As for me, I've already bought my plane ticket for my next visit (in summer 2016), and I'm looking forward to it. but now, I became really worried and confused. Should I just forget all these explosions and travel or should I cancel my ticket and seeking another place to travel ?

When planning a trip, I like to make sure I will feel safe enough (I am talking about war/terrorism risk, not pickpockets), or at least I like to have an idea about the risks. I know the risk could be subject to political views (for example the political stability of a region might not be acknowledged by every country) and therefore I am mostly interested in a Western country view.  In order to figure that, I thought about checking travel operators offers. I suppose if they do not organise trips to a specific region, it might be due to political instability risks. But it might be due to a lack of tourist interest too. As I tend to travel without their help, I am not really considering this kind of source as very helpful.  So I am interested in one (or two, for cross-checking) source(s) of information with a western view (I mean I understand the view could be biased) regarding the security of ideally any area in the world. My expectation is that, the same way I can browse a tour operator's catalog of visited areas, I could browse through the areas and see if it is recommended or not to travel there.


what is this? actually its the first photo of light as wave and a particle.   The bottom "slice" of the image shows the particles, while the top image shows light as a wave.  i have questions  1.how this experiment was conducted. Explain it briefly.  2.how this proves the duality.  3.how does this ripples show the duality nature of light.

I just came across  where they are claiming that they have photographed light behaving both as a wave and a particle!  The paper has been published in Nature Communications and I read the  which says,     Surface plasmon polaritons can confine electromagnetic fields in   subwavelength spaces and are of interest for photonics, optical data   storage devices and biosensing applications. In analogy to photons,   they exhibit wave–particle duality, whose different aspects have   recently been observed in separate tailored experiments. Here we   demonstrate the ability of ultrafast transmission electron microscopy   to simultaneously image both the spatial interference and the   quantization of such confined plasmonic fields. Our experiments are   accomplished by spatiotemporally overlapping electron and light pulses   on a single nanowire suspended on a graphene film. The resulting   energy exchange between single electrons and the quanta of the   photoinduced near-field is imaged synchronously with its spatial   interference pattern. This methodology enables the control and   visualization of plasmonic fields at the nanoscale, providing a   promising tool for understanding the fundamental properties of   confined electromagnetic fields and the development of advanced   photonic circuits.   They do not really talk about photographing light but instead they seem to talk about . The  says that the "polariton" is a quasiparticle. However, they still claim to have photographed light behaving both as a wave and a particle.  Is this a valid interpretation of the experiment?


I want to select max date from may layer by below query in my Web GIS but I cannot.  (SELECT MAX( GregorianDate ) FROM DrillingProgress WHERE Crew = 'c-Chabock')

In ArcGIS 10.1 I am trying to do a Definition Query that will select the records that are the min values from a table.  I try a lot of type of query like and it still not working. Name table is Polygone_Buffer_Output Attribute : Air_Mil  "Air_Mil" = (SELECT MIN( "Air_Mil" ) FROM "Polygone_Buffer_Output"  [Air_Mil] = (SELECT MIN( [Air_Mil] ) FROM "Polygone_Buffer_Output"  [Air_Mil] = (SELECT MIN( [Air_Mil] ) FROM [Polygone_Buffer_Output]  "Air_Mil" in (SELECT MIN( "Air_Mil" ) FROM "Polygone_Buffer_Output"


I was wondering this morning why I was 3 rep less and then I tracked it down to this recent activity:  -3  10 hours ago    removed     Using Kendo upload to extract txt file data and record to a database   There was no downvote or any explanation provided, just that the question was "removed". Not only did I lose the reputation I had earned from this question, but last I remember, I was still interested in an answer for future reference.  Can someone please explain what happened and why my question was deleted?

What circumstances can cause a question or answer to be deleted, and what does that actually mean?    How can a post be deleted? When can't I delete my own post? Can I still see my post even after it's deleted? Can I see a list of my deleted posts? How can I undelete one of my posts? What does deletion mean for a post? How do votes to delete work? What are the criteria for deletion? What else should I know about deleted posts? If I flag my question with a request to delete it, what will happen?       For more information, see the articles about  and  in the .


I saw a graph in a geology class that showed stability fields of elements. something similar to the one below. I noticed there were no elements that had a few protons but tons of neutrons. I was curious why that was so I asked my prof why that was and he also was curious. So now I'm asking you dear reader!! why are there like no stable elements with few protons and many neutrons?

In basic chemistry, we are taught that an atom has roughly the same number of neutrons and number of protons, this doesn't seems to hold for larger atoms, but it is always roughly proportional (i.e. you seldom find an atom with 100 protons but 1 neutron, that just does not happen). Why is that?


In the Harry Potter series, wouldn't the Elder Wand belong to Neville, not Harry? Since it belonged to Dumbledore, then Snape killed him, then Nagini killed Snape, then Neville killed Nagini, wouldn't it belong to him instead?

Voldemort ordered Nagini to kill Snape in hopes of claiming the Elder Wand's ownership.  Let's suppose that Snape was indeed the owner.  In this scenario, would the Elder Wand's ownership truly pass to Voldemort?  I ask this because, after all, the one who overpowered Snape was Nagini, not Voldemort.   Voldemort ordered Nagini to kill Snape. However, this would be equivalent to ordering a Death Eater to kill Snape, in which case the Death Eater would gain the ownership - in a similar manner, Nagini is the murderer. Nagini isn't a "spell": remember how Draco summoned a snake to attack Harry back at CoS? If that snake kills Harry, I'd imagine that Draco gains the ownership (if Harry had the Elder Wand) because that snake was a "spell" casted by Draco - but this time is different, because Nagini isn't a "spell" casted by Voldemort, but rather an actual third-party creature.   The curious thing is that Voldemort did cast some sort of spell (he flicked his wand), which I think caused Nagini's barrier to break so Nagini could kill Snape. In some way, Voldemort did provoke Snape's death - however, it was mostly indirectly.  So, would the ownership pass to Nagini or to Voldemort? If it passes to Nagini, would the Elder Wand's "ownership cycle" end, or would it continue if Voldemort decides to kill Nagini?    The simplified version of this question is: if an animal kills the owner of the Elder Wand, what happens to its ownership?


s = [[0]*3]*3  i = 0  while i < 3:     j = 0     while j < 3:         print(s[i][j])         s[i][j] += 1         j += 1     i += 1   The printed result of the above code really confused me, Why the second and third column of the array become [1,1,1] and [2,2,2] but not [0,0,0]?

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?


Prove that $n=\dfrac{5^{125}-1}{5^{25}-1}$ is a composite number   My attempt,  Let $x=5^{25}$, so that $5^{125}-1=x^5-1=(x-1)(x^4+x^3+x^2+x+1)$  $=(x^4+9x^2+1+6x^3+6x+2x^2-5x^3-10x^2-5x)(x-1)$  $=((x^2+3x+1)^2-5x(x+1)^2)(x-1)$  I'm stuck at this point and don't know how to continue anymore. Hope someone can provide a detailed solution. Thanks a lot.

Prove that   $\dfrac {\left( 5^{125}-1\right)}{\left( 5^{25}-1\right)}$ is composite number using number theory. Do not use calculator or Wolfram alpha or anything like that.


If an observer passes an electron, in such a way that the observer is accelerating, the observer would see photons because accelerating charges induce electromagnetic waves.  But from point of view of the electron or an inertial observer there is no magnetic field nor an acceleration which could 'produce' an electromagnetic wave.  So for the first observer there exists a photon but not for the second observer. How is this possible, are photons relative?

At the end of this nice video (), she says that  is a chain reaction of electric and magnetic fields creating each other so the chain of wave moves forward.  I wonder where the  is in this explanation. What is the relation between electromagnetic wave and photon?


Like what i am demonstrating here. To be honest i didn't even know about it until much later when i discovered the Grammarly app and i was like "it even exists?". Now it has quite become my bad habit especially in real-time messaging. I am aware that it is incorrect but when the conversation is going fast i just kind of forget to give it one more keypress and bam there goes my grammar.  Again forgive me if the passage above sounds rude or something. I just want to clarify it once and for all.

I frequently edit questions on StackOverflow, and I always fix the "i" into "I". See this .     When i I start my tomcat, i I am getting this problem.   How could i I resolve this problem.   Am I right to do so?     points out an interesting thread illustrating that debate:    the MetaSO question "" (and ):      The point of text on a site like this is to communicate.   Why do you want  to make it harder to communicate than it has to be?   You may like writing with no capitalization, but I think it's pretty clear that people prefer reading with capitalization.   If you don't care about making life easier for those trying to help you, why do you think anyone will bother helping you in the first place?    The article "" also refers to norms.      Readers of the modern English language have grown accustomed to certain norms. Paragraphs, for one. Punctuation. Consistent spelling. And, of course, capitalization.


article talks about de-arrangement in permutation combination.     Funda 1: De-arrangement      If $n$ distinct items are arranged in a row, then the number of ways they can be rearranged such that none of them occupies its original position is,   $$n! \left(\frac{1}{0!} – \frac{1}{1!} + \frac{1}{2!} – \frac{1}{3!} + \cdots + (-1)^n \frac{1}{n!}\right).$$      Note: De-arrangement of 1 object is not possible.      $\mathrm{Dearr}(2) = 1$; $\mathrm{Dearr}(3) = 2$; $\mathrm{Dearr}(4) =12 – 4 + 1 = 9$; $\mathrm{Dearr}(5) = 60 – 20 + 5 – 1 = 44$.   I am not able to understand the logic behind the equation. I searched in the internet, but could not find any links to this particular topic.  Can anyone explain the logic behind this equation or point me to some link that does it ?

I understand the whole concept of Rencontres numbers but I can't understand how to prove this equation  $$D_{n,0}=\left[\frac{n!}{e}\right]$$  where $[\cdot]$ denotes the rounding function (i.e., $[x]$ is the integer nearest to $x$). This equation that I wrote comes from solving the following recursion, but I don't understand how exactly the author calculated this recursion.  $$\begin {align*}  D_{n+2,0} & =(n+1)(D_{n+1,0}+D_{n,0}) \\ D_{0,0} & = 1 \\ D_{1,0} & = 0  \end {align*} $$


I am new to Ubuntu. I have installed Ubuntu MATE in my p.c. Now when I opened browser Mozilla Firefox it searched for a update. So I have been updating it but it fails every time.  sudo apt update works well.  sudo apt upgrade throws this error:  E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?   How can I update all the applications in Ubuntu MATE as well as Mozilla Firefox?

I get this error when trying to use apt-get:  E: Could not get lock /var/lib/dpkg/lock - open (11 Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/) is another process using it?     How can I fix this?


What I mean by "stencilled" artwork is cartoonish glyphs for the background of a graphic, visible on  or in the  the  in the top banner.  More than willing to pay, just haven't come across something like this.

I am looking for good websites providing royalty free stock images for pay.  I'm not looking for sites that make images available for free and require attribution or non-commercial use; they're already covered in .  I'd also like hear some comments of the service:   What kind of payment options they offer?   e.g. do you have to buy a bulk of credits or can items be bought separately? Sometimes buying bulk credits won't suit my projects.  How much do they have content?   e.g.  is interesting  for its payment options, but I found its supply lacking.  How is the overall content quality?   e.g. does the site have vast disperse in quality, which usually is the case with big, major sites (such as  or does the site have strict quality requirements?    What sites do you use to buy graphics / backgrounds / images for commercial design purposes?


I'm looking for a possibly derogatory noun that describes a person who changed their view from what they believed before. It could also be used to describe a person who expresses different views to different people when asked about the same issue. For instance: Ben always says that landing on the moon was real, but when talking to Melissa, he suddenly says that it was faked. He's such a ______. I've tried googling this word, but "fickle" is the only one I can find. "Double standards" does describe the view, but I vividly remember there being a noun to describe a person like this. I saw a  post related to this a while ago as well. It said something along the lines of "Changing your mind doesn't make you a ______, it means you've grown." I'm fairly certain the word ended in -ist as well, but those are all the details I can recall.

What do we call a person who keeps switching his stance on a topic during a discussion involving various sentences. What I mean is the speaker rejects something while accepting it indirectly. "Inconsistent" seems really close in a general sense. But he rejects it directly and again accepts it indirectly ( and I don't know he realizes that or not) again and again during a discussion.   I want it to have a neutral connotation as the person seems to be confused with his own ideas yet claiming to be right but we never know what are his intentions. Also it would be nice have a "politically correct" word for this.  I am not able to phrase the exact sentence because it is from another language and I need an English word for this activity/person. So every one is welcome to edit the question and add appropriate example sentences.


I have a Google Docs form that I use to track my customers complaints. I want my customers to have a complaints number when I'm talking with them.  Is it possible to have a "counter" field pre-fill with an incremental number?

Is it possible in Google Forms to give a unique value to each row it inserts into the spreadsheet as well as the timestamp?


I created a directory d and a file f inside it. I then gave myself only read permissions on that directory. I understand this should mean I can list the files (e.g. ), but I can't.  will@wrmpb /p/t/permissions> ls -al total 0 drwxr-xr-x   3 will  wheel  102  4 Oct 08:30 . drwxrwxrwt  16 root  wheel  544  4 Oct 08:30 .. dr--------   3 will  wheel  102  4 Oct 08:42 d will@wrmpb /p/t/permissions> ls d will@wrmpb /p/t/permissions>   If I change the permissions to write and execute, I can see the file.  will@wrmpb /p/t/permissions> chmod 500 d will@wrmpb /p/t/permissions> ls d f will@wrmpb /p/t/permissions>    Why is this? I am using MacOS.  Edit: with reference to @ccorn's answer, it's relevant that I'm using fish and type ls gives the following:  will@wrmpb /p/t/permissions> type ls ls is a function with definition function ls --description 'List contents of directory'     command ls -G $argv end

In my CMS, I noticed that directories need the executable bit (+x) set for the user to open them. Why is the execute permission required to read a directory, and how do directory permissions in Linux work?


I have a Canon 70D with a Canon Speedlite 580EX II.  This may be a duplicate question, but I can't find the answer.  I can't get the flash to go off in live view mode, either the external flash or the pop up flash.  Is this a setting within the camera that I need to adjust in order for the flash to fire?

I had the opportunity to use some professional flashes yesterday and I found out that they didn't fire when I was trying to shoot with the camera in Live View mode.  The flashes were two Elinchrom FX400, one wirelessly synchronized with the camera and the other was activated automatically when the first one fired (With a photocell or something).  Using the camera normally fired both flashes at the same time with no issues, but live view mode deactivated both. Why the LV mode is incompatible? Am I missing something?  By the way, I tried this with two cameras, a Canon 1000D and a 550D.


I am trying to create search menu in my website, i am using php and mysqli ,i have created all the credential stuffs which are all required to it but still it showing me some errors,can anyone help me from this. analyze.php    <!DOCTYPE html>         <title>Gtec NetWork</title>     <meta name="viewport" content="width=device-width, initial-scale=1.0">          <link href="asset/bootstrap/css/bootstrap.min.css" rel="stylesheet" media="screen">

             GTEC Network

Home

Boys

Girls

                     <form method="POST" action="search.php">                     Search                             <input type="text" name="keywords" >                             <input type="submit" class="btn btn-primary lg" value="Search">                                                   </form>

        search.php  <?php       require_once 'lib/db.php'; ?><?php     if (isset($_GET['keywords'])) {         $keywords = $db->escape_string($_GET['keywords']);         $query = $db->query("             SELECT *             FROM user              WHERE  registernumber LIKE '%{$keywords}%'             OR username LIKE '%{$keywords}%'              "             );         $run = mysqli_query($query);      }  ?>     <!DOCTYPE html>         <title>Gtec NetWork</title>     <meta name="viewport" content="width=device-width, initial-scale=1.0">          <link href="asset/bootstrap/css/bootstrap.min.css" rel="stylesheet" media="screen">

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Girls

                 Found<?php echo $query->num_rows;?> results.                 <?php                       if ($query->num_rows) {                         while($r = $query->mysqli_fetch_array())                         {                         ?>
                             <?php echo $r->username;?>
                         <?php   }                     }?>

         The problem is  Found Notice: Undefined variable: query in C:\xampp\htdocs\php\search.php on line 39  Notice: Trying to get property of non-object in C:\xampp\htdocs\php\search.php on line 39 results.  Notice: Undefined variable: query in C:\xampp\htdocs\php\search.php on line 41  Notice: Trying to get property of non-object in C:\xampp\htdocs\php\search.php on line 41  Please help me

So I'm refactoring my code to implement more OOP.  I set up a class to hold page attributes.  class PageAtrributes  {   private $db_connection;   private $page_title;      public function __construct($db_connection)      {         $this->db_connection = $db_connection;         $this->page_title = '';     }      public function get_page_title()     {         return $this->page_title;     }      public function set_page_title($page_title)     {         $this->page_title = $page_title;     } }   Later on I call the set_page_title() function like so  function page_properties($objPortal) {         $objPage->set_page_title($myrow['title']); }   When I do I receive the error message:     Call to a member function set_page_title() on a non-object   So what am I missing?


I'm writing this in Ubuntu 16.04.5 LTS. I'm looking at Gnome Extensions for Ubuntu 18.04 that work with Gnome version 3.24 and breaks with version 3.26.  How can I find out using browser (google search doesn't tell me), apt list | grep ... or other means what version of Gnome Ubuntu 18.04 is using today?  Rebooting every time I want to know something about a version I haven't booted is inconvenient.    Test Results:  zcat /dev/nvme0n1p10/usr/share/doc/gnome-session-bin/changelog.Debian.gz | head -n1 gzip: /dev/nvme0n1p10/usr/share/doc/gnome-session-bin/changelog.Debian.gz: Not a directory   Important Note: I do not have 18.04 installed. I have 18.04 Unity installed. I want to know current known version would be installed so I can research bugs before installation.    EDIT: I'm not looking for the Gnome version of the current booted partition (as the duplicate candidate does) using:  $ apt-cache policy gnome-shell gnome-shell:   Installed: (none)   Candidate: 3.18.5-0ubuntu0.3   Version table:      3.18.5-0ubuntu0.3 500         500 http://ca.archive.ubuntu.com/ubuntu xenial-updates/universe amd64 Packages      3.18.4-0ubuntu3 500         500 http://ca.archive.ubuntu.com/ubuntu xenial/universe amd64 Packages   I'm looking for the gnome version for a partition that needs to be mounted first (18.04). Or simply a link to a website containing the current version numbers as of today for 14.04, 16.04, 18.04, etc.

Is there a way I can see all the versions that are in the archives that I have configured in sources.list. I can see the last version of each archive withapt-get policy, but how can I see them all?  Is there any way that this can also include PPA and anything in sources.list.d?


I think when a user is reviewing it would be useful if they can view their remaining review count in review-bar, such as 14 of 20.    Can this be implemented?

Once you already have a gold badge for a queue, the number of total reviews is hard to keep track of where you're at. I'd like to see how many reviews I've done so far today in the queue. For example, if I've already done 16 out of my 20 possible, show that.   I don't care whether it's a bar graph, just text, tally marks, etc.  It'd be nice to show this info, so it can maybe motivate people to complete all their reviews for the day, and give the user a status of where they are at for the day. I suggest implementing this in all queues, for all users, whether gold badge or not in the queue.


I am trying to calculate the dimensions of an object in an image. This is a sample image I took to get height of the brown box.  I have this white box which measures 16cm and I would like to know the height of the brown box (in meter). This using only the focal length and the size of the camera sensor of my phone. Focal Length: 3.99mm Focal Length In 35mm Size: 29 mm Sensor size: 4.8mm * 3.5mm Height of the image: 4032px Size of the brown box in pixels: 1459px Distance between the sensor and the box: 1.8m  I did this:   So I found boxheight = 0.78m In reality, this brown box measures 0.75m, so I want to know if it’s possible to obtain a more accurate result by using the fact that I know the exact size of the white box next to it. Does anyone know ? Thank you

How does the size/length of an object vary with distance?   Is it a logarithmic relationship? exponential? linear?   I plotted a curve of the size/length of an object for different distances from the camera, and the curve looked exponential/logarithmic. I was trying to understand the reasoning behind that.


When I am running sudo apt update, it gives me this error:  [sudo] password for devuser: Hit:1 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic InRelease Hit:2 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-updates InRelease Hit:3 http://us-east-1.ec2.archive.ubuntu.com/ubuntu bionic-backports InRelease Hit:4 http://security.ubuntu.com/ubuntu bionic-security InRelease Traceback (most recent call last):   File "/usr/lib/cnf-update-db", line 8, in <module>     from CommandNotFound.db.creator import DbCreator   File "/usr/lib/python3/dist-packages/CommandNotFound/db/creator.py", line 11, in <module>     import apt_pkg ModuleNotFoundError: No module named 'apt_pkg' Error in sys.excepthook: Traceback (most recent call last):   File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook     from apport.fileutils import likely_packaged, get_recent_crashes   File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in <module>     from apport.report import Report   File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in <module>     import apport.fileutils   File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in <module>     from apport.packaging_impl import impl as packaging   File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 24, in <module>     import apt   File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in <module>     import apt_pkg ModuleNotFoundError: No module named 'apt_pkg'  Original exception was: Traceback (most recent call last):   File "/usr/lib/cnf-update-db", line 8, in <module>     from CommandNotFound.db.creator import DbCreator   File "/usr/lib/python3/dist-packages/CommandNotFound/db/creator.py", line 11, in <module>     import apt_pkg ModuleNotFoundError: No module named 'apt_pkg' Reading package lists... Done E: Problem executing scripts APT::Update::Post-Invoke-Success 'if /usr/bin/test -w /var/lib/command-not-found/ -a -e /usr/lib/cnf-update-db; then /usr/lib/cnf-update-db > /dev/null; fi' E: Sub-process returned an error code   How to fix this?

I run below command on ubuntu 16.4 :  sudo add-apt-repository ppa:noobslab/apps  of below question:    and get below error:  Traceback (most recent call last):   File "/usr/bin/add-apt-repository", line 11, in <module>     from softwareproperties.SoftwareProperties import SoftwareProperties, shortcut_handler   File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 27, in <module>     import apt_pkg ModuleNotFoundError: No module named 'apt_pkg' Error in sys.excepthook: Traceback (most recent call last):   File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook     from apport.fileutils import likely_packaged, get_recent_crashes   File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in <module>     from apport.report import Report   File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in <module>     import apport.fileutils   File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in <module>     from apport.packaging_impl import impl as packaging   File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 23, in <module>     import apt   File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in <module>     import apt_pkg ModuleNotFoundError: No module named 'apt_pkg'  Original exception was: Traceback (most recent call last):   File "/usr/bin/add-apt-repository", line 11, in <module>     from softwareproperties.SoftwareProperties import SoftwareProperties, shortcut_handler   File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 27, in <module>     import apt_pkg ModuleNotFoundError: No module named 'apt_pkg'   Thanks for help


I just upgraded to VS 2015 and its complaining about me using the capital String  version of string, saying it can be simplified.  I tried googling for IDE0001 and clicking the link but neither gave me any good info on why this is a thing. CS0168 appears to be unrelated as well ()  Is there any reason to use the lower case version over the upper case version?

Example (note the case):  string s = "Hello world!"; String s = "Hello world!";   What are the guidelines for the use of each? And what are the differences?


Ahhh yes this problem again...  So I have a rather complex set of compositing layers to set up, some nodes masking areas and others just splitting up the scene components. Now I've run into this issue many times while compositing with trees or vegetation, but the only method that I've found to work doesn't allow for a lot of flexibility.  To composite layers I find I need to use layer masking to allow for objects to appear in front of each other, but when using mask layers on objects with tons of transparency, the camera doesn't register the z depth correctly and just renders the entire mesh. This blocks other objects when combining layers.    Is there a better way to combine layers with lots of transparency? I cannot put the trees on the same layer as other objects because they all use different compositing effects.  Compositor if needed:   Cheers,

I have multiple scenes each with different objects. I want to combine all these scenes in the compositor but when they render, all the objects from each scene overlap each other and are all transparent, so I can see all the objects when some should be hidden behind others.   To join my scenes I'm using a mix node with add.


The problem: How many minimum number of integers must be selected from the set $\{1, 2, 3, 4,\dots,99, 100\}$ to ensure that there are at least two integers in the selection such that one divides the other. My sloppy thinking: If we select $25$ primes, none of them of course will divide the other. If, however, we choose a $26^{th}$ number, it must divide some or the other. So the answer is 26. The actual answer, however was 51. Hints?

Given a set of $n+1$ numbers out of the first $2n$ natural numbers, $\{1,2,\ldots,2n\}$, prove that there are two numbers in the set, one of which divides the other.  I can't tell if I'm reducing the problem in the right way.  Would it be something like:  Induction Hypothesis: A set of $n+1$ numbers from the first $2n$ natural numbers contains two numbers, one of which evenly divides the other.  Base Case: $n=1$, $\{1,2\}$, 2 is divisible by 1.  Consider a set of $n+2$ numbers, $A$, from the first $2n+2$ natural numbers. There are three cases:   Each number in $A$ is less than or equal to $2n$.  The proof follows from the induction hypothesis. One number in $A$ is greater than $2n$.  The remaining set of $n+1$ numbers must each be less than or equal to $2n$.  The proof follows from the induction hypothesis. $A$ contains both $2n+1$ and $2n+2$. I'm not sure how to solve this case.   I'm working through Udi Manber's Introduction To Algorithms: A Creative Approach for personal development, so in keeping with the spirit of the book, I'm trying to use induction.  Without induction, the question is identical to


I was trying to loop over a list in python using the indices but it drops error. Can you guys help me out with this? What could be the syntax that could fix this ?   abs = [10,20,40]   for i in abs:      new_abs = abs[i]+ abs[i+1]     print(new_abs)   So, i have managed to use hard code for the temporary use.   abs = [10,20,40]  new_abs = [ abs[0], abs[0]+ abs[1] , abs[1]+abs[2] ]  print(new_abs)   Can you please, let me know the proper syntax to loop over this index numbers?

How do I access the index in a for loop like the following?  ints = [8, 23, 45, 12, 78] for i in ints:     print('item #{} = {}'.format(???, i))   I want to get this output:  item #1 = 8 item #2 = 23 item #3 = 45 item #4 = 12 item #5 = 78   When I loop through it using a for loop, how do I access the loop index, from 1 to 5 in this case?


Why do we use have instead of has with doesn't like in the following sentence:  He doesn't have(not has) to go there.  Please explain the grammatical reason behind it.  Thanks

In regard to this , my question is similar but that answer is not clear. I want to know why we use base form of verb, e.g. 'go' to form the past tense instead of past form such as 'went'?     Question: Did you go to a bank?  (Why we use 'go' here, rather than 'went'?)   Answer: I went to a bank.   Am I confusing verb forms with tenses? Please note that I'm not a native speaker so some clarification or reference on this would be helpful.


In latex, I am writing a pseudocode where I want to have output (of input and output) in the following fashion:   This is my code:  \documentclass[sigconf]{acmart} \usepackage{amsmath}  \usepackage{algorithm} \usepackage{algpseudocode} \begin{document} \begin{algorithm}\label{algo:ProclivityProp2} \caption{Graph} \begin{algorithmic}     \State Input T matrix of measurements      \State Output  $\hat X$ \quad matrix of graph signals\\                    $\hat W$ \quad matrix of outliers\\ \end{algorithmic} \end{algorithm} \end{document}   And this is my output:  When I use \Input{..} or \Output{..} in my code, I get the following error:   ! Undefined control sequence.<recently read> \Input \Input   ! Undefined control sequence \Output   How can I get the desired output (the first picture)?

I am using ACM format for writing a paper. I use the following algorithm sample that is taken from this form. I want to add input and output before MyProcedure. I tried many ways but all fails. Can someone guide me? Thank you  \usepackage{algorithm} \usepackage[noend]{algpseudocode}     \begin{algorithm}     \caption{My algorithm}\label{euclid}     \begin{algorithmic}[1]      % Input:      % Output:      \Procedure{MyProcedure}{}     \State $\textit{stringlen} \gets \text{length of }\textit{string}$     \State $i \gets \textit{patlen}$     \BState \emph{top}:     \If {$i > \textit{stringlen}$} \Return false     \EndIf     \State $j \gets \textit{patlen}$     \BState \emph{loop}:     \If {$\textit{string}(i) = \textit{path}(j)$}     \State $j \gets j-1$.     \State $i \gets i-1$.     \State \textbf{goto} \emph{loop}.     \State \textbf{close};     \EndIf     \State $i \gets i+\max(\textit{delta}_1(\textit{string}(i)),\textit{delta}_2(j))$.     \State \textbf{goto} \emph{top}.     \EndProcedure     \end{algorithmic}     \end{algorithm}


We can easily recognize bipartite graphs, but I surprisingly couldn't find anything on the recognition complexity of 3-uniform tripartite hypergraphs, though I'm sure this has been studied. It's also in P, right? What about larger $k$?

I am interested in the following problem: Given a set X and subsets X_1, ..., X_n of X, find a coloring of the elements of X with k colors such that the elements in each X_i are all differently colored. More specifically, I am looking at the case where all X_i are of size k. Is this known in the literature under some name?  I am looking for characterizations of colorable instances and results on complexity (P vs. NP-hard). For example, for k=2, colorable instances correspond to bipartite graphs, and thus the problem can be solved in polynomial time.


Currently, bounties are used to obtain a proper answer. But only, at least, 2 days after being asked. It's a lot of time if you're a professional and you need that simple thing solved to keep going!  "There are reasons for that delay, you know?"  Of course I know, and I think the delay is set mostly because if everyone could set a bounty right from the beginning, people would start to look only on those questions.  But still, this is a feature that we have to consider. There are moments that we can't really wait and we know that no one will probably answer our question otherwise.  What if...  We are able to set special bounties after 1 hour, paying a fee of 50% to set it?  For example, you want to set a 100 reputation bounty before 2 days past. You will have to pay 150 rep, but the award will still worth 100.   This way, it will reduce the number of "emergency bounties", and consequently, the number of users that won't answer to normal questions to wait for the bounty.

A question is eligible for bounty 2 days after creation. Probably because  New questions don't need to be bountied, since they already show up in the New tab and the Active tab and so on (and thus get attention anyways)  . But reality is different In the first 5 minutes after asking you get the majority of views. That has probably *. The view counts drop due to the heavy amount of new questions - thousands every day! If you don't get an answer in the first minutes then you have to wait 2 days to put a bounty on it. Please either remove the bounty delay or reduce it dramatically to an hour or so. * Of course that query does not factor in that question lying around for years have more views than new ones. But the tendency is given IMO.


I recently came across  post on 4chan, and I really want to find out where the original poster went wrong. Unfortunately, I myself have barely done any real analysis and even though I know it is very wrong I can't find exactly why. The basic argument is this: let $q_\mathbb N(x)$ be the number of elements in $\mathbb N$ with $x$ digits let $q_\mathbb R(x)$ be the number of elements in $S = \{0 < x < 1 | x \in \mathbb R\}$ with $x$ digits (e.g. $q_\mathbb R(3) = 10 \times 10 \times 9$ since it can be formatted as $0.(0-9)(0-9)(1-9)$) So the number of elements in $\mathbb N$ must be $\sum_{n=1}^\infty q_\mathbb N(n) = 10 + 9 \times 10^1 + 9 \times 10^2 + \dotsb$ And the number of elements in $S$ must be $\sum_{n=1}^\infty q_\mathbb R(n) = 10 + 9 \times 10^1 + 9 \times 10^2 + \dotsb$ Thus there are the same number of elements in $\mathbb N$ as there are in $S$.

I was just thinking about this recently, and I thought of a possible bijection between the natural numbers and the real numbers.  First, take the numbers between zero and one, exclusive.  The following sequence of real numbers is suggested so that we have bijection.    0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.01, 0.02, ... , 0.09, 0.10, 0.11, ... , 0.99, 0.001, 0.002, ... , 0.999, 0.0001, etc.  Obviously, this includes repeats, but this set is countable.  Therefore, the set of all numbers between zero and one is a subset of the above countable set, and is thus countable.  Then we simply extend this to all real numbers and all the whole numbers themselves, and since the real numbers, as demonstrated above, between any two whole numbers is countable, the real numbers are the union of countably many countable sets, and thus the real numbers are countable.    Please help me with this.  I understand the diagonalization argument by Cantor, but I am curious specifically about this proof which I thought of and its strengths and flaws.  Thanks.


String name; String count; Scanner keyboardn = new Scanner(System.in); Scanner keyboard = new Scanner(System.in); System.out.println("Enter Full Product Name"); name = keyboard.nextLine(); count = keyboard.nextLine(); String [] p = name.split(" "); for(String s : p) {      if (count == "1"){  System.out.println(p[0]);}     if (count == "2"){  System.out.println(p[1]);}     if (count == "3"){System.out.println(p[1]);}     if (count == "4"){System.out.println(p[1]);}     if (count == "5"){System.out.println(p[1]);}     if (count == "6"){System.out.println(p[1]);}     if (count == "7"){System.out.println(p[1]);}     if (count == "8"){System.out.println(p[1]);}     if (count == "9"){System.out.println(p[1]);}     if (count == "10"){System.out.println(p[0]+", "+p[1]+", "+ p[2]+", "+p[3]+", "+p[4]+", "+p[5]+", "+p[6]+", "+p[7]+", "+p[8]+", "                 + ""+p[9]+", "+p[1]+p[2]+", "+p[1]+p[2]+p[4]+", "+p[1]+p[2]+p[4]+p[5]+", "  );     } }   the program is not out puting any response using if statments i thought would work the best let me know if there are any other sugestions

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


How to handle with multi buttons?  I´m using this code to change SoundOff to soundOff ON click  I dont now how to fix the error  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);       setContentView(R.layout.gameover);      //setting the orientation to landscape     setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);        ImageView medaille = (ImageView) findViewById(R.id.medaille);     //adding a click listener      //Define Logout     ImageButton LogOut = (ImageButton) findViewById(R.id.imageButton8);      //Define SoundOn      ImageButton SoundOn = (ImageButton) findViewById(R.id.imageButton9);      //Define SoundOff      ImageButton SoundOff = (ImageButton) findViewById(R.id.imageButton10);      //getting the button     ImageButton ButtonOk = (ImageButton) findViewById(R.id.imageButton11);      LogOut.setOnClickListener(this);     SoundOff.setOnClickListener(this);     SoundOn.setOnClickListener(this);     ButtonOk.setOnClickListener(this);      // Version      //define     TextView txtView = (TextView) findViewById(R.id.tv_current_score);      TextView txtsView = (TextView) findViewById(R.id.tv_current_score_value);     txtsView.setText(String.valueOf(GameView.score));      //Value     TextView myText = (TextView) findViewById(R.id.tv_best_score_value);     myText.setText(String.valueOf(GameView.Highscorer) );      TextView txtViews = (TextView) findViewById(R.id.tv_best_score);   }    @Override       public void onClick (View v){      //Define Logout     ImageButton LogOut = (ImageButton) findViewById(R.id.imageButton8);      //Define SoundOn      ImageButton SoundOn = (ImageButton) findViewById(R.id.imageButton9);      //Define SoundOff      ImageButton SoundOff = (ImageButton) findViewById(R.id.imageButton10);      //getting the button     ImageButton ButtonOk = (ImageButton) findViewById(R.id.imageButton11);     switch (v.getId()) {              case R.id.imageButton11:                 //starting game activity                 startActivity(new Intent(this, GameView.class));                 break;              case R.id.imageButton4:                 //Logout                 startActivity(new Intent(this, GameLogout.class));                 // do your code                 break;             case R.id.imageButton8:                 startActivity(new Intent(this, GameLogout.class));                 break;             case R.id.imageButton9:                 play = false;                 SoundOn.setVisibility(View.GONE);//set visibility to false on create                 SoundOff.setVisibility(View.VISIBLE);                 break;             case R.id.imageButton10:                 play = true;                 SoundOn.setVisibility(View.VISIBLE);//set visibility to false on create                 SoundOff.setVisibility(View.GONE);            }      }   I´m getting an error in NullPointerException in the "SoundOn.setVisibility(View.GONE);//set visibility to false on create"

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?


Why do we sometimes use "there is" for a plural form in our sentences? Example: "There is some cars". Is this true?

I was just wondering how can you use "there is" followed by a word that is in plural, e.g  "There's cupcakes in the fridge"  and  "There is a couple of things we can do --"   Is it just slang?


I could not find any references related to what does ${#} actually means in shell scripting, My rough guess is that it means the last variable passed to an invocation, but not completely sure.

What does $# mean in shell?  I have code such as  if [ $# -eq 0 ] then   I want to understand what $# means, but Google search is very bad for searching these kinds of things.


I was wondering if there was an extension of Euler's Identity to quaternions. Now, in two dimensions, there is only one direction of rotation. In three dimensions, there are two,"axes", of rotation. Therefore, the formula that I would like needs three different values of theta for rotation. Is there any such formula? Notice: The other formulas that were provided on this site are based on one angle of theta and a quaternion rotation on the angle theta. However, since four-dimensional space has three axes of rotation, the formula provided should have three values of theta.

Euler's identity is $e^{i \pi} + 1 = 0$, a special case of the Euler's formula $e^{i\theta} = \cos\theta + i\sin\theta$, where $\theta = \pi$ (half-turn of the unit circle).  It is commonly described as "beautiful" because it is simple and includes a bunch of fundamental mathematical constants and operators, including the complex numbers.    Is there a corresponding Euler's identity for ?  Speculation:    proposes a different fundamental circle constant, $\tau = 2 \pi$, and a corresponding alternate Euler identity, based on a complete turn, the special case of $\theta = \tau$:   $e^{i\tau} = 1$  If both identities are extended to quaternions, is one any simpler or more "beautiful" than the other?


I have an iPhone 4s with an iOS 7.1. I wish to update my phone to iOS 8 or 8.1 because most apps only support 8 or higher. I do not however want to update to the latest version supported on the 4s (iOS 9.3.5). Is there a way I could update by phone to iOS 8 and not iOS 9?

I'm trying to downgrade my iPhone from the current iOS to an older one, as per .  But every time I try, I always receive this error:     The iPhone could not be restored. This device isn't eligible for the requested build.     I have tried many times with and without DFU mode. Any ideas regarding this?


Why shouldn't I use GROUP BY in place of DISTINCT when writing a query that does not contain an aggregate function?  What is the best practice?

If I have a table  CREATE TABLE users (   id int(10) unsigned NOT NULL auto_increment,   name varchar(255) NOT NULL,   profession varchar(255) NOT NULL,   employer varchar(255) NOT NULL,   PRIMARY KEY  (id) )   and I want to get all unique values of profession field, what would be faster (or recommended):  SELECT DISTINCT u.profession FROM users u   or  SELECT u.profession FROM users u GROUP BY u.profession   ?


Other than downloading the video, is there any way to re-enable YouTube's speed-up controls, which allowed playback w/ 1.5x, 2x, 4x the original speed?  (This was the only way I could watch lectures and vlogs; they are essential for those videos.)

Is there a way to speed up YouTube playback?


As per the title, would these magnets    be enough to damage a portable hard drive such as this Seagate GoFlex     if left next to each other for longer than, say, 20 minutes?  Thankfully, this is all hypothetical at this point as I have kept them apart to date and my question comes to mind if the two fell on top of one another whilst in a backpack or bag.

I was wondering what would be the safest magnetic field for a hard drive so that the data inside it is safe and not wiped off?  For example I have a 2.1 home theatre system and when I take my android phone near it to check the magnetic field range it gives me a reading of 1000 micro Tesla. Would that be considered safe for a nearby hard disk?


When pledging his allegiance to Darth Sidious, Anakin states: "I will do whatever you ask... just help me save Padme's life, I can't live without her."  However, after learning of Padme's death, Anakin can clearly 'live without her'. The whole reason he joined the Dark side in the first place was because he believe the Jedi were too weak to save her, but as the Dark side has also failed, surely he could decide to turn back to the light side?

In the prequels, the primary reason Anakin was willing to become  is because he wanted to save Padmé;     ANAKIN: I will do whatever you ask.       PALPATINE: Good.       ANAKIN: Just help me save Padme's life. I can't live without her. If she dies, I don't know what I will do.      PALPATINE: To cheat death is a power only one has achieved, but if we work together, I know we can discover the secret.       ANAKIN kneels before PALPATINE.       ANAKIN: I pledge myself to your teachings. To the ways of the Sith.   Given that he didn't manage to save her, why did he still become a Sith?


Problem. Let $1\le p<\infty$ and $n \ge 1$ and let $W^n_p[0,1]=$ the functions $f:[0,1]\to \Bbb{C}$ such that $f$ has $n-1$ continuous derivatives, $f^{(n-1)}$ is absolutely continuous, and $f^{(n)} \in L^p[0,1]$. For $f$ in $W^n_p[0,1]$, define $$||f||:=\sum_{k=0}^n\left[\int_0^1|f^{(k)}(x)|^p ~\mathrm{d}x\right]^\frac{1}{p}$$ Then $W^n_p[0,1]$ is a Banach space.  If we take a Cauchy sequence $(f_j)_j$ in $W^n_p[0,1]$, then it follows that $(f_j^{(k)})_j$ is Cauchy in $L^p[0,1]$ for all $k = 0, 1, \dots, n$. Hence there are $g_{k} \in L^p[0,1]$ such that $(f_j^{(k)})\to g_k$ for $k = 0, 1, \dots, n$. From this how to prove that $g_k=g_0^{(k)}$ for all $k = 1, \dots, n$? Thanks. EDIT I tried to proceed as follows: $f_j \to g_0$ in $L^p$ $\implies \text{for some subsequence }f_{j_l}\to g_0$ a.e. on $[0,1]$. Then we have $$g_0(x)= \lim f_{j_l}(x)= \lim \int_0^x f_{j_l}^{'}=\int_0^x\lim f_{j_l}^{'}=\int_0^x g_1$$ for a.e $x$ in $[0, 1]$. This implies $g_0'(x) = g_1(x)$ a.e. $x$ . Now similarly we can prove others. Then since $f_j^{(n-1)}$ was absolutely continuous functions with $L^p$ derivatives we can use this to prove that $g_{n-1}(=g_0^{(n-1)})$ is also absolutely continuous with $L^p$ derivative. And this shows that $g_0 \in W^n_p[0,1]$. Is there any mistake?

Show that Sobolev space is complete. I am trying  Than $L^p(\Omega)$ is complete then If $f_n \in L^p(\Omega)$ then $f_n \to f \in L^p(\Omega)$. But rest show that $D^{\alpha}f \in L^p(\Omega)$. How I will be able to show this?


Is there a free/open source alternative to teamviewer that will allow me to help a friend running Ubuntu 14.04 with the default unity desktop?  Some years ago Ubuntu had a way to share screen/mouse built in (I think it was called "share desktop") but I can't find it in 14.04.  Notes:   I want a shared desktop session not a separate one. I'm already able to VNC to a separate session but I need to see and click what my friend sees. I don't want to change my friends Unity desktop. He has trouble adapting to such changes.

I'm looking for an application similar to teamviewer to install on ubuntu 10.10. I know that the teamviewer's staff has released a version for ubuntu, but I'd like to use something completely open. Someone can help me?


Show that $a_n=\sin(n)$ does not converge     My idea:  Take two subsequences: $a_{n_k}=\sin(\frac {\pi k} 2)$ , $a_{n_l}=\sin(\frac {2\pi l} 3)$  So: $\forall n$ : $\lim_{n\to\infty} a_{n_k}=1$, $\lim_{n\to\infty} a_{n_l}=-1$  So two inifinite subsequence converge to different limits thus the sequence $a_n$ doesn't converge.   Is that correct ?  Edit:   The contrapositive of the defintion of a limit of a sequence:   $\exists\epsilon>0 : \forall n\in N : \exists n>N \Rightarrow |x_n-L|>\epsilon$  Take $\epsilon =1$ and we know that $\sin(n)$ is bounded so lets take it's supermum: 1  $|1-1|>\epsilon=1\Rightarrow 0>1 \Rightarrow$ Contradiction.

Using only the delta definition of a limit, how can we prove that the sequence $\{a_n\}$, where $a_n = \sin n$, as $n$ tends to infinity does not have a limit?  Thanks!


recently I had reset my ubuntu password using the information provided here   By this am changed successfully, but here my question is how can we get security with this. any one can able to reset our password without our knowledge

How is the ability of a person who gained physical access to your computer to get root with those steps in any way secure?   When grub2 menu opens press  e  to edit the Linux start options Change:   "linux   /vmlinuz-2.6.35-23-generic root=UUID=e7f1e48d-0015-485f-be7d-836217a31312 ro   quiet splash"    to:  "linux   /vmlinuz-2.6.35-23-generic root=UUID=e7f1e48d-0015-485f-be7d-836217a31312 ro init=/bin/bash"  Now you have root access just do:   mount -o remount,rw / passwd user mount -o remount,ro /  sync  reboot the computer and you win.   My question is, how is being able to break into any Linux machine through grub2 secure? I don't understand that fact about Linux, thank you for your answers.


Scenario is :   I Have a MainActivity(MainActivity.java) with pager making Fragment(MyFragment.java) in it.   I have one more activity called Main2Activity(Main2activity.java).  I want to send Data from Main2Activity to MyFragment.  Main2Activity.java:    public class Main2Activity extends AppCompatActivity{    private String myString = "hello";    @Override    protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main2);              Bundle bundle = new Bundle();             bundle.putString("path1", "Hey Brother");              MyFragment frgmentObj = new MyFragment ();             frgmentObj.setArguments(bundle);     }   MyFragment.java :     public class MyFragment extends android.support.v4.app.Fragment{    @Override   public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {  String brother = getArguments().getString("path1");   // Here showing NPE   return view; } }   But its giving me Null pointer exception       java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference   please help me out package is same Thanks

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?


Does there exists a function which maps Cauchy sequence to Cauchy sequence but it isn't uniformly continuous?  we know uniformorly continuous function maps cauchy sequence to cauchy sequence.But  my book doesn't say anything about converse of i think its false. but didn't find a counter example yet . please help!

Let $f$ be a continuous function. If $f$ is uniformly continuous then it maps cauhy sequence into cauchy sequence. Is the converse true? That is if $f$ maps cauchy into cauchy gives the uniform continuity of $f$. I think it's no. Can suggest a counter example


Let $f, g$ be continuous from $\mathbb R$ to $\mathbb R$, and suppose that $f(r) = g(r)$ for all rational numbers $r$. Is it true that $f(x) = g(x)$ for all $x \in \mathbb R$?

$f,g: \mathbb{R} \to \mathbb{R}$  I'd like to see a sketch for this proof.  [sorry for posting errors, I am on a cell phone]


I am reading a book, written in Latex, and I saw a button, on which I can click and immediately I have a Wolfram notebook opened: I want to do such cool buttons too, can anyone tell me, how to add it?

Several times now I have inadvertently lost the .tex file that generated a PDF file with pdflatex. Given what I know of the internal structure of PDF files, it should be possible to embed a text file containing the original LaTeX file into the PDF file so that it can be extracted later.   I am aware of no technology for doing this, but perhaps you are. Does anybody have something like this?


On a sheet of paper it is drawn a point $A$ and 2 lines $L_1$ and $L_2$ which intersect outside the sheet in a point B. How one can draw a line $AB$ using only a ruler?

Its very common in illustration to want to draw a line towards a vanishing point that is off of the page.   The specific problem is this: lets say we draw two line segments on a piece of paper lying on a flat surface. The line segments are drawn such that, if extended beyond the edge of the page, they intersect at a point $A$. Next, we draw a point $B$ anywhere on the page.   Without actually extending the two line segments to find $A$, is there a way to draw a line segment such that, if extended to a line, would intersect both $A$ and $B$ using only a straight edge and compass construction?   Looking for an answer with the fewest number of steps.


I'm setting up a very simple online shop for a charity. They'll use Paypal WPS and don't want to collect customer's billing address as those will be entered in Paypal anyway. Is there a way to remove the billing address from Drupal Commerce.  I'm only using PayPal, so the aforementioned answer doesn't apply.

Till now, I have been using only PayPal checkout on my Commerce site, and I have configured the checkout flow so all of the customer's information is collected over on PayPal's site.  However, I am now trying to add Stripe as an alternate payment method.  I need to collect the customer's billing info on my site when using Stripe, so I need to add Billing information to the checkout pane.  Goal   Show Billing information if the customer selects Stripe as the payment method.  If the customer selects PayPal, do not show Billing information.   I looked through the various commerce events and actions available in the Rules module, but I couldn't find anything that is helpful for this case.


It's possible to perform a login ( with lightdm or anything else ) and enter directly in command line mode without enabling any GUI for the user ?

Is it possible to disable X at boot time? I'm setting up a server so it would be nice if it wouldn't load the graphical interface every time I boot.


I am travelling from India and have 7.5 hours of layover at Heathrow airport for my connecting flight to Canada. I am arriving on terminal 4 and connecting flight departs from terminal 2. In the meantime of my layover a few of my friends wants to visit me at the airport so do I need DATV to meet them personally? Or is it possible to meet friends at the airport without any transit visa as I am not going out of the airport premises. Do I have to collect my bags and recheck-in if I have DATV? Is there any other possible way to spend the layover time with my friends at the airport?

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.


After you've made the background transparent, color selected the background and inverted the selection to outline all the character sprites:  Is there a shortcut or some quicker method/program/tool to turn each sprite into an individual selection and then turn each selection into an individual layer? If not with GIMP, are there any other free programs that will allow you to do this?

I am using Inkscape and Gimp to create assets for a word game and am looking for an advice from more experienced users of these great tools.  In Inkscape I have created  with 26 letters and their values:    The stripe is comfortable to edit - I have enabled grid snapping there and also I can always revisit the SVG file and change font sizes or letter values.  Then I have exported the SVG file as a whole page to PNG files in different resolutions:    Unfortunately, loading  does not work with Android (because of OpenGL width limitation for textures - 2048 pixels on many devices).  So I have to split the SVG file or the resulting PNG files in square images of 240 x 240 pixels for each letter (Android could process them without problems).  My question is if anyone knows a good way to perform such a split in Inkscape (that would be best) or in Gimp?  In Export Bitmap dialog of Inkscape I see a batch-related checkbox... Could it be used for my purposes?


I have tried installing Ubuntu on my computer. I used Rufus to burn the .iso and selected the boot device on bios. The problem is the dual boot option is not available. My PC is Windows 7 64-bit, 4 GB RAM; Dual core Pentium processor 2.5 GHz.

This question is asked often in Ask Ubuntu, sometimes with few hints about the situation.   Please provide a list of possible reasons to help troubleshoot the problem.


I'm very new to Java and regex and has no experience with android development (but I've been tasked to fix a bug). My question breaks down into two parts.  I have an error that shows:  Fatal Exception: java.lang.IllegalStateException: Fatal Exception thrown on Scheduler. ... ... ...  Caused by java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.matches(java.lang.String)' on a null object reference        at utils.DataParsingUtils.isInteger + 195(DataParsingUtils.java:195)        at services.FCMService.createChatNotification + 255(FCMService.java:255)   Doing some tracing, I believe the error originates from the file /utils/DataParsingUtils and from the function isInteger, which is shown below.  public static boolean isInteger(String s) {     return s.matches("^-?\\d+$"); }   Based on the error, I think it has to do with a null value being returned. In this case from the isInteger function. This leads me to 2 questions.   What exactly is the regex doing? My research tells me:   a) " = matches the beginning of the line b) - = indicates a range c) ? = does not occur or occurs once d) \\d = matches the digits e) + = matches one or more of the previous thing. (In this case the digits) f) $ = matches end of the line.  However I'm having a hard time putting everything together. Does it only want matches that start or end with digits but where do - and ? come in?    Can this regex return a null? From different sources I see   Source A:  s.matches("regex") evaluates if "regex" matches s. Returns only true if the WHOLE string can be matched.   Source B:  If the regular expression matches the whole text, then the matches() method returns true. If not, the matches() method returns false.  You cannot use the matches() method to search for multiple occurrences of a regular expression in a text. For that, you need to use the find(), start() and end() methods.   It doesn't explicitly state that under no condition can a null be returned but my understanding is that it can only return True or False? If that is the case, why does the NullPointerException point to the isInteger function?  Note: I've checked line 255 within the function createChatNotification and it's a call to the function isInteger.  private void createChatNotification(String argA, final String argB, final String argC) {          if (DataParsingUtils.isInteger(argA)) {

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?


There it said that I should edit the environmental variable in front of the Ssteam desktop application How?  I really want to be able to just click on the icon on my desktop as opposed to opening terminal every time and typing a long command. Help? Please?  Also, I don't know anything about coding/Linux.

After a botched upgrade from Ubuntu 14.04 to Ubuntu 16.04 I had to wipe my system and start all over. This time I decided to go with a much less CPU intensive desktop environment and installed Lubuntu 16.04-1.  My problem: when I run Steam from the menu shortcut it acts like it is doing nothing. However it does show up in the task manager. If I just type steam in the terminal I get the following.  michael@michael-HP-Pavilion-dm1-Notebook-PC:~$ steam Running Steam on ubuntu 16.04 64-bit STEAM_RUNTIME is enabled automatically grep: symbol lookup error: grep: undefined symbol: pcre_jit_stack_alloc grep: symbol lookup error: grep: undefined symbol: pcre_jit_stack_alloc /bin/bash: /home/michael/.local/share/Steam/ubuntu12_32/steam-runtime/amd64/lib/x86_64-linux-gnu/libtinfo.so.5: no version information available (required by /bin/bash) grep: symbol lookup error: grep: undefined symbol: pcre_jit_stack_alloc awk: /home/michael/.local/share/Steam/ubuntu12_32/steam-runtime/amd64/lib/x86_64-linux-gnu/libtinfo.so.5: no version information available (required by /lib/x86_64-linux-gnu/libreadline.so.6) Installing breakpad exception handler for appid(steam)/version(1468023329) libGL error: unable to load driver: r600_dri.so libGL error: driver pointer missing libGL error: failed to load driver: r600 libGL error: unable to load driver: swrast_dri.so libGL error: failed to load driver: swrast   Then nothing happens including steam doesn't show up in the task manager. Now I did find the command.  LD_PRELOAD='/usr/$LIB/libstdc++.so.6' DISPLAY=:0 steam   This does run Steam but it is not a real solution in my eyes. How can I fix it?


If $f$ is injective and $g$ is not injective, $g\circ f$ is not injective?  If $f$ is surjective and $g$ is not surjective, $g\circ f$ is not surjective?

The Problem:  Let $X, Y, Z$ be sets and $f: X \to Y, g:Y \to Z$ be functions.  (a) Show that if $g \circ f$ is injective, then so is $f$.  (b) If $g \circ f$ is surjective, must $g$ be surjective?  Where I Am:  So, I really have trouble with these, for some reason. I can draw pictures and make sense of the problems, but writing down proofs is very difficult for me.   Basically, for (a), I ended up with some complicated statement involving an implication implying another implication and then tried to derive a contradiction. It just got so convoluted that I couldn't make sense of it anymore, and I know there's a quick, elegant way to show it.  For (b), I know that $g$ need not be surjective. Once again, though, proving it directly from definitions has given me a bit of a headache.  Any help here would be appreciated. Thanks in advance.  The Proofs!  Ok, I did it. Thanks for the help, everyone! Let me know if there's anything wrong with these proofs, or if they could bet any better.  (a) Suppose $f$ is not injective. Then $$ f(x_1)=f(x_2) \implies x_1 \ne x_2 \text{        }(*).$$ Let $f(x_1)=y_0=f(x_2)$ and let $g(y_0)=z_0$. Then $$ (g \circ f)(x_1) = (g \circ f)(x_2) = g(y_0) = z_0. $$ Since $g \circ f$ is injective, $$ (g \circ f)(x_1) = (g \circ f_2) \implies x_1 = x_2. $$ However, this contradicts $(*)$. Therefore, $f$ must be injective.  (b) Suppose $g$ is not surjective. Then  $$ \forall y \in Y, \exists z \in Z \text{ such that } g(y) \ne z \text{         }(**).$$  Since, $g \circ f$ is surjective,  $$ \forall z \in Z, \exists x \in X \text{ such that } g(f(x)) = z \text{       } (***). $$  Let $f(x) = y$. Then,  $$ g(f(x)) = g(y) = z. $$  Because of $(***)$, this is true for all $z \in Z$, which contradicts $(**)$. Therefore, $g$ must be surjective.


Let $n$ be a composite integer. Show that there exists a prime $p$ dividing $n$, with $p\leq n^{1/2}$.  $n$ is a composite integer so $n= ab$ where $a$ and $b$ are larger than $1$, let $p$ be a prime, suppose $p^2 \leq a^2 \leq ab = n$, because $p \ | \ a$ and $a \ | \ n$ then $p \ | \ n$. Hence, $p\leq n^{1/2}$. Am I right about this?

Prove that if a number $n > 1$ is not prime, then it has a prime factor  $\le \sqrt{n}$.  My answer is that this is not always true, because you can pick a non-prime number that is greater than $1$ and its factor is equal to its square root.


Similar to the question (and MWE) asked in the link below, I would like to organise my navigation bullets horizontally per section. However, in addition, I would like to group the bullet points by subsection.   hence, instead of:  Section 1  ooooooooooo  I would like to have  Section 1  ooo ooo ooo oo  Where the dots are grouped by subsection. I am using the Singapore theme.

I'm using the beamer miniframes theme (with subsection=false) and the compress option. Currently the navigation shows the dots for each subsection side-by-side. I would prefer if there would be a horizontal space (e.g. with the width of a dot) between the dots of each subsection. Is this possible? Right now it looks like:  Section 1 oooooo  And I would prefer it to look like:  Section 1 ooo ooo  MWE: \documentclass[compress]{beamer}   \useoutertheme[subsection=false]{miniframes}   \begin{document}   \section{Sec 1}   \subsection{}   \begin{frame}[t]     hi   \end{frame} \subsection{}   \begin{frame}[t]     hi   \end{frame} \end{document}`


I have Indian passport and currently visiting USA with my wife.  While returning to India in January 2020, we have 18 hrs layover at Narita International (NRT). From USA we will be travelling by American Airlines and from Japan by Japan airlines. Do we need transit visa for 18 hrs to stay in a hotel at NRT airport. What is shore pass?

I am an Indian citizen and currently staying in United States on J-1 Exchange Visitor visa. I will be traveling from Dallas Fort Worth (DFW) to New Delhi (India) on 19th July. I have a layover of 22 hours at Narita Airport. I do not plan leave the terminal, both my incoming and departure flight are from Terminal 2 at Narita airport. I have booked the flights through Japan Airlines.    Will I be requiring a transit visa?  I have heard of some rules change at Narita Airport, hence asking this as a separate question.  Also, if the visa is required is it possible to get it at on arrival at NRT or do I need to apply for visa at the Japanese Embassy at Houston?


I wonder if anyone can point me in the direction of high resolution Koppen climate maps for use in academic research. I want to accurately place c. 100 study sites from around the world in their respective climatic zones for a meta analysis I am conducting.

Have been looking around a bit for a shapefile/kml/etc file of global climatic zones (as listed here: ) -- temperature, subtropical, tropical, etcetera.  Also would be very pleased to find gis overlays detailing photoperiod areas, that sort of thing?   An online GIS service would be fine for this as well for this, as long as its a real GIS with aerial overlays etc, not a plane paper PDF deal, which is about all I can find.  One promising (but dead link) source I found before posting question:


Viewport shading (material preview) is not working, and Viewport shading (wireframe) works only in edit mode, in object mode does not work, but should work in both. Viewport shading (rendered) also does not work, it fixes by switching from eevee to cycles. The blender has been reinstalled several times, the video card driver too, and Windows has reinstalled a bunch of times. Please help solve the problem! P.S. Video with glitches is available on Google Drive at the link below

I don't know why but now, when i go in material preview or rendered (in solid mode it works fine), my object is entirely gray, or invisible idk, because it has the same color of the background. I've been working for days on this project without having this issue, it suddenly showed up. I tried opening other old projects and suddenly they all do the same so i guess it is some blender program setting that applies for all the projects, but idk how it happened cuz i didn't change anything :/, anyone got any tips?


I am passing arguments to the shell script below ./script.sh pan.tgz 192.168.3.1 ABCXYZ  #!/bin/sh echo $1 $2 $3 file=$1 host=$2 key=$3  curl -kv -o ${file} 'https://${host}/api/?type=export&category=device-state&key=${key}'   but getting error curl: (6) Could not resolve host: $host

Sometimes I see shell scripts use all of these different ways of quoting some text: "...", '...', $'...', and $"...". Why are there so many different kinds of quote being used? Do they behave differently or affect what I can do inside them?


Prove that if $f(x)$ is continuous on $[a, b]$ and $f'(x)>0$ on $(a, b)$ except at a point $c \in (a, b)$ where $f'(c)=0$, then $f$ is strictly increasing on $[a, b]$. I can prove the case without the $c$ using MVT, but not sure how to approach this particular case.

Let $f: \mathbb{R} \to \mathbb{R}$ be differentiable on $(a,b)$. Suppose $f' > 0$ on $(a,b)$ except at a point $c \in (a,b)$ (that is, $f'(c) \leq 0$).  Is $f$ increasing on $(a,b)$? Must $f'(c)$ be zero, or can it be negative?  Clearly $f$ is increasing on $(a,c) \cup (c,b)$ but I'm not sure about how the value at $c$ compares with the values at other points. And I think $f'(c)$ must be zero: If $f'(c) < 0$ then for small positive $h$ we have $\frac{f(c+h) - f(c)}{h}$ is also negative (by definition of the derivative as a limit of this ratio), so $f(c+h) - f(c) < 0$. Since $f'$ is positive on $(c,c+h)$, the Mean Value Theorem implies that $f(c+h) - f(c) = f'(d)h$ for some $d \in (c, c+h)$, and $f'(d)h$ is a product of two positive numbers, hence positive. So $f(c+h) - f(c) > 0$, a contradiction.


Our customer has a domain. Let's call it example.com.  We are running a VM in the network of our customer. Let's call it "our-vm".  The customer is accessing the vm with this name: our-vm.example.com.  The IP address is an internal for example 10.1.2.3  The name server of our customer (example.com) does not resolve the host name.  We have a VPN to our customer and are able to access 10.1.2.3 via IP address.  But I would like to access the host by name.  What I want:   our-vm.example.com should get resolved by me (running a bind in our network) www.example.com, mail.example.com and other names should get resolved by example.com   How to configure bind this way?  Sub-question: is there a name for this type of configuration?  This is not a duplicate of () because I want example.com to be handled by the customer.

I have an internal network with a DNS server running BIND, connected to the internet through a single gateway. My domain "example.com" is managed by an external DNS provider. Some of the entries in that domain, say "host1.example.com" and "host2.example.com", as well as the top-level entry "example.com", point to the public IP address of the gateway.  I would like hosts located on the internal network to resolve "host1.example.com", "host2.example.com" and "example.com" to internal IP addresses instead of that of the gateway. Other hosts like "otherhost.example.com" should still be resolved by the external DNS provider.  I have succeeded in doing that for the host1 and host2 entries, by defining two single-entry zones in BIND for "host1.example.com" and "host2.example.com". However, if I add a zone for "example.com", all queries for that domain are resolved by my local DNS server, and e.g. querying "otherhost.example.com" results in an error.  Is it possible to configure BIND to override only some entries of a domain, and to resolve the rest recursively?


I have a problem I would like to program a menu for a game console in Java, I use several JPanel and I change with frame.setContentPane (newMenu); between the JPanel now I would like that if I enlarge the JFrame that the JPanel enlarges so that the JPanel in the resolution 800x600 remains but the JFrame is for example in the resolution 1920x1080. I want to have it like RetroGames have black stripes left and right and no black stripes at the top and bottom.  Code: JFrame      frame = new JFrame(CGC_NAME + " [Version: " + CGC_VERSION + "]");     frame.setSize(DISPLAY_WIDTH, DISPLAY_HEIGHT);     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);     frame.setLocationRelativeTo(null);     frame.setResizable(false);     frame.setVisible(true);      frame.setLayout(null);     displayPanel = new JPanel();     displayPanel.setBounds(0,0, Menu.MENU_WIDTH, Menu.MENU_HEIGHT);     frame.add(displayPanel);      Menu.changeMenu(null, Menu.homeMenu);      frame.setFocusable(true);     frame.requestFocus();     frame.addKeyListener(new Keyboard());   Code JPanel      @Override protected void paintComponent(Graphics g) {     super.paintComponent(g);     renderMenu(g);      repaint(); }  protected abstract void runMenu();   protected abstract void renderMenu(Graphics g);  public static void changeMenu(Menu oldMenu, Menu newMenu) {     //CGC.frame.setContentPane(newMenu);      if (oldMenu != null) {         CGC.displayPanel.remove(oldMenu);     }      CGC.displayPanel.setLayout(new BorderLayout());     CGC.displayPanel.add(newMenu, BorderLayout.CENTER);     CGC.frame.revalidate();     CGC.frame.repaint();     newMenu.runMenu(); }   Can someone help me? Cortablo

I have a JPanel subclass on which I add buttons, labels, tables, etc. To show on screen it I use JFrame:  MainPanel mainPanel = new MainPanel(); //JPanel subclass  JFrame mainFrame = new JFrame(); mainFrame.setTitle("main window title"); mainFrame.getContentPane().add(mainPanel); mainFrame.setLocation(100, 100); mainFrame.pack(); mainFrame.setVisible(true); mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);   But when I size the window, size of panel don't change. How to make size of panel to be the same as the size of window even if it was resized?


I have submitted a revised manuscript to an international journal of quantum chemistry at 8 August. My articles status still remain under review, I also don't know my article get accepted or rejected, I feel anxiety and cannot sleep well in this 3 weeks since this is my first articles. Should I write a polite inquiry email to the editor from that publisher to ask the status for my revised manuscript status? Thank you for advice.

What steps does a manuscript typically go through from submission to publication (or rejection) in a typical journal? How are these steps referred to, in particular by editorial systems, and how long do they each typically take?  Note that this question is about the typical situation and hence not about:   Journals with an atypical workflow, e.g. those that allow for an instantaneous reviewer–author interaction. Exceptional steps or rare occurrences such as withdrawal or .   This is a canonical question on this topic as per . Due to its nature, it is rather broad and not exemplary for a regular question on this site. Please feel free to improve this question.


I have a very basic question about Renormalization in Quantum Field Theory. Consider the following passage (about $\phi^4$ theory) from Zee's  (from Chapter III.3):     Shouldn't we start out with a zeroth order theory already written in terms of the physical mass $m_{P}$ and physical coupling $\lambda_{P}$ that experimentalists actually measure, and perturb around that theory? Yes, indeed, and this way of calculating is known as renormalized or dressed perturbation theory, or as I prefer to call it, physical perturbation theory. We write   $$ \mathcal{L} = \tfrac{1}{2} (\partial \phi)^2 - \tfrac{1}{2}m_{P}^2 \phi^2 - \frac{\lambda_{P}}{4!}\phi^4 + A (\partial \phi)^2 + B \phi^2 + C \phi^4 \ . $$   The factors $A$, $B$, $C$ are calculated iteratively in perturbation theory and designed at each order to cancel out the divergences that occur in the loop computations.   My question is, if we perturb about the physical theory, what justifies the use of perturbation theory? I thought that perturbation theory is only justified when the corrections to the free theory are "small" $\to$ here this doesn't seem to be the case to me since the ``couplings'' $A$, $B$, $C$ don't seem to be small, as I understand it they are divergent quantities which are functions of the cutoff/regulator used  ($A$ and $C$ are dimensionless, so I think they are actually just large numbers - while $B$ has mass dimension 1 so I actually don't know what it means for $B$ to be small here).

The idea of a perturbation series in powers of a coupling $\alpha\ll1$ (for example, the fine structure constant in QED) make sense if the contribution of $(n+1)^{th}$ term in the series is smaller than the contribution of $n^{th}$ term. Now, the tree-level amplitude for a QED process is finite. However, at $\mathcal{O}(\alpha^2)$, the contribution from the S-matrix to the amplitude is divergent (all diagrams with loops are divergent because loop momentum can be arbitrarily high). How does perturbation theory make sense in QED (or in any quantum field theory)?


Newton's second law states $\vec F  \propto \vec a$. The proportionality constant is defined as the mass ($m$) of the particle on which the force ($\vec F$) is acting and whose acceleration ($\vec a$) is being measured. Therefore, a definition such as $\vec F = m^2 \vec a$ would be consistent with Newton's second law.  what problem will "$\vec F = m^2 \vec a$"  cause in the formulation of mechanics. What about a multi-particle system.

It seems intuitive that $a\; \propto \frac{F}{m}$, as the greater the force that is applied on an object, the greater its acceleration will be. Inversely, the greater the mass of the object, the slower the acceleration will be.  However, when rewriting proportions as equations, you must introduce a constant of proportionality, and in this case of a direct proportion, if $a \propto \frac{F}{m}$ then when rewriting as an equation you will have $$a = k\cdot\frac{F}{m}$$  In order to get the standard formula $F = ma$ this constant must be $1$. However, how do we know that this is the case? How do we know that the constant isn't $2$ and the formula $F = \frac{1}{2}ma$, for instance?


I am due to run a game at a convention in the new year and want to pull out all the stops to make it memorable. One idea I have is to actually produce a potion for the player to drink once the character has found it. I have done this once before at my weekly game where I used an ornate balsamic vinegar bottle and papaya juice with purple food colouring and it worked fine, but I want to see if I wan take it to the next level.  So that was the background, here are my questions:   Where can I find affordable bottles with a fantasy potion look to them? What substance would look and taste interesting in this situation? Is it just a bad idea to try get a player I haven't met before to drink an potion? Something tells me some people might be sceptical.

I'd like to give my group some realistic looking potions as handouts.  Does anyone have tips on how I could make these look awesome?


I am reading The C Programming Language (K&R). I am trying to understand how EOF works and I believe that upon encountering Ctrl + D at the beginning of a line, EOF is triggered. However at the end of a line, it requires the user to enter Ctrl + D twice. First to flush the input and the second to trigger EOF.  The following program reads input lines from the console and prints the longest. I don't understand why I have to enter Ctrl + D thrice to trigger EOF.  #include <stdio.h>  #define MAXLINE 1000  int getline(char[]); void copy(char[], char[]);  int main() {     int len, max;      char line[MAXLINE];     char longest[MAXLINE];      max = 0;      while( (len = getline(line)) > 0)         if(len > max)         {             max = len;             copy(longest, line);         }      if(max > 0)         printf("%s", longest);     return 0;  }  int getline(char line[]) {     int c, i;     i = 0;      for(i = 0; i < MAXLINE - 1 && (c = getchar())!=EOF && c!='\n'; ++i )         line[i] = c;     if(c == '\n')     {         line[i] = c;         ++i;     }     line[i] = '\0';     return i; }  void copy(char to[], char from[]) {     int i = 0;      while( (to[i] = from[i]) != '\0')         ++i; }

I am studying for an exam and I am confused as to how canonical vs. non-canonical input/output works in Unix (e.g., curses).  I understand that there is a buffer to which "line disciplines" are applied for canonical input.  Does this mean that the buffer is bypassed for non-canonical input, or does it simply mean that no line disciplines are applied?  How does this process differ for input and output operations?  In the curses programs I have worked with that demonstrate canonical input, the input typed by a user is automatically entered either after a certain number of characters have been typed or a certain amount of time has passed.  Are either of these things considered "line disciplines" or is this something else entirely?


I have a display as in photo I sent you. But it has no label so I can't get data sheet. It has seven pins only. How to know  its pin  configurations? Please help me.

Bought some "music speaker" thingies, some with bluetooth and some without. They are cheap, for sure, about 3 or 4 euro's. With some capacitor tweaks, they seem to be very plausibel to use (why is the output on these cheap things always tiny and limited?).  On these devices they use a very tiny, nice and bright display, with 7 legs, charlieplexed I suppose (wiggle it to see any screen update), 35 segments. Cannot read the number on the used chip (it's from JL), very hard to recognize (even when using a microscope) and the display doesn't have any partnumber on it either, however, these seem to be identical except the face plate on these components.   The displays are very interesting, just 7 pins to do the display job, in just one package. I want to buy these things (cannot find it, doesn't know the name and cannot find a datasheet either).   Next thing I want to do is to interface with these devices by reading the display (with a MCU for example) so I am able to read the state of the device and what it is doing. This is a difficult task without any datasheet.   Does somebody know the name of this component, is there a datasheet available somewhere?  Photo gallery of the display:          Product picture:


to be more specific ,I want to display contents of files from output of find command,I tried the following commands but they don't get my work done   cat < find . -name "*.txt" find . -name "*.txt" | cat

I'd like to find the files in the current directory that contain the text "chrome".  $ find . -exec grep chrome find: missing argument to `-exec'   What am I doing wrong?


Hi I am new to Blender and I am studying materials at the moment.  My version of Blender is not showing the attributes in full on the attribute editor. I can't see the surface, wire, volume and halo options, I can't see the diffuse and specular as such.

Complete beginner here.  I'm trying to follow  tutorial on Anisotropic shaders, but my property panel looks nothing like the property panel in the tutorial.  For example, when creating a material, this is what his property panel looks like:    But this is what mine looks like, if I follow the same path:    I'm sure I'm missing something obvious.  How can I see the property panel shown in the tutorial?


I already completed Borderlands 2 on normal mode many month's ago. But without any DLC. Now I have all released 4 DLC and my version is 1.7.0. I want start play again from level 1. But I'm completely confusing how to play. Can you tell me like below:   Complete all main & optimal missions in normal mode. Teleport to "name here" for "name here" DLC, and complete it. Teleport to "name here" for "name here" DLC, and complete it. Teleport to "name here" for "name here" DLC, and complete it. Teleport to "name here" for "name here" DLC, and complete it. Change difficult mode to "mode here". Repeat again.   I don't know which DLC requires what level. I don't know how to reach those DLC zones. I don't know which DLC should I play first and which one later.  edit: wtf is that playthrough 1, playthrough 2, playthrough 2.5 things?

I'm late to the Borderlands 2 party, but I picked up the Season Pass for a steal.  I'm still only in the teens as far as my level is concerned.  However, there are now 3 DLC packs out and I've got them all installed.  Sometimes it's tempting to go away from the main quest and just jump into something new and potentially interesting.  In BL1, I played through the DLC between playthroughs of the game, treating the add-ons like continuations of the game post-final-boss.  I'm not sure if this is a good idea in BL2 (or even if it was smart in BL1, honestly...)  Is there a recommended level for starting the DLCs?  Will I encounter enemies that are too hard if I go early, or too easy if I go late?  Are there some weapons or quest rewards that I really can't get the most of until after I'm a certain level?