Shell script throws a not found error when run from a sh file. But if entered manually the commands work

I'm trying to use the following script to generate a sitemap for my website. When I run it as sh thsitemap.sh I get an error like this and creates an empty sitemap.xml file:  thsitemap.sh: 22: thsitemap.sh: [[: not found thsitemap.sh: 42: thsitemap.sh: [[: not found thsitemap.sh: 50: thsitemap.sh: Syntax error: "(" unexpected   But as the same user root when I manually copy and paste these lines on the terminal, it works without any error and the sitemap.xml file have all the urls. What's the problem? How can I fix this?  #!/bin/bash ############################################## # modified version of original http://media-glass.es/ghost-sitemaps/ # for ghost.centminmod.com # http://ghost.centminmod.com/ghost-sitemap-generator/ ############################################## url="techhamlet.com" webroot='/home/leafh8kfns/techhamlet.com' path="${webroot}/sitemap.xml" user='leafh8kfns'       # web server user group='leafh8kfns'      # web server group  debug='n' # disable debug mode with debug='n' ############################################## date=`date +'%FT%k:%M:%S+00:00'` freq="daily" prio="0.5" reject='.rss, .gif, .png, .jpg, .css, .js, .txt, .ico, .eot, .woff, .ttf, .svg, .txt' ############################################## # create sitemap.xml file if it doesn't exist and give it same permissions # as nginx server user/group if [[ ! -f "$path" ]]; then     touch $path     chown ${user}:${group} $path fi  # check for robots.txt defined Sitemap directive # if doesn't exist add one # https://support.google.com/webmasters/answer/183669 if [ -f "${webroot}/robots.txt" ]; then SITEMAPCHECK=$(grep 'Sitemap:' ${webroot}/robots.txt)     if [ -z "$SITEMAPCHECK" ]; then     echo "Sitemap: http://${url}/sitemap.xml" >> ${webroot}/robots.txt     fi fi ############################################## echo "" > $path  # grab list of site urls list=`wget -r --delete-after $url --reject=${reject} 2>&1 |grep "\-\-"  |grep http | grep -v 'normalize\.css' | awk '{ print $3 }'`  if [[ "$debug" = [yY] ]]; then     echo "------------------------------------------------------"     echo "Following list of urls will be submitted to Google"     echo $list     echo "------------------------------------------------------" fi  # put list into an array array=($list)  echo "------------------------------------------------------" echo ${#array[@]} "pages detected for $url"  echo "------------------------------------------------------"  # formatted properly according to # https://support.google.com/webmasters/answer/35738 echo "<?xml version=\"1.0\" encoding=\"UTF-8\"?> <urlset xsi:schemaLocation=\"http://www.sitemaps.org/schemas/sitemap/0.9  http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns=\"http://www.sitemaps.org/schemas/sitemap/0.9\">" > $path  echo '     ' >> $path;    for ((i=0;i<${#array[*]};i++)); do echo "<url>     <loc>${array[$i]:0}</loc>     <lastmod>$date</lastmod>     <changefreq>$freq</changefreq>     <priority>$prio</priority> </url>" >> $path    done echo "" >> $path echo "</urlset>" >> $path  # notify Google # URL encode urls as per https://support.google.com/webmasters/answer/183669 if [[ "$debug" = [nN] ]]; then     wget  -q --delete-after http://www.google.com/webmasters/tools/ping?sitemap=http%3A%2F%2F${url}%2Fsitemap.xml      rm -rf ${url} else     echo "wget  -q --delete-after http://www.google.com/webmasters/tools/ping?sitemap=http%3A%2F%2F${url}%2Fsitemap.xml"      echo "rm -rf ${url}" fi echo "------------------------------------------------------"  exit 0


I am running VM Workstation 12 Player and have installed Ubuntu 16.10 on the VM.  I have made an extended partition for the swap space after having had to remove the swap partition in order to extend the primary partition space.  I enter   fdisk -l   and get  Disk /dev/sda: 80 GiB, 85899345920 bytes, 167772160 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x7d4da0a8  Device     Boot     Start       End   Sectors  Size Id Type /dev/sda1  *         2048 157700095 157698048 75.2G 83 Linux /dev/sda2       157700096 159793151   2093056 1022M  5 Extended   Yet, when I type  sudo mkswap /dev/sda2   I get  mkswap: error: swap area needs to be at least 40 KiB   It seems that I have just over 1 GB of space on /dev/sda2


Can anyone walk me through the process of installing Bitcoin on Ubuntu? I'm new to linux, and this is really all I want to do with this computer.


Any fix for a warped carbon steel fry pan?

I bought a De Buyer 14" Mineral B Round carbon steel fry pan approximately five years ago. I've used it a fair bit, but recently I think I warped it in the oven when I put it under a broiler for a bit. Now it wobbles when I put it down on a flat surface.  Is there any remedy for this? Or should I recycle it?


I'm new to Ubuntu. I tried installing it with Windows 8.1, but failed I lost all my files.  I have successfully formatted my PC and installed Ubuntu, but how do I install codecs to play audio and videos files ?


How do I boot into Ubuntu (after installing, it still just boots to Windows)?

I've successfully installed Ubuntu (or so I'm told) on my Dell laptop alongside a clean Windows XP install. When I turn on the computer it boots directly into Windows with no options given to boot into Linux. What am I missing?


Number of Subgroups for rational numbers $\mathbb{Q}$ of finite index

Show that the only subgroup of ($\mathbb{Q}$; +) of finite index is $\mathbb{Q}$ itself where + is the usual addition.  I have seen this question in my exam of abstract algebra. As I know the index here means the number of different cosets that can be generated from a group. Any idea


Display style in text, but at text style size

I would like to write $\sum_i$ to be displayed as \displaystyle $\sum_i$ but at the size of $\sum_i$. How can I do that?  I could maybe use a subscript command, but that is not my question. My question is more generic about the display style within the text style at the size of the text style.


Inter-US air travel on a Visa Waiver (VWP)?

Im flying to Texas, El Paso on the 15th of October 2014, this is on a visa waiver program.  I wish to fly to Arizona, Sky Harbor on the 17th of October 2014 for the day to say Hi to long distance friends and return to El Paso later in the day.  Question is;     Can I fly inside the USA with my Visa Waiver?


Prove or Disprove: There are infinitely many integers $n$ such that the three integers $n$, $n+2$, $n+4$ are all prime.

Prove or Disprove: There are infinitely many integers $n$ such that the three integers $n$, $n+2$,$n+4$ are all prime. (Suggestion: Try some sample values of $n$ and look for a pattern.)


Suppose I have an eigenvalue $\lambda$, now I want to determine the number of Jordan blocks corresponding to that eigenvalue, as well as size of each block. I know that:  number of blocks is equal to the number of eigenvectors there are $\dim \ker (A - \lambda I)^k - \dim \ker (A - \lambda I)^{k-1}$ blocks of size at least $k$ Why exactly are those statements true. Could someone provide me with a proof or at least some reasoning behind this?


I'm using VS code installed via snap. The latest version has an annoying bug in it and I want to revert to the previous version, but I don't see a way to tell snap to install a specific version. All I see with snap info are the different channels which all yield to the latest version. Also on the  I can't select another version. In the snap docs it says that I could revert, but this doesn't work for me, as there is no prior version installed. I can download a snap with the specific version from the VS code website, , but I personally would prefer to handle this by snap directly. There seem to be some people with the same problem, but I didn't find a working answer:     The question summed up is: Is there a possibility to revert to an older snap version and if yes, how to do that?


Precision Shunt Regulator Increasing Voltage overtime

I want to have a stable voltage of 2.47V using TLV431AC which is a precision voltage-adjustable shunt regulator.   I am able to get it by putting a 5k potentiometer and a 500 ohm resistor in series connected to the REF pin of the regulator. Since the cathode current limit is 15mA, I have used a 500 ohm resistor between the source and the CATHODE pin to limit the current to about 10mA.    On choosing the right load capacitor for stability, I have referred to the table to the datasheet and it looks like 10uF is outside the unstable range of values so I chose that one as my load capacitor.  My problem is while the time goes by, my output is slightly increasing by a few millivolts and would not stop which I think is bad because I am planning to use the output of this circuit as a voltage reference. What could be the problem? Is there anything wrong with my circuit?


After upgrading to 12.10 usb drives fail to mount

Following upgrade to 12.10, my usb drives - both pen drives and a usb hard drive - fail to mount with the error message: Unable to mount *name of drive* volume Adding read ACL for uid 1000 to '/media/*my home file name*' failed: Operation not supported  This is on a desktop Dell Inspiron 530.  I also have a Dell Inspiron Mini 10 netbook which I also upgraded to 12.10 (slightly smaller installation on a flash hard drive). all devices mount automatically without problems on this computer.


Proving that the dual of the $\mathcal{l}_p$ norm is the $\mathcal{l}_q$ norm.

Let $\| \cdot \|$ be a norm on $\mathbb{R}^n$. The associated dual norm, denoted $\| \cdot \|_*$ is defined as $\| z \|_* = \sup\{ z^{t} x : \| x \| < 1 \}$.   Does someone know how to prove that the dual norm of the $\mathcal l_{p}$ norm is the $\mathcal l_{q}$ norm? I read about norms and it was stated without proof in a book.


Hide a Subdomain from Google/Search Engine SEO Result?

I have a subomain which I do not want to be listed in any search engine result. Let say I have:   http://www.example.com http://child.example.com   How can I hide all URLs of child.example.com domain which are currently showing in the search engine results?


Why/How are there infinite points in a line segment?

A line may have infinite points becauase it may be expanded.But in case of a line segment it has 2 distinct points which are not movable.The distance between the end points in finite and known.  But still why do people(in my school) say that there are infinite points in a line segment.When I ask the teacher,she says you will learn at higher levels(what a genius way to get rid of question).


How to align div horizontally in React JS?

Below is just a snippet of my code:  return(

row1

row2

row3

 );   I tried this, but it displays in vertical. Image attached below


How does one split a title into two lines?

I am using the tikzposter package, and I was wondering how one could split the title into two lines:  \documentclass[24pt, a0papper, portrait]{tikzposter} \usepackage[utf8]{inputenc}  \title{Extreeeeeeeeeeeeeeeeeeemly Looooooooooooooooooooooooooooooong Tiiiiiiiiiiiiiiiiiiiitle Here} \author{ShareLaTeX Team} \date{\today} \institute{ShareLaTeX Institute}  \usetheme{Board}  \begin{document}  \maketitle  \end{document}


Phone still stuck in a bootloop after flashing official firmware with Odin!

I successfully flashed a stock ROM on my Galaxy Note 4 using Odin 3.13.1 but, unfortunatelly, the bootloop is not gone.  Device info:    SM-N910C unrooted Android 6.0.1 Marshmallow   Bootloop sequence: Samsung boot screen —> Android is starting... Optimising Apps 2 of 2. —> Android is starting... Starting apps. —> LOOP  What are my options to restore my personal data from now on?


How to show $\lim_{n\to \infty} \frac{x^n}{n!}=0$

I know how to show $\lim_{n\to \infty} \frac{x^n}{n!}=0$ from the perspective of series. Namely use the ratio test to show $\sum\frac{x^n}{n!}$ is convergent, then the nth term must tends to 0. But I remember I have seen another way to do it in the forum. I think this question may duplicate, but the 'similar question' doesn't show. If it does duplicate, I apologize.


Need to contact rockstar game services because my vehicle was replaced with another and I can’t get my car back


Physical meaning of magnetic vector potential

Can anyone give me an intuition of why the magnetic vector potential $A$ is sometimes interpreted  as the electromagnetic momentum ?  I don't know analytical mechanics, just classical electromagnetism


No field properly between $\mathbb Q$ and $E$ iff $G(K/\mathbb Q) \cong A_4$ or $S_4$

Let $f(x) \in \mathbb Q[x]$ be irreducible of degree 4. Let $\alpha$ be a root of $f(x)$. Let $E = \mathbb Q(\alpha)$ and let $K$ be the splitting field of $f(x)$ over $\mathbb Q$. Prove that there is no field properly between $\mathbb Q$ and $E$ if and only if $G(K/\mathbb Q) \cong A_4$ or $S_4$.  At this point in the course we've just gone through the Fundamental Theorem of Galois Theory. I'm fairly lost, so any hints, sketches of a proof would help. Thanks!


Which is right: "In one of the computers" or "On one of the computers"?

Do you say IN one of the computers or ON one of the computers? Which is right?


UK visa application : Travel history UK question?

The travel history to UK states if you were refused a visa to uk. Our last vist visa which got refused and then we complained to MP and complained to UK visas and immigration complaint department and then our decision was overturned. So is this still considered visa refusal for that part of application and in notes to state that visa did get approved after complaint ?


Should I use plural or singular with "or"?

Which of these sentences are correct?  1. The songs or the title of the playlist was updated. 2. The songs or the title of the playlist were updated. 3. the title or the songs of the playlist was updated. 4. The title or the songs of the playlist were updated.


When making multiple attacks, does advantage from being unseen apply to all attacks?

When you dual-wield or multiattack somebody who can't see you, are both/all attacks with advantage? We are using facing rules, so attacking silently from behind is a common situation I expect to bring this up.  To clarify, I'm not talking about sneak attack here. I know that you can only sneak once per turn. I'm just wondering if I jump somebody from the shadows and I hit them with multiple attacks, if they are all with advantage. Are they?  If advantage is denied on second attack because the opponent wouldn't be unaware anymore, or would turn and defend, does losing advantage happen even in case the first attack (with advantage) missed?


Problem adding Image to hyperlink in Google Sheets

I want an image to be my hyperlink in Google sheets.  Here is my formula:  =HYPERLINK("google.com/de", IMAGE("http://s5.favim.com/orig/69/hi-love-quote-start-Favim.com-658946.jpg"))   The image shows up on the sheet - but it is no longer a hyperlink.


What will happen if I install Windows 8.1 32 bit on a 64 bit PC?

I found that my PC can run a 64 bit OS, but my RAM is only 1.5 GB. Am I doing something wrong by installing windows 8.1 32 bit? Is my system capable of performing better? What happens if I install the 32 bit version of the OS on a 64 bit processor?    and these are my specifications:


Does an injective endomorphism of a finitely-generated free R-module have nonzero determinant?

Alternately, let $M$ be an $n \times n$ matrix with entries in a commutative ring $R$. If $M$ has trivial kernel, is it true that $\det(M) \neq 0$?     deals with the case that $R$ is a polynomial ring over a field. There it was observed that there is a straightforward proof when $R$ is an integral domain by passing to the fraction field.  In the general case I have neither a proof nor a counterexample. Here are three general observations about properties that a counterexample $M$ (trivial kernel but zero determinant) must satisfy. First, recall that the  $\text{adj}(M)$ of a matrix $M$ is a matrix whose entries are integer polynomials in those of $M$ and which satisfies  $$M \text{adj}(M) = \det(M).$$  If $\det(M) = 0$ and $\text{adj}(M) \neq 0$, then some column of $\text{adj}(M)$ lies in the kernel of $M$. Thus:     If $M$ is a counterexample, then $\text{adj}(M) = 0$.   When $n = 2$, we have $\text{adj}(M) = 0 \Rightarrow M = 0$, so this settles the $2 \times 2$ case.   Second observation: recall that by Cayley-Hamilton $p(M) = 0$ where $p$ is the characteristic polynomial of $M$. Write this as $$M^k q(M) = 0$$  where $q$ has nonzero constant term. If $q(M) \neq 0$, then there exists some $v \in R^n$ such that $w = q(M) v \neq 0$, hence $M^k w = 0$ and one of the vectors $w, Mw, M^2 w,\dots, M^{k-1} w$ necessarily lies in the kernel of $M$. Thus if $M$ is a counterexample we must have $q(M) = 0$ where $q$ has nonzero constant term.  Now for every prime ideal $P$ of $R$, consider the induced action of $M$ on $F^n$, where $F = \overline{ \text{Frac}(R/P) }$. Then $q(\lambda) = 0$ for every eigenvalue $\lambda$ of $M$. Since $\det(M) = 0$, one of these eigenvalues over $F$ is $0$, hence it follows that $q(0) \in P$. Since this is true for all prime ideals, $q(0)$ lies in the intersection of all the prime ideals of $R$, hence     If $M$ is a counterexample and $q$ is defined as above, then $q(0)$ is nilpotent.    This settles the question for reduced rings. Now, $\text{det}(M) = 0$ implies that the constant term of $p$ is equal to zero, and $\text{adj}(M) = 0$ implies that the linear term of $p$ is equal to zero. It follows that if $M$ is a counterexample, then $M^2 \mid p(M)$. When $n = 3$, this implies that $$q(M) = M - \lambda$$  where $\lambda$ is nilpotent, so $M$ is nilpotent and thus must have nontrivial kernel. So this settles the $3 \times 3$ case.   Third observation: if $M$ is a counterexample, then it is a counterexample over the subring of $R$ generated by the entries of $M$, so     We may assume WLOG that $R$ is finitely-generated over $\mathbb{Z}$.


Explicit bijection $\Bbb R^{\Bbb R} \to P(\Bbb R) $.

Is there any simple way to construct a bijective function: $\Bbb R^{\Bbb R} \to P(\Bbb R) $ to see that $\Bbb R^{\Bbb R}$ is isomorphic to $P(\Bbb R)$?


My wifi adapter RTL8821CE doesn't work. I managed to solve this issue in Ubuntu 18.04, but now after installing 19.04 it's not working anymore. Does anyone know how to solve this issue?  The output for lshw -c network is   $ sudo lshw -c network    *-network UNCLAIMED               description: Network controller        product: RTL8821CE 802.11ac PCIe Wireless Network Adapter        vendor: Realtek Semiconductor Co., Ltd.        physical id: 0        bus info: pci@0000:01:00.0        version: 00        width: 64 bits        clock: 33MHz        capabilities: pm msi pciexpress cap_list        configuration: latency=0        resources: ioport:3000(size=256) memory:a1100000-a110ffff   *-network        description: Ethernet interface        physical id: 3        logical name: enp0s20f0u1        serial: 96:c8:e8:52:94:a7        capabilities: ethernet physical        configuration: broadcast=yes driver=rndis_host driverversion=22-Aug-2005 firmware=RNDIS device ip=192.168.42.79 link=yes multicast=yes   The output of rfkill list all is:  $ rfkill list all 0: hci0: Bluetooth     Soft blocked: yes     Hard blocked: no


Can't open a folder in windows 7 by double click

Can't open a folder in windows 7 64bit, by double clicking, it shows me that the default option for opening folder is "cmd" (it's highlighted when i'm right clicking a folder, and the "open" option comes next). I've tried running some registry fixing tools, but it didn't fix it. Can someone suggest me what should I do.


Continuous function which maps (0,1] to {0}, (0,1), [0,1), [0,1]

Let $f: \mathbb R \to \mathbb R$ be a continuous function. Which one of the following sets cannot be the image of $(0,1]$ under $f$?   $\{0\}$ $(0,1)$ $[0,1)$ $[0,1]$.   We know that $(0,1]$ is neither open nor closed, since $f$ is continuous, "every inverse mapping of closed set is closed" by the result above, $\{0\}, (0,1), [0,1]$ are sets that cannot be image of $(0,1]$. Am I right?  My argument: Inverse exists only when function is one one and onto, so will there be continuous function such that inverse never exists but the image of $(0,1]$ be one of the above three sets?


Why does a Gauge group have to be a compact Lie group?

In Topological Solitons by Nicholas Manton where he considers "compact Lie groups" to be the gauge groups  for generalizing gauge theoretic concepts. But, he does not mention why that condition is required  The killing is non-degenerate as per the requirement of the kinetic terms.Kinetic part of the Yang Mills action $$ \int Tr({\bf{F^2}}) dV$$ to be positive definite. I do think there is relevancy of the compactness of the lie group as apposed to the views in   I've found this result.      For compact groups the Killing form will be negative definite   I'm not able to find any such result for a Lie group. Can anyone tell me how this and the above result are result and its implementation in gauge theory?  Thanks, Sai


Can I resize multiple images in a directory to 160x160 at once?

I want to resize multiple images that are stored in multiple sub folders in a directory. And I want to replace those images with resized ones by deleting the original ones  Why?  I’ve folder icons for a lot of content in a separate partition. Some of these images are around a megabyte and are 500x500 which is in my opinion overkill for folder icons on 1080p display and I think it’s also reducing performance of nautilus and taking up some valuable space  How is the folder structure?  ├── [4.0K]  Zombieland (2009) H │   ├── [664K]  .folder.png │   └── [606M]  Zombieland (2009) H.mkv └── [4.0K]  Zootopia (2016)     ├── [203K]  .folder.png     ├── [2.7G]  Zootopia (2016).mkv     └── [119K]  Zootopia (2016).srt   I want those .folder.png ‘s resized to 160x160. Answer should work on Deep directories.  Other data   Images are generally .png but also .icns, .ico Images can be stored in really deep directories all the images have 1:1 aspect ratio all the images are named .folder.extension There is an  but I think it only works on one image   I'll be glad to provide more information


Geometric Intuition behind trace and matrix non-commutativity

My intuition of trace is that it is essentially asking, for each basis, where does this basis vector go, and what is the new vector's component in its original basis. Then, trace is a sum of those terms.  And matrix non-commutativity makes sense. You apply one transformation, then the next. And this can lead to differences in the result of $AB$ and $BA$.  But if matrices multiplication is non-commutative, then why, in light of my intuition of trace, is trace cyclic. $$\operatorname{trace}(AB)=\operatorname{trace}(BA)$$  I can show it numerically, but I'd like to be able to think of it in a more intuitive and geometric way.


I would like to create an environment having the following role: create an exercise (called "exo" in the sequel) and a grid with a prescribed number of lines. My environment exo works fine, but not with the grid. I tried  \newenvironment{exoQuadrill}[1]% {\begin{exo}}% {\end{exo} \smallbreak\begin{tikzpicture}[scale=0.5,gray] \draw(0,0) grid (33.4,#1); \end{tikzpicture}\medbreak}   It doesn't work (error : "illegal parameter number"), but it is if I don't specify the number of lines:   \newenvironment{exoQuadrill}[1]% {\begin{exo}}% {\end{exo} \smallbreak\begin{tikzpicture}[scale=0.5,gray] \draw(0,0) grid (33.4,13); \end{tikzpicture}\medbreak}


Welcome back message suggests to upvote questions and answers even when questions are locked

I just opened a URL to a question on programmers.SE and got the message:     But the question was locked, so I couldn't do what it asked me to do.  I consider this to be a very minor edge case bug and it's likely not worth investing developer time into it. But since this  I guess it's worth reporting even if it's just for making you aware of it.


How do I wash my kids' hair without them screaming their lungs out?

My kids are both under six years of age. Occasionally, when they are really dirty and sweaty, I need to wash their hair with shampoo. The trouble starts when I try to wash the shampoo out of their hair, by using a big scoop to pour water over their hair. Inevitably, some water gets into their eyes, and they start screaming as if it is the end of the world. I am able to use a small towel to wipe the water out of their eyes but only after some water has already gotten in their eyes and the screaming has begun.  How can I wash my kids' hair without traumatizing them?


How does Stack Exchange attempt to prevent low-quality questions and answers?

Due to its massive (and growing) size, there are a lot of low-quality questions and answers appearing on Stack Overflow.  I'm concerned that an influx of low-quality questions and answers create a lot of work for our users and moderators and can potentially damage our expert Q&A ecosystem.  Is there some way we can prevent these low-quality questions and answers from appearing on the site?   So:    What current processes are used to block these low-quality questions and answers? If the current processes are inadequate, how can they be improved?


I have no space for upgrade. I was extended my disk and gparted it, but still no space for upgrade

I have 10 GB Ubuntu 16.04 LTS on virtual disk in Virtual Box.   When I am trying upgrade, installer says me not enough space. I was enlarged disk image for 20 GB and Gparted partitions to whole new space. But still can´t upgrade and no space error:


Hey I’m an Dual citizen and my question is I’m going to Mexico in July but I don’ have a current us passport but I do have a Mexican passport. I can’t get MY us passport renewed since I owe Child  support. Can I fly from Chicago to Guadalajara using my Mexican passport and retrurn through Tijuana San Diego using my sentri card ?


Evaluation of $ \int\frac{\sqrt{\sin x}}{\sqrt{\sin x}+\sqrt{\cos x}}dx$

Evaluation of $\displaystyle \int\frac{\sqrt{\sin x}}{\sqrt{\sin x}+\sqrt{\cos x}}dx$  $\bf{My\; Try::}$ Given $\displaystyle \int\frac{\sqrt{\sin x}}{\sqrt{\sin x}+\sqrt{\cos x}}dx = \int \frac{\sqrt{\tan x}}{1+\sqrt{\tan x}}dx$  Now Let $\displaystyle \tan x = t^2\;,$ Then $\sec^2 xdx = 2tdt$ or $\displaystyle dx = \frac{2t}{1+t^4}dt$  So Integral is $\displaystyle \int\frac{t}{1+t}\cdot \frac{2t}{1+t^4}dt = 2\int\frac{t^2}{(1+t)\cdot  (1+t^4)}dt$  Now How can I solve after that  Help me   Thanks


Prove that $\langle 2+i\rangle$ is a maximal ideal for Gaussian Integers $\Bbb Z[i]$

There is a solution which starts by taking $\langle 2+i\rangle$ as a subset of $\langle a+ib\rangle $ and then proceeds as, Hence $(2+i)$ can be represented as multiple of $(a+ib)$. I understand till this part.  Next it proceeds, $(2+i)=(a+ib)(c+id)$. I don't understand this line.  Shouldn't it proceed by multiplying $(a+ib)$ with an integer.  Why is $(a+ib)$  multiplied with another complex number?


How do spell attacks work?  Roll 1D20 + your spell Attack Modifier.  Spell Attack modifier = 2 + 2 (Charisma Modifier) For a total of 4.  I roll a D20 and get 10. Add 4, to get a total of 14. What I am attacking say has an AC of 14. It hits.   My question is: is this interpretation of how spell attacks work correct?  Spell attacks are roll D20 + Add Spell Attack modifier.  Trying to understand how spell attacks work.


Is it possible to intuitively explain why conditional probability/expectation depends on sigma algebra

Is it possible to intuitively explain why conditional probability/expectation $(P(A|X)$ or $E[Y|X])$ depends on sigma algebra on which it is conditioned not the value of the random variable ?  Formally, it is due to Radon-Nykodin theorem. But in Breiman it says that the intuition behind this is that the relevant information contained in knowing $X(\omega)$ is the information regarding the location of $\omega$. What is the meaning of it.


Multi-level wildcard DNS matched by *.domain.com?

Q1: Does a DNS rule for *.domain.com match multi-level domain names? In other words, if I just set *.domain.com in my DNS records, will it match all of:  a.domain.com b.a.domain.com c.b.a.domain.com   as many levels deep as needed, with just that one wildcard DNS specifier?  We have a use case for multi-level DNS and I would like to confirm that we are doing the right thing in setting one wildcard DNS setting for the root domain.  Q2: will this work with round-robin DNS?


Conference call combining regular Skype and Skype for Business callers

If you use Skype for Business, apparently it is  to have a conference call and include regular Skype callers. I would like to be able to include both Skype for Business and regular Skype callers on a call. Can I do this with regular Skype, so I'd initiate the call in regular Skype and add Skype for Business callers?


Is removing old linux-headers and linux-image packages safe?

I started using Ubuntu and like it so far. I got my first system at a point where problems would really hurt. Normally I do the apt-get upgrade stuff quite brain-off but this here made me feel a bit uncertain. The following packages were automatically installed and are no longer required:   linux-headers-4.15.0-29 linux-headers-4.15.0-29-generic linux-image-4.15.0-29-generic linux-modules-4.15.0-29-generic linux-modules-extra-4.15.0-29-generic Use 'sudo apt autoremove' to remove them.  I believe that newer version of this modules are installed and used already and that this old ones can be removed. But that is just me theory. When running autoremove it says that 335 MB will be freed. Is this safe or not? Update: I went for the autoremove with purge (even if I have enough space) I just seem to be greedily. It then popped up a purple screen asking me: A new version of /boot/grub/menu.lst is available, but the version installed currently has been locally modified. What would you like to do about menu.lst?  install the package maintainer's version keep the local version currently installed show the differences between the versions show a side-by-side difference between the versions show a 3-way difference between available versions do a 3-way merge between available versions (experimental) List item start a new shell to examine the situation  if I choose option 2: keep the local version, will it keep revert back to 4.15.0-29? what should I do. I'm sure this is just a small thing but I dont want this system to have short or longterm issues. Update: I compared both versions: one was the grub list and the other was some tmp list. one was version 29 and the other had version 34. I pressed: keep the local version currently installed twice and rebootet. $ uname -r 4.15.0-34-generic  hope that grub list is okay and its not the tmp list. Nevertheless I wanted to thank all you guys for the amount of very detailed answers. I felt a bit bad for all the time you spent answering me the initial question. But this seems to stand up for a decent community.


I'm starting to make heavy use of CTEs for my postgres based application, and am wondering if selecting from a previous CTE statement guarantees any ordering?  E.g. is the order of rows for this query guaranteed?  WITH latest_logs AS (     SELECT * FROM logs ORDER BY created DESC LIMIT 100 ) SELECT * FROM latest_logs;   What about this one?  WITH latest_logs AS (     SELECT * FROM logs ORDER BY created DESC LIMIT 100 ) SELECT * FROM latest_logs WHERE my_field = 5;   Or do I always need to re-apply the ORDER BY created DESC every time I select from latest_logs?  Thanks :)


On which site from (Stack Exchange) should someone raise a question?

Let me first describe my experience before raising this question.  On a couple of occasions a question I've raised, or I engaged through a comment or answer on Stack Overflow was suggested to move to another site of Stack Exchange or was actually moved. In one case it was even downvoted for not being on the correct site.  I've tried to find the possible sites of Stack Exchange, and it's not easy. Usually you have to know about, click there and then after the sign in you can see it on the drop menu on top left bar. Notice, that this bar/menu is not available to all sites.  I've also tried to find a topic/thread/page that provides a list, but most importantly describes what is the purpose of each. The best I could come up with, and that was by accident, was the tag  where people ask specifically for the question they have in mind. But they shouldn't in my opinion.  Imagine I want to raise a question, it's my first time to Stack Overflow ecosystem and with Stack Overflow's bulkiness I assume this is the correct space. Yes, there is advice on how to write my question, but there isn't anything about the where should the question be raised. With the voting sometimes providing a feeling of unfair punishment for an easy mistake, the experience of this new user is kind of a bitter one.  Arguably, different sites then it is the problem of the user. But it becomes obvious that it is the same ecosystem. If when creating the account on Stack Overflow, you create it on Stack Exchange as federated authentication. Then, when a moderator can actually move a question from one site to another one, it's even more obvious that it's the same engine powering the each question/comments/answer page.  If I have missed this page then, shouldn't its content be more clear on the "how to ask a question" page? It could be a quick mention that different sites exist with a link to the page that provides the full explanation. For example     If you question is about server automation then use Server Fault   If there isn't a page, then should one be created and made available at key entry points?  Clarification Provided after discussion in comments  It seems that each site has a help center that you find by clicking on the ? icon on the top bar and then select from the drop down menu. There there is a link with title What topics can I ask about here?  For a summary of what each site is intended for, there is an answer on the duplicate question  which provides the information I was looking for.  Thanks for @shadow-wizard and @rene for their contribution to produce this clarification.


How can I replace text after a specific word using sed?

I have a file named .ignore. In need to replace the projdir. For example:  ignore \..* ignore README projdir Snake   I need to replace Snake with, for example, "PacMan". I read the man page, but I have no idea what to do.


My computer shipped with Windows 8 and later I upgraded to Windows 8.1 Right now I'm trying to get Windows 8.1 to dual boot with Ubuntu 12.04, but the Grub menu doesn't show up at all. My computer just boots straight to Windows. I searched for this online and the only answer I get is  to edit /etc/default/grub, but I don't even know what this is and where to find this. I also can't use a bootable CD, only a USB. I really need step-by-step answers that aren't confusing like all the other ones I've found so far.  EDIT: I just rebooted and now the Grub menu does show up but when I try to boot into Ubuntu, it says a file is missing. Windows boots normally though. I have disabled secure boot and fast startup.      Windows failed to start. A recent hardware change or software change might be the cause.     To fix the problem:     1. Insert your Windows installation disc and restart your computer.     2. Choose your language settings, and then click "Next."     3. Click "Repair your computer"     If you do not have this disc, contact your computer administrator or computer manufacturer for assistance.     File: \NST\AutoNeoGrub0.mbr     Status: 0xc000007b     Info: The application or operating system couldn't be loaded because a required file is missing or contains errors.   I'm not sure if that file was corrupted while installing Ubuntu or it's missing.


Is it possible to share 32.768kHz crystal for nRF52 and BNO055? The purpose is reducing cost&space.       Preferred crystal this one:  FC-135R     Also,how can i handle different load capacitance values?(If sharing possible,surely) Other question's accepted answer not satisfy me


I am about to graduate in the Fall and have this summer to try and line something up in terms of a job. I wasn't able to snag an internship even though I am almost done with a computer science degree and was looking to get into the SQA world.  I have no actual industry experience I can put on my resume (only school projects which aren't that impressive - and if they are I dont know why I didn't get reponses). In my last semester I plan to take a Software Engineering course (that will include a lot of topics in SQA) but I was wondering whether I should take some online training course right now that could provide certification that I am able to put on a resume. What are the major industry certifications and do they even help too much when looking for a SQA position in the US? What are the most important tools that employers look for that are used industry wide in SQA (selenium seems pretty popular). Are there any widely known books that everyone knows about that I should study for SQA (ex. for C the K&R book is still very widely used)?


The growing expansion speed of our universe

Is there a definitive way to calculate the speed at which the expansion of our universe is growing? To clarify i don't want to know the speed. I want to know if there is a way to calculate the increase in speed of expansion over time.


Fantasy book set in multiple worlds: main character is looking for his brother in the Amazon

I've been looking for this book for quite some time. It was in English. I remember reading it in high school, around 2005, and the copy I read looked old then, but the name of it is escaping me.  It's about a man in the British army if I'm remembering correctly, searching for his missing brother in the Amazon. He ends up traveling through several different worlds throughout the book. There are only sporadic details that I remember other than that, such as the main character being in a card game on the trip to the Amazon where the other players are cheating and one of the main character's companions having a revolver with a design on the grip.  The method for traveling through worlds was kind of vague. For example he simply passes out after passing through a specific point in the Amazon when the first move takes place.   The one character name I am able to remember is User Annie. She doesn't get introduced until late in the book.


Combinatorial explanation for why $n^2 = {n \choose 2} + {n+1 \choose 2}$

An exercise in the first chapter of Discrete Mathematics, Elementary and Beyond asks for a proof of the following identity:   $$ {n \choose 2} + {n+1 \choose 2} = n^2 $$  The algebraic solution is obvious to me, but less so the combinatorial logic. I think the right-hand side relates to choosing one of n elements twice in a row to produce a set of two elements, including the possibility of duplicate elements (for instance, one could choose the nth element twice in a row). However, given that the sets discussed thus far do contain duplicate elements, it's odd to then interpret n^2 as a representation of such a set. I'm not too sure what the two parts of the left side mean when taken together, either. How can I think about this intuitively based on the combinatorial meanings of the individual terms?


The offset voltage of a saturated transistor, makes bjt less attractive as a switch than mosfet. Why? Is there any other logics aside this?


Continuous {Theorem,Lemma,...} Numbering with cleveref

I want to have continuous numbering for all my theorem, lemma, etc environments, which wan be achieved with using a shared counter.  However this seems to break cleveref's capability of referencing them by distinct names:  \documentclass{book} \usepackage{amsmath, amsthm, mathtools} \theoremstyle{definition} \newtheorem{definition}{Definition} \newtheorem{example}[definition]{Example} \usepackage[capitalise,nameinlink]{cleveref} \crefname{example}{Example}{Examples}  \begin{document} \begin{definition}\label{def} Definition \end{definition}  \begin{example}\label{ex} Example \end{example}  \cref{def}  \cref{ex} \end{document}   This does produce the references Definition 1 and Definition 2, instead of Definition 1 and Example 2.  How can this be circumvented?


Is there an debug equivalent in C# to javascript's console.dir()?

I am using visual studio community 2015. Now when I need some debug info I am using System.Diagnostics.Debug.WriteLine. I would like to know if there is a way to do the same with objects/classes like in javascript's console.dir() For example someObject = { x: 1, y: true, z: "some text"} console.dir(someObject);  give me  I like to get this info to check (for example) parameters that I send to event handlers functions. Thanks


Aligning equations while using cases in align environment

I have the following code:  \begin{align} & a+b+c+d+e+f = 15000 & \text{for } a = 1 ... 15  \\ & D_t=  \begin{cases}    \text{equation} , & \text{for } t = 1 ... 10 \\    \text{another equation} , & \text{for } t = 1 ... 10 \\ \end{cases}  \end{align}   This produces the following:   However, I would like the "for" arguments in cases to be aligned to those in the align environment, which would look something like:    I was wondering if there is a way of doing this automatically, rather than using manual spacing. I have tried using arrays, however it didn't seem to solve the issue.  Thank you.


I have set of linux folders and I need to get the permissions of the folders numerically.  For example in the below directory, I need to what is the permission value of the folder... Whether 755, 644 or 622 etc...  drwxrwsr-x 2 dev    puser 4096 Jul  7  2014 fonts


I've install Ubuntu latest version 14 . now I Have completed with installation. but Have not created disk partition . Pleas guide me how to make Partitions after Installation


How to check specific field is valid or not using jQuery validation plugin?

I am trying to check specific form field is valid or not on button click event but not working.  I have included this jQuery library:     and jQuery code:     HTML Code:  <form name="form" id="form" action="#">
         <input name="brokercat" id="radiobtn" type="radio" name="radio" value="cat05">
My business would benefit from having more cash available.
                  <input name="brokercat" id="radiobtn1" type="radio" name="radio" value="cat04">
My business needs to buy a new piece of equipment.
                  <input name="brokercat" id="radiobtn2" type="radio" name="radio" value="cat02">
My business wants to buy the property that it already
occupies or is looking to move into. Or, I am looking to buy
a business and that includes the premises it occupies.
                  <input name="brokercat" id="radiobtn3" type="radio" name="radio" value="cat06">
I need to acquire a new vehicle for my business.
                  <input name="brokercat" id="radiobtn4" type="radio" name="radio" value="cat07">
I am looking to develop residential or commercial premises.
                  <input name="brokercat" id="radiobtn5" type="radio" name="radio" value="cat08">
I need to borrow for less than 12 months for a property transaction.
                  <input name="brokercat" id="radiobtn6" type="radio" name="radio" value="cat03">
I have outstanding invoices that I would like to use to raise
some extra funding.
                  <input name="brokercat" id="radiobtn7" type="radio" name="radio" value="cat09">
I/we have a pension fund that we would like to consider
using to raise some capital.
                  <input name="brokercat" id="radiobtn8" type="radio" name="radio" value="cat01">
I am looking to buy a property as an investment and to rent
it out.
                  <input name="brokercat" id="radiobtn9" type="radio" name="radio" value="cat10">
My business is looking to help with its overseas trading and
exporting.
                  <input type="button" class="next" value="Next" />
 </form>   I am getting this error:    Any idea why it is not working.  Thanks.


Why is my 7 year old son still having accidents in his pants?

I have an otherwise normal and active 7 year old son who is having trouble going to the bathroom (#2). He is soiling his pants but seems OK with it. He knows it smells bad and he knows it is uncomfortable. He isn't lazy, either. He'd rather hold it in and have an accident than go to the bathroom. He doesn't care if I get upset about it, or if he gets grounded or not. Why is this happening and how can I stop it?


How do I flag a question that should be closed for none of the provided reasons?

So I just came across this question:    And wanted to close it on the grounds that it has absolutely nothing to do with programming. So I click flag->It should be closed for another reason on the basis that the subheading to that options describes the reason:     This question does not meet this site's standards and should be closed.   So then I click off-topic because... underneath which it says     This question does not appear to be about programming within the scope   defined in the help center.   Yup. Perfect. Then I get a list of options, none of which describes the problems with that post:   Questions about general computing hardware and software are off-topic for Stack Overflow unless they directly involve tools used primarily for programming. You may be able to get help on Super User. Nope, the question isn't about general hardware and software Questions concerning problems with code you've written must describe the specific problem — and include valid code to reproduce it — in the question itself. Nope, not about that Questions asking for code must demonstrate a minimal understanding of the problem being solved. Include attempted solutions, why they didn't work, and the expected results. Nope Questions on professional server, networking, or related infrastructure administration are off-topic for Stack Overflow unless they directly involve programming or programming tools. No, unrelated Questions asking us to recommend or find a tool, library or favorite off-site resource are off-topic for Stack Overflow as they tend to attract opinionated answers and spam. No... This question belongs on another site in the Stack Exchange network. Errr... Maybe but do they really want it???   So what am I supposed to do, just send it off to someone on some other Stack Exchange site? Why would this list not be exhaustive?


How to minimize residual sum of squares of an exponential fit?

I have the following data and would like to fit a negative exponential growth model to it:  Days <- c( 1,5,12,16,22,27,36,43) Emissions <- c( 936.76, 1458.68, 1787.23, 1840.04, 1928.97, 1963.63, 1965.37, 1985.71) plot(Days, Emissions) fit <- nls(Emissions ~ a* (1-exp(-b*Days)), start = list(a = 2000, b = 0.55)) curve((y = 1882 * (1 - exp(-0.5108*x))), from = 0, to =45, add = T, col = "green", lwd = 4)   The code is working and a fitting line is plotted. However, the fit is visually not ideal, and the residual sum of squares seems to be quite huge (147073).   How can we improve our fit? Does the data allow a better fit at all?  We could not find a solution to this challenge on the net. Any direct help or linkage to other websites/posts is greatly appreciated.


Setting MediaTek (Ralink) MT7601U USB driver

I have MediaTek (Ralink) MT7601U USB, and with their source, but I am user  anyone can help how to run this USB Wifi?


Why do my SQL Server 2016 transaction logs keep growing?

I'm trying transaction replication for the first time on SQL Server 2016  I have the distribution database on C:\ (I know, but I'm waiting on a new drive), and my bhdb database on D:\.  My problem is that within 6 hours, in spite of the fact the log files started as 1Gb in size, it takes both the C: and D: drives empty space.  How do I stop that from happening?  Thanks.


Texture Channel animated, doesn't appear in viewport

I'm creating an educational video, and for efficiency, I'm using a Cyclic repeater to repeat an on-page/off-page effect.  Every loop, I have the texture channel switch to the next image, rather than duplicating all the objects/animations. This works properly and appears when rendering the animation, but does not appear in the viewport. It sticks to the original UV image that was mapped.  Is there a way to have this change appear in the viewport?


Searched for duplicates but couldn't find any..  Is there any substantial difference between:  var $foo = $(this);   and  var foo = $(this);   ??


How can I prevent syntax higlighting in markdown?

When I wished to show example data, I used the code block syntax (4 spaces indentation after an empty line), but the data was rendered like a programming language. Can I prevent the syntax highlighting?  2013-01-01 1.30 1.35 1236 2013-01-02 1.20 1.37 1237   ...or is there another syntax in markdown?    EDIT:  I the above example, the problem seems not to occur? The original problem, and data   James Bond 01/01/12 200010 03/30/12 -40000 04/30/12 -40000 05/30/12 -40000 06/30/12 -40000 07/30/12 -40000   was here:


How do I save to a file and simultaneously view terminal output?

Linked to this question:  I understand that I can form an output file by using: python3 script.py > output.txt  However, I also want to see the output being generated by the python file while it is being saved to output. Is there a simple way to do this on the command line?


I have a list of items which I want to sort but I can't seems to get the lambda expression right. can someone leads me to the lambda expression? Thanks  unsorted list item:  number: 2, Date: 21/10/2010 11:22:55 number: 1, Date: 21/10/2010 11:22:55 number: 2, Date: 20/10/2010 12:10:00 number: 1, Date: 20/10/2010 12:10:00   sorted list item:  number: 1, Date: 21/10/2010 11:22:55 number: 1, Date: 20/10/2010 12:10:00 number: 2, Date: 21/10/2010 11:22:55 number: 2, Date: 20/10/2010 12:10:00  itemList.sort((x, y) => ...);


kidle_inject uses cpu power without apparent reason

I am using ubuntu 14.04 LTS on an i5-3250M, 6GB RAM Dell Inspiron laptop. I have been noticing all this time from my cpu usage monitor that there is high usage of my CPU (without using something really intensive) and it leads to overheating.  I checked from the system monitor, and at first it seemed like my graphics card was the problem (AMD Radeon 7670M - hybrid graphics with Intel HD 4000). Anyway, I installed fglrx-updates (the only one that actually kind of fixed the overheating problem - fglrx and xorg didn't help) and things ran a bit smoother.  I also installed intel p-state and thermald. Put it on powersave governor, but still no luck. Also installed tlp (no conflict between them).  Tried to see if the fault is from compiz or adobe-flash. No luck. Also, HTML5 uses a LOT of CPU after a bit and it lags everything on my comp.  After doing all of those, I was looking at the results from the $top command and the culprit seems to be kidle_inject. It uses like 50% of the cpu everytime. I couldn't help but notice that it seemed like it had four modules - kidle_inject/0 to kidle_inject/3.  So, what is this kidle_inject? I haven't been able to find something conclusive on the subject. It seems to be on when I use something that is resource intensive and it continues hogging my cpu for a minute or two after terminating usage.  How can I fix this so that my comp is usable at last? I am talking about a minimum temperature of 70C in low-performance use. I am heavily dependent on linux and I would like to keep using ubuntu (since I am used so much to it and I have grown fond of it).  -- I have to say that this is not my machine's fault. When it runs on Windows 7 it's running fantastic with low temperatures.


On Displays I only have 1366x768, but I need 1600x900. I've installed the Nvidia drivers, but still nothing. I've tried using the xrandr --newmode "1600x900", but that doesn't work.  How can I set the resolution to 1600x900?


What kind of Hashing algorithm is my Linux using?

In Kali Linux, I found an unknown hash algorithm used to encrypt the Kali Linux password.  root:$y$j9T$J3nInhusIQkrmvCnX8tlo.$KduXmrDY7wv3o2P/k9t35adUH5XWUBYngo1Wxypy2X.:18749:0:99999:7:::  My Question is: What type of hash is it? It doesn't seem to be MD5 nor SHA-512.


$a ,b , c$ are real numbers such that $ \dfrac1{bc-a^2} + \dfrac1{ca-b^2}+\dfrac1{ab-c^2}=0$ , then how do we prove   (without routine laborious manipulation) that $\dfrac a{(bc-a^2)^2} + \dfrac b{(ca-b^2)^2}+\dfrac c{(ab-c^2)^2}=0$


Does Reduce to Ashes Kill indestructible creatures?

When I first read :     Reduce to Ashes deals 5 damage to target creature. If that creature would die this turn, exile it instead.   I thought "ok, a way to deal with indestructible", but then I thought again and wondered. Because indestructible will stop you dying, and the exile only kicks in after you die.  So does it work?


Show when members are answering questions before deletion

I was recently on Stack Overflow answering a question about why someone's CSS was not working.  The question had only one tag, and may not have been top quality, however I started answering it.  Having spent about 10 minutes constructing an answer explaining the fault was elsewhere, and giving some tips to try and find it, I submitted the answer, only to find the question had been deleted whilst I was answering.  What I would have found useful is a feature that, when viewing the question, and certainly when deleting it, shows how many (if any) users are currently answering the question. Apart from the obvious effort of implementing a Stack Exchange wide real-time tracker for answerer's on both mobile and web, what would be the objections to such a system?


How do I express a degree on my CV that I have completed but have not been awarded?

I have completed all the requirements for an M.S. degree and have filed the appropriate paperwork. All I have left to do is walk at the end of this semester. I want to put this on my CV, but it seems appropriate to differentiate it from my Ph.D., which is (only) "In progress", and another M.S. which I completed a few years ago.   How should I express this on my CV? Should I say "Anticipated" or "Expected", with the date?   My question is different than  because that question asks about a degree that was entirely incomplete, unawarded, and is not likely to ever be awarded. In my situation, the degree needs only to be formally awarded.


How gently could a comet/asteroid/meteorite “hit” Earth?

Could an object from outer-space with the right velocity and orbit come into contact with the surface of our planet in a manner that wouldn't cause it to burn in our atmosphere?


1980's tv series - awakened ancient man with a Phoenix medallion

This was definitely in the realm of sci-fi series: I think title of series had the word Phoenix in it or the main character's powers or power came from a big gold medallion with an illustration of a Phoenix on it. It starts out with a body of an ancient man being dug up by some archaeologist on a dig site. He woke up, but then all I remember is he is always wandering or hitchhiking, kind of like the beginning and ending scene from the Incredible Hulk series in the 80's. One of the characters was a tall weird looking guy with long blonde hair, who drew some kind of power from his Phoenix medallion or something


Is there any benefit to having multiple recruitment radio beacons?

I want to populate my settlements faster, is there any purpose in placing multiple recruitment radio beacons in them?


In my ~/Library folder there is Caches folder. Can this be emptied?

My ~/Library folder has gotten very large. Inside this ~/Library folder is a folder name Caches. This folder 5.5 GB. Can this Caches folder be trashed.


Example 1      I've lived here all my life, and I've been through quakes before. But this one felt different — not because of how big it was, but because of all the bad things that happened before.   Example 2      It was 8:30. My brother had arrived 3 hours before.   Why does the first sentence use past simple and the second use past perfect? I thought with "before" it was not obligatory to use past perfect. Is it because, in the first sentence, there is no logical relation between the bad things and the quakes? That is: the bad things did not cause the quakes.  In the second sentence, both events are compared. Is that why past perfect is used?


need help I screwed my macbook so bad thiere is one drive and no partitions, please read below

So...I somehow messed up my macbook Pro model 1502 raetina 13" Late 2013, core i5, 4GB. I wanted to clean install High Sierra.  Long story short I now have a macbook with one, yes one, there is no base drive, there are no partitions at all.  I can't seem to find anywhere to download an installable version of high sierra anywhere.  Is it possible to make a boot drive from the macos that I can boot with to erase my one drive?  I'm sure there is a lot I don't know nor have thought of.  I greately appreciate any help you can offer


Show that $S_n$ is never isomorphic to a subgroup of $A_{n+1}$ for $n\ge 2$

in my notations, $S_n$ is the symmetric group and $A_{n+1}$ the alternating group.  I showed that if $n$ is even it is never possible because you need to have $n! | n! \cdot\dfrac{n+1}{2}$.   So we need $n$ odd.  I also showed that it is impossible for $n=3$ because $A_4$ has no subgroups of order 6.  Now, for other odd values of  $n\ge 5$, we can use the fact that $A_{n+1}$ is simple, but how to go on from here ?   The links given as duplicate do not provide a clear answer and I am still stuck on this. Here is what I have :  If you consider transposition $(1\quad 2)$, the permutations that commute with this transposition are the ones that fix 1 and 2, and the ones that switch 1 and 2. So that the size of the centralizer of $(1\quad 2)$ is $2(n-2)!$.  Now, because $(1\quad 2)$ is of order 2, it's image must also be an element of order 2 in $A_{n+1}$, so that it must be the product of $2k$ disjoint transpositions. If we now consider the centralizer of the product of $2k$ disjoint transpositions in $A_{n+1}$, we find that a permutation in the centralizer must fix or switch each of the transpositions, leaving $2^{2k}$ choices. Then, we must either pick a permutation of $A_{n+1-2k}$ or $S_{n+1-2k}\setminus A_{n+1-2k}$ to make sure the parity is even. Leaving in total : $$ (n+1-2k)!\cdot 2^{2k-1}$$  Permutations in the centralizer of the product of $2k$ transpositions.  If we had $(n+1-2k)!\cdot 2^{2k-1}< 2(n-1)!$ we would be done, but it is not always true.


Integration of $e^{-\langle Ax , x \rangle}$ over $\mathbb{R}^n$

Problem : If $A_{n \times n}$ is a symmetric, positive-definite matrix, show that : $$\int_{\mathbb{R}^n} e^{-\langle Ax , x \rangle}~ dx = \sqrt{\dfrac{\pi^n}{\det(A)}}$$ where $\langle a , b\rangle$ denotes the inner product of $a$ and $b$.  Approach : I was approaching the problem using the Change of Variable Formula, using the function $\varphi(x) = A^{-1}x$ . Since $A$ is p.d., I can show that it is invertible. But I can't proceed anymore. I found a similar-looking problem , but couldn't understand anything.


loading tocloft makes \ifdefined\chapter TRUE in article class

I am using the article class, and I discovered that the tocloft package defines \chapter, which will mess up with my other stuff. How does this happen? Can I make \chapter "undefined" again after loading tocloft? Here is an MWE:  \documentclass{article} % loading tocloft will make \chapter defined \usepackage{tocloft}  \begin{document}  \ifdefined\chapter    chapter is defined in the current \texttt{article} document.     \chapter{This is not a chapter, but will be typeset as plain text} \else    chapter is \emph{not} defined. \fi  \end{document}


Q: Calculate     $$S=1+{3\over4}+{3\times5\over4\times8}+{3\times5\times7\over4\times8\times12}+\dots$$   I calculated that the $n$th term is given by $$ \begin{align} A_n&={3\times5\times7\times\dots\times(2n+1)\over4\times8\times12\times\dots\times4n}\\ &={{(2n+1)!\over2\times4\times8\dots\times2n}\over4^nn!}\\ &={(2n+1)!\over8^n(n!)^2} \end{align}$$ Hence $$S=\sum_{n=0}^{\infty}{(2n+1)!\over8^n(n!)^2} =\sum_{n=0}^{\infty}{\binom{2n}{n}(2n+1){1\over8^n}}$$  I'm not sure how to proceed  I feel like generating function for $\sum{\binom{2n}{n}(2n+1)}$ would be helpful but don't know how to derieve it.


Difference between using Ubuntu Desktop and Ubuntu Server?

Is there a practical difference between using Ubuntu Desktop and Ubuntu Server?   I am making a VM of Ubuntu Server 14.04 LTS with LXDE desktop, and it's very fast with small size on disk, even after full upgrade. It is a great learning tool, as I am building it from the ground up.  Thank you.


Hard links versus symbolic links: which one is faster / smaller?

Hard links  Given a file original.txt, a hard link hardlink.txt will point to the same inode and continue to exist even when original.txt is deleted.  Symbolic links  Given a file original.txt, a symbolic link symlink.txt will point to the file name.  Question: Which one is faster and which one is smaller?  My intuition says that hard links would be faster, as they are indistinguishable from the original file. However, everything depends on the speed of symbolic links.  Also, which one takes up less hard disk space?  I would like to see answers based on measurements, as questions like  briefly mention size and speed, but do not detail it.


Why do C# collection initializers work this way?

I was looking at C# collection initializers and found the implementation to be very pragmatic but also very unlike anything else in C#  I am able to create code like this:  using System; using System.Collections;  class Program {     static void Main()     {         Test test = new Test { 1, 2, 3 };     } }  class Test : IEnumerable {     public IEnumerator GetEnumerator()     {         throw new NotImplementedException();     }      public void Add(int i) { } }   Since I have satisfied the minimum requirements for the compiler (implemented IEnumerable and a public void Add) this works but obviously has no value.  I was wondering what prevented the C# team from creating a more strict set of requirements?  In other words why, in order for this syntax to compile, does the compiler not require that the type implement ICollection?  That seems more in the spirit of other C# features.


Evaluation of $$\int^{1}_{0}\frac{\ln^2(1+x)}{x}dx$$   $\bf{My\; Try::}$ Let $$I = \int^{1}_{0}\frac{\ln^2(1+x)}{x}dx = \int^{1}_{0}\ln^2(1+x)\cdot\frac{1}{x}dx$$  Using By parts, We get  $$I = \left[\ln^2(1+x)\cdot \ln(x)\right]^{1}_{0}-2\int^{1}_{0}\frac{\ln(1+x)\cdot \ln x}{1+x}dx$$  So we get $$I = -2\int^{1}_{0}\frac{\ln(1+x)\cdot \ln x}{1+x}dx$$  Now how can i solve above Integral , Help required, Thanks


Idea behind proof that $\frac{21n+4}{14n+3}$ is irreducible for all $n$

I have a proof of $\frac{21n+4}{14n+3}$ being an irreducible fraction for any positive integer $n$. The proof starts with the following: Indeed, from the equality: $$2(21n+4)-3(14n+3)=-1$$ and so on..But how does this equality follow from the fraction?


What do the eigenvectors of the Hessian matrix actually represent?

It is known in multivariate calculus that, at a critical point $p_c = (x_{1c}, x_{2c}, ... , x_{nc})$ of the function $f(x_1, x_2, ... , x_n)$, if the Hessian is positive definite we have a local minimum and if it is negative definite we have a local maximum.  However, I'm curious about the eigenvectors of the Hessian.  Do they represent anything useful?  For instance, do they represent an ellipsoid inside of which $f(p_c)$ is the global maximum/minimum?


Weird "hidden answer" in $2\tan(2x)=3\text{cot}(x)$

The question is  Find the solutions to the equation $$2\tan(2x)=3\cot(x) , \space 0<x<180$$  I started by applying the tan double angle formula and recipricoal identity for cot $$2* \frac{2\tan(x)}{1-\tan^2(x)}=\frac{3}{\tan(x)}$$ $$\implies 7\tan^2(x)=3 \therefore x=\tan^{-1}\left(-\sqrt\frac{3}{7} \right)$$ $$x=-33.2,33.2$$ Then by using the quadrants  I was lead to the final solution that $x=33.2,146.8$ however the answer in the book has an additional solution of $x=90$, I understand the reasoning that $\tan(180)=0$ and $\cot(x)$ tends to zero as x tends to 90 however how was this solution found? Is there a process for consistently finding these "hidden answers"?


Please help for parse json response. My json String is     {      "result":[         {            "parent":"",          "made_sla":"true",          "caused_by":"",          "watch_list":"",          "upon_reject":"cancel",          "sys_updated_on":"2019-05-09 15:36:38",          "child_incidents":"0",          "hold_reason":"",          "approval_history":"",          "number":"INC0000060",          "resolved_by":{               "link":"https://dev59401.service-now.com/api/now/v1/table/sys_user/5137153cc611227c000bbd1bd8cd2007",             "value":"5137153cc611227c000bbd1bd8cd2007"          },          "sys_updated_by":"admin",          "opened_by":{               "link":"https://dev59401.service-now.com/api/now/v1/table/sys_user/681ccaf9c0a8016400b98a06818d57c7",             "value":"681ccaf9c0a8016400b98a06818d57c7"          },          "user_input":"",          "sys_created_on":"2016-12-12 15:19:57",          "sys_domain":{               "link":"https://dev59401.service-now.com/api/now/v1/table/sys_user_group/global",             "value":"global"          },          "state":"7",          "sys_created_by":"employee",          "knowledge":"false",          "order":"",          "calendar_stc":"102197",          "closed_at":"2016-12-14 02:46:44",          "cmdb_ci":{               "link":"https://dev59401.service-now.com/api/now/v1/table/cmdb_ci/109562a3c611227500a7b7ff98cc0dc7",             "value":"109562a3c611227500a7b7ff98cc0dc7"          },          "delivery_plan":"",          "impact":"2",          "active":"false",          "work_notes_list":"",          "business_service":{               "link":"https://dev59401.service-now.com/api/now/v1/table/cmdb_ci_service/27d32778c0a8000b00db970eeaa60f16",             "value":"27d32778c0a8000b00db970eeaa60f16"          },


The sum of square roots of non-perfect squares is never integer

My question looks quite obvious, but I'm looking for a strict proof for this:     Why can't the sum of two square roots of non-perfect squares be an integer?   For example: $\sqrt8+\sqrt{15}$ isn't an integer. Well, I know this looks obvious, but I can't prove it...


Sport app, when best to ask to review app

I'm a (proud) owner of a 5 year old running app for iOS & Android. The app is to train both beginners and experienced runners with training schedules (30 lessons in 10 weeks). When do you think it's the best time to ask a user for a review?   After landing on the dashboard X times After completing a run X times and viewing their stats (not my favo)  After completing a training schedule (+/- 10 weeks of running) After viewing total stats / last runs When viewing the achievements   My opinion: After completing 2 weeks of training, after closing my current training and landing on the Dashboard.  And: What 'popup' message would you recommend?  "How is training going with X?" "I am satisfied" / "Can do better".  [EDIT] Why this isn't a duplicate of : The usage of an sport app differs from other apps like games or news related apps. As you actively use the app during your excise you want as little information before, during, and after training. This means a different way of interacting and asking for a review.


Is it possible to accept the alternative hypothesis?

I'm aware of several related questions here (e.g., , ) but I don't know the definitive answer for my question below.  Suppose a hypothesis test where we want to test whether a coin is fair or not. We have two hypotheses:  $H_0: p(head)=0.5$  $H_1: p(head)\neq0.5$  Suppose we use 5% significance level, there are two possible cases:   When we obtain the data and find that the p-value is less than 0.05, we say "With significance level 5%, we reject $H_0$."  p-value is greater than 0.05, then we say "With 5% significance level, we cannot reject $H_0$."   My question is:      In case 1, is it correct to say "we accept $H_1$"?   Intuitively, and from what I have learned in the past, I feel that "accepting" anything as a result of hypothesis testing is always incorrect. On the other hand, in this case, since the union on $H_0$ of $H_1$ covers the whole "space", "reject $H_0$" and "accepting $H_1$" look exactly the same to me. On another thought, I can also think of the following idea, which says it is incorrect to say "we accept $H_1$":     We have an evidence strong enough to believe that $H_0$ is not true, but we may not have an evidence strong enough to believe that $H_1$ is true. Therefore, "rejecting $H_0$" does not automatically imply "accepting $H_1$"   So, what is the right answer?


What is the best way, if any, to downgrade LAS files to an older version?  LAS1.4 works well with ArcGIS 10.3.1, however our clients that are using ArcGIS 10.2.2 or earlier are unable to load LAS1.4 files into an LAS dataset; the file format is undetectable.  Prefer a method in ArcGIS or a free open-source software.  Also, if downgrading the LAS1.4 to LAS1.3 or earlier is even possible, what are the implications of such a process? Will there be an expected degradation of the data itself or certain statistics that are lost?


Find the Values of $p$ and $q$ such that $\int_0^{\infty} x^p\ln(1+x)^q dx$ Converges or Diverges.

The question is to find the value values of $p$ and $q$ such that the improper integral converges or diverges.  My friend indeed found some values of $p$ and $q$ such that it converges, but after many trials, I am still getting divergent for all values.  Via L'Hospital, we have the following:  $$\lim_{x \to 0} x^c\ln(1+x)^q = \infty \space \text{when} \space  c < 0$$ $$\lim_{x \to 0} x^c\ln(1+x)^q = 0 \space \text{when} \space  c > 0$$ $$\lim_{x \to \infty} x^c\ln(1+x)^q = \infty \space \text{when} \space  c > 0$$ $$\lim_{x \to \infty} x^c\ln(1+x)^q = 0 \space \text{when} \space  c < 0$$  Thus, $$\int_1^{\infty} x^p\ln(1+x)^q dx = \int_1^{\infty} x^{p-c}x^c\ln(1+x)^q dx > \int_1^{\infty} x^{p-c} dx$$ which diverges when $p > -1$.  Here, we set $c = \frac{1}{2}(p+1) > 0$.  On the other hand, $$\int_0^1 x^p\ln(1+x)^q dx = \int_0^1 x^{p-c}x^c\ln(1+x)^q dx > \int_0^1 x^{p-c} dx$$ which diverges when $p < -1$.  Here, we set $c = \frac{1}{2}(p+1) < 0$.  Thus, the integral diverges whenever $p \ne –1$.  Then, let $p = -1$.  $$\int_0^{\infty} \frac{1}{x}\ln(1+x)^q dx = \int_0^1 \frac{1}{x}\ln(1+x)^q dx + \int_1^{\infty} \frac{1}{x}\ln(1+x)^q dx $$ $$ \ge \int_0^1 \frac{1}{x+1}\ln(1+x)^q dx + \int_1^{\infty} \frac{1}{x+1}\ln(1+x)^q dx $$  The first summand diverges when $q < -1$ and the second diverges when $q > -1$.  Finally, let $ p = -1$ and $q = -1$.  The integral $\int_0^{\infty} \frac{1}{x\ln(1+x)} dx ≥ \int_0^{\infty} \frac{1}{(x+1)\ln(1+x)} dx$ diverges on both ends.  Did I make a mistake?


Use Canon AE-1 lenses on a Sony Alpha a6000

I have found that my father had an old Canon AE-1 film camera, and I'm about to buy a Sony Alpha a6000 camera. The old AE-1 camera has a good 80mm lens that I'd love to use on my Sony camera, even if all the focus and zooming is manual (I love manual). Is there a chance to have an adapter to use that lens on the Sony.  Cheers!


Convert String to Integer in QGIS tables

I want it to know how to convert string field values to integer values in QGIS Dufour... there are numbers and strings in the same field, when I use toreal(string) it stops and it won´t create the field.


Why is Christian Bale not in the upcoming movie Batman vs Superman?

This is about the upcoming  Zack Snyder movie , where Ben Affleck is playing Batman. I just read an  that Christian Bale wanted to be Batman again. So I wanted to ask why wasn't he cast as Batman in this movie. I checked the Wikipedia entry but nothing suggests why Christian Bale was not there. Nolan is associated with the movie as an adviser and DC Entertainment is producing this one too. So sort of familiar turf, right? But how come Ben Affleck is the new Batman?  EDIT: I would like to add another interesting piece of information. Bale is aged 40 (born 1974) and Affleck is 42 (born 1970). So they have actually cast an older actor.


Consider the following  I have an Html Template object     class HtmlTemplateModel     {        public HTML Html {get;set;}        //..etc     }   and an Html Editor  class HtmlEditorViewModel {    private HtmlTemplateModel htmlTemplateModel;    public HtmlEditor(HtmlTemplateModel htmlTemplateModel)    {       this.htmlTemplateModel = htmlTemplateModel;    } }   This way the TemplateEditor instance applies the changes to the original template since its a reference type, but i dont want to modify its value so i made a new constructor that takes an HtmlTemplateModel and creates a new HtmlTemplateModel.   is this the best way to clone reference type in .NET? and is there a shortcut so that i don't have to create another constructor to clone the object?


I am interested to know about rules in writing abstract in social sciences. Is it wrong if you just cited in the abstract around two key authors of frameworks where your study was based? Then citations were avoided for the rest of the abstract?


Online it says I should be able to find pdfedit in the software center. That doesn't work for me. I've tried many times. Is there any other way to install pdfedit or master pdf edit on ubuntu 12.10.


What can you say about the range space and null space

Let $V$ be a vector space over a field $F$ and $T$ a linear operator on $V$. If $T^2$$=$ $0$, what can you say about the relation of the range of $T$ to the null space of $T$?


Resolving Conflicting Reports on Fermilab $g-2$ Results

Today it was announced that the Fermilab measurements of the muon's gyromagnetic ratio are in disagreement with the Standard Model with a statistical certainty reported at 4.2 sigma [, ], raising the distinct possibility that the discrepancy measured originally at Brookhaven two decades ago is real. On the other hand, a  claims that through state of the art lattice calculations, they have obtained a new theoretical estimate of the muon's $g$-factor which, to my understanding, they claim reduce the discrepancy between theory and previous experiments. From what I have read and understood, it seems to me that (1) the new Fermilab sigma figure is presumably being compared to older theoretical calculations and (2) the new theoretical calculation is presumably being compared to older experimental measurements. This seems rather incredible that these two seemingly conflicting announcements come on the same day. So my question is, what gives? Do the new theoretical calculations (assuming they can be verified) lower the new Fermilab sigma figure?


I have a homework question from my intro to group theory class.   Question:   Find a 4 element abelian subgroup of $S_5$.  Write it's table.  This is where I've gotten so far, but I don't even know if I'm on the right mental track.  We know $S_5 = \{1,2,3,4,5\}$. Abelian means the subgroup of $S_5$ is commutative.   I am having trouble figuring out how to start this.  Do I pick any 4 elements of $S_5$?  Or are there particular elements that must be chosen?  Do I perform permutations on the group first? Or do I chose my 4 elements, and then perform the permutations?  Thank you!


What is the name for the grammatical figure, where the present tense is substituted for a past event?

I am preparing a book for publication which contains the following passage:     Stromberg in Religious Liberalism in Eighteenth-Century England   (1954) noted that 'the critical moment in the emergence of a positive   spirit of reform...consisted in the awareness of evil as being social   and remediable. It begins about 1750.'   My proof reader (my wife) has picked this out suggesting it should be the past tense. However if I say It began about 1750 it seems to convey too much certainty about the exact date. I just want to convey an impression of it being something which emerges in the mid-eighteenth century. I believe use of the present tense is the way to go.   But what is this artifice called, this use of the present to convey mild uncertainty?


Complete Bipartite Graph. Define $K_{mn}$

Let $m, n$ be nonzero natural numbers. Define $K_{mn}$ to be the complete bipartite graph, which has vertex set $V = V_0 \cup V_1$ such that $ |V_0| = m, |V_1| = n, V_0 \cap V_1 = \emptyset$, and edge set consisting of all edges {$a, b$} with $a \in V_0, b \in V_1$.   a) How many edges does $K_{mn}$ have?  b) What is the average degree of $K_{mn}$?  c) For which values of $m, n$ does $K_{mn}$ have an Euler circuit?  Can someone show me how to solve these? For $K_{mn}$ to be the complete bipartite graph.


Dimension of R over Q without cardinality argument.

I am looking for the easiest (elementary) proof that $\mathbb R$ is infinite dimensional as a $\mathbb Q$-vector space, without using cardinality. It should be understandable at highschool level.  So I guess the question could be reformulated as: what is the easiest infinite family of reals that can be showed to be independent ? So far square roots of primes seems a good candidate, but the proof is still a little intricate, is it the easiest possible ?  The goal of this is to show students that we can prove the result by different ways, and see that understanding cardinals is useful. But I still want the students to be able to understand the other proof.


European Etfs following sp500 while European markets are closed

The are ETFS that are traded on the EU stock exchanges that follow the SP500.  My question is if for example at 3pm New York time (when European markets are closed) the Sp500 crashes 15% how this will be reflected to the European Etfs?  I would expect that when the markets open people will sell but until enough people sell for a few hours the ETF will not reflect the index it supposedly follows.  Is this assumption correct? Or will the Etf be adjusted before the opening?  Taking this thinking one step further. One could imagine a scenario that the stocks in the index crash or go up but the Etf does not follow. Is it possible? And if yes then why do we say they follow the index?


Every once in a while we get a question about how to report a bad user to the administrators. Sometimes it's a spammer, sometimes it's a troll, and sometimes it's just someone who had a momentary blip in the "socially acceptable" filter.   But my question is how to report one user. He is always performing to ask the question, he is going to the chat room, he gives all the code and plead to solve his problem. I warned many times, but he is always doing that with other developers.  You can ask me why you are going to report him. Because he didn't work for his project; he always get work from the SO members.  Note: I think he is a junior developer...


Show the OP's name instead of Community when they votes to close

Currently, when the original poster of the question votes to close a question, the close vote is attributed to the Community user, which can lead to confusion on who actually voted to close the question.    Yes, it does say that the question author authorized a pending duplicate vote and whatnot, but that isn't indicated anywhere except for in a hidden thing that most won't look to see.  Like nicael , there really isn't a point to hiding that the question author approved a duplicate vote. Even if they didn't at the most specific level vote to close, it's makes for a better user experience to have something more like this:


\newcommand causes undefined control sequence in section

I am currently writing my CV using a modified version of a LaTeX template from here:   When I list my programming experiences, I formatted the CSharp Symbol using a \newcommand to make it look nicer. The command works, but when used in a section it breaks the building process saying undefined control sequence. When I remove this \Csh command it works again. Whats wrong with the \Csh so that it breaks the formatting of the section?  \newcommand{\Csh}{C{\lserif\#}}   The section in question:  \begin{AbschnittCV}{Something Something}             \EintragCV{Topic1}{                 StuffA: bla bla \newline                 StuffB: bla blubb blubb \newline                 StuffC: blablabla             }             \EintragCV{Programming}{                 \Csh : bla bla \newline                 C/C++: bla bla bla \newline                 Delphi/Java: bla bla bla             }   % <-- This bracket is highlighted as error 'Undefined control sequence. }' \end{AbschnittCV}   How can I resolve this problem/fix my command definition?  The full error log says:      ! Undefined control sequence. \Csh ->C{\lserif                   \#} l.223           }  The control sequence at the end of the top line of your error message was never \def'ed. If you have misspelled it (e.g., `\hobx'), type `I' and the correct spelling (e.g., `I\hbox'). Otherwise just continue, and I'll forget about whatever was undefined.  LaTeX Font Info:    Try loading font information for T1+cmtt on input line 237.  (/usr/share/texmf-dist/tex/latex/base/t1cmtt.fd File: t1cmtt.fd 2014/09/29 v2.5h Standard LaTeX font definitions ) <signatur-bewerber.png, id=62, 108.405pt x 26.499pt> File: signatur-bewerber.png Graphic file (type png) <use signatur-bewerber.png> Package pdftex.def Info: signatur-bewerber.png  used on input line 246. (pdftex.def)             Requested size: 142.26378pt x 34.77982pt.  [3


Bounded sequence and every convergent subsequence converges to L

Let $\{x_n\}$ be a bounded sequence such that every convergent subsequence converges to $L$. Prove that $$\lim_{n\to\infty}x_n = L.$$   The following is my proof. Please let me know what you think.  Prove by contradiction: ($A \wedge  \lnot B$)  Let {$x_n$} be bounded, and every convergent sub-sequence converges to $L$.   Assume that $$\lim_{n\to\infty}x_n\ne L$$  Then there exists an $\epsilon>0$ such that $|x_n - L|\ge \epsilon$ for infinitely many n.   Now, there exists a sub-sequence $\{x_{n_{k}}\}$ such that $|x_{n_{k}} - L| \ge\epsilon$.   By Bolzano-Weierstrass Theorem $x{_{n{_k}}}$ has a convergent subsequence $x_{n_{k{_{l}}}}$ that does not converge to $L$.   $x_{n_{k_{l}}}$ is also a sub-sequence of the original sequence $x_n$, then this is a contradiction since every convergent sub-sequence of $x_n$ converges to $L$.   Hence the assumption is wrong.  So $\lim_{n\to\infty}x_n = L.$


Can I decrypt messages encrypted with AES 128 knowing the cipher text and the plaintext?

I have access to a pair of plaintexts and their corresponding encrypted texts. Would I be able to decrypt a third message encrypted provided they use the same key? From my little understanding of cryptography I cannot get the key but I would be able to get something out of the reusing of the key (by XORing the message and its cipher?).  Thank you very much and I'm sorry if the question is not well-asked, I'm new.


SQL Server log Size increasing while in Simple recovery mode

Is it possible to locate the active transaction, it was not listed in DBCC opentran, the log file keeps getting bigger.   Database is in Simple recovery tried shrinking the database - no luck   Also we have restarted the SQL service, no improvement the log file size keeps increasing.


If $f$ is an automorphism and $|\{a: f(a) = a^{-1}\}| = 3/4 |G|$ then $G$ has an abelian subgroup of index $2$

I edited the question to remove the first part as it is already answered here.  Let $G$ be a finite group and $f$ an automorphism of $G$ and $A = \{a\in G: f(a) = a^{-1}\}$. Prove that if $|A| = 3/4 |G|$ then $G$ has an abelian subgroup of index $2$.   something (very) related. Hints or solutions much appreciated.


Can not access server using Port forwarding

I am trying to access the server from the public ip. for that I have enabled port forwarding on the tp-link router for port 8069.  My pubic is is 123.201.xx.xx   When I try to access my public address with port number, it gives me no response.  I have checked  to resolve the issue. and get to know that my public ip and wan ip is different. i tried to access the server with the wan address and it allows me to access the server locally, not publicly.  my wan address is 100.66.xx.xxx.   what additional configuration i need to do to access server publicly? why my wan address and public ip is different?


I have already bought the PC version on minecraft for my account. However, when attempting to change my skin, the game simply states:"You have to buy the PC edition of Minecraft."   Which is odd because I already have.  Why is this happening? How can I fix it?


Difference between (quantitative,qualitative) vs (discrete,continuous)

Could someone please clarify the difference between these seemingly interchangeable groups? (quantitative,qualitative) vs (discrete,continuous).   Obviously they are not, but I cannot seem to pinpoint the reason why they are different inside my head. I am only a freshman college student so forgive my ignorance.  It would seem that discrete is kind of similar to qualitative, where as continuous is kind of similar to quantitative.  Are (quantitative,qualitative) and (discrete,continuous) just synonyms for each other or is (discrete,continuous) a subset of (quantitative)


Schengen visa refused for the second time

My second Schengen visa application was denied again within two days. I applied with my whole family (mother, sister, grandmother, and me), me and my sister had employment leave letters and all other stuff, but only my mother has ties in our home country, we don't have. The embassy gave the same reason again for the refusal. Please help me. What are the other documents I need to submit?  The information submitted regarding the justification for the purpose and conditions of the intend stay was not reliable.   Your intention to leave territory of the member states before the expiry of the visa could not be ascertained.


add path permenantly on ubuntu for postgresql user

I am having trouble adding current PATH permanently on my ubuntu server for a postgresql user. Every time I ssh or restart the server I have to run export PATH="${PATH}:${HOME}/.local/bin", I am running a python script which will not work unless this command is done so I tried a a simple addition of this in python but it didn't solve. import os cmd ='''export PATH="${PATH}:${HOME}/.local/bin"''' os.system(cmd) ... rest of my code  I also tried sudo export PATH="${PATH}:${HOME}/.local/bin" but it gets removed after each restart what can I do to permanently add this path or make the python script run it.


Hai I have windows  10 alongside Ubuntu 15.04 I have Ubuntu 15.10 update available but if I upgrade Ubuntu to 15.10 then will my windows 10 partition gets deleted ?


When upgrading and creating my new SQL server farm on 2016 I researched things to set on the server, one being MAXDOP setting. From reading up about the setting I have set it at 8 on a server that has 8 logical CPUs.  The server is a VM and I believe it has a single NUMA node.  The worload is OTLP. However I recently went on a training course where the suggestion was to set MAXDOP to 4 so I have started to second guess myself about this setting. CTFP is set at 50. I would appreciate help in determining the correct setting for this.


Prove that for a dense set $A$ and an open set $U$, $U\subset \overline{A\cap U}$

In a topological space $X$ a subset $A$ is called dense if $\overline{A}=X$. Show that for a dense set $A$ and an open set $U$   $U\subset \overline{A\cap U}$  My solution  $U$ is open $\Rightarrow$ $U \subset \overline{U}$  and also $U \subset X$  $\Rightarrow$ $U \subset \overline{U} \cap X $  Since $A$ is dense in $X$ $(\overline{A}=X)$  $\Rightarrow$ $U \subset \overline{U} \cap \overline{A} $  $\Rightarrow$ $U \subset \overline{U \cap A }$  Does this proof looks good or I missed something.


URLs like on a visualstudio.com - advanced routing?

I'm writing here becouse one question doesn't let me sleep calmly. How it's possible that site www.visualstudio.com when I sign in to free TFS account, create special 'part' of site with url {myprojectname}.visualstudio.com?. Is it achieveable in my project using ASP.NET MVC 4 or 5? How it doesn't affect in current DNS system? or it affect? What should I read to let my site be so deeply customizable?  for example:  user1.mysite.xx user2.mysite.xx/aaa/4/sda/something_other


I am a beginner in SEO and I have a website with this structure:  /es/index.php /es/clases.php /es/horarios.php /es/tarifas.php /es/contacto.php /es/login.php  and I have it three times: one for the directory /es/, one for /en/ and another one for /cat/. What I want to do in google is something like this:   I want to index the web by directories like this and all the files which are in it exept login.php. It's possible to do this with the google search console, html and robots.txt?


Every element outside the maximal ideal of a local ring is a unit

A homework question from my algebra class asks:     Show that in a local ring $R$ with maximal ideal $M$, every element outside $M$ is a unit.   My argument is that since $M$ is maximal $R /M $ is a field and so for any $ x \in R \backslash M $, $ x + M $ has a multiplicative inverse, which implies $ x $ is a unit.  I don't see where we need the fact that $R$ is a local ring.


Flagging post cast a close vote from app

When on Stack Overflow (a site where I have question-close permission), there appears to be no option to cast a close vote in the Question Options. I can still flag or cast the vote in the browser as workarounds. When I flagged the post, the main site told me that I had cast a close vote instead, a mismatch from the UI.    Android 4.3


debian : read order of bash session configuration files inconsistent

The three files are read in this order?  .bash_profile .profile .bashrc   This is not happening when I first open a terminal.   I have trace statements in the files appending to the file init.log. Please take a look at the following. It begins after opening a terminal. I have placed a comment to show where the log picks up after the su command.  stephen@debian:~$ cat init.log reading .bashrc done reading .bashrc stephen@debian:~$ su - stephen Password:  stephen@debian:~$ cat init.log reading .bashrc done reading .bashrc # # after su # reading .bash_profile reading .profile reading .bashrc done reading .bashrc done reading .profile done reading .bash_profile stephen@debian:~$    So the su - login triggers the expected sequence however the initial login reads only the bashrc. This cannot be correct. Can someone explain under what conditions this would occur. I could modify the bashrc and profile files so that the initial read includes all expected files but I would rather get to the root of the problem and fix it there.


How do I obtain the "final" standard deviation from a series of values containing individual (also null) SD values?

I have a list of values, say:  AVGprice SDprice count year 10          3      5   1999 20          2      3   2000 30          8      20  2001  40        undef    1   2002   where AVGprice is the average of a certain price and SD its respective standard deviation for that particular year. Count represents the number of occurrences.  What's the best way to calculate the final AVGprice and SDprice for the whole period 1999-2002? For the former, I'd say a weighted average will do, but I am not sure about the final standard deviation - specially because of the undefined value.


The power wire from MacBook Air turns yellow

I noticed that over time, the thin part of the power cord for my Mac Air was turning yellow.  At the beginning I thought that I had spilled some paint or juice, but over time, the area of yellowing became more. I became worried that it might get very hot and the plastic began to melt, but I did not confirm this, since I do not particularly feel its heating. What could be the reason for the yellower wire and should I be worried about this? P.S. If the wire, wipe or wash the yellowness does not go away


When were the 'and' and 'or' alternative tokens introduced in C++?

I've just read this  from Reddit.  They mention and and or being "Alternative Tokens" to && and ||  I was really unaware of these until now. Of course, everybody knows about the , but and and or? Since when? Is this a recent addition to the standard?  I've just checked it with Visual C++ 2008 and it doesn't seem to recognize these as anything other than a syntax error. What's going on?


How far away do you have to be for mobs to spawn

So I have a world in Minecraft PE that only has a tiny island I live on. I want to know how far away do you have to be for mobs to spawn and what light level does it have to be?


Why $O(n)$ has exactly two connected components?

It is well know that $SO(n)$ is connected and $O(n)$ has two connected components: $O^+(n)=\{A\in O(n):\det A=+1\}$ and $O^-(n)=\{A\in O(n):\det A=-1\}$.   In what book can I find this property?


Why can't Ubuntu mount my exfat pen drive?

I format the pen drive in Windows as exfat, but Ubuntu can't mount it.  Which format do I have to use for Ubuntu?


USB devices are not detected in guest OS

I have ubuntu as Guest OS in virtualbox. My host OS is also ubuntu(version 14.10). To do a personal project, I want to detect my android phone in guest OS. By default, Iam unable to see my phone under USB devices. Can someone guide me to find USB devices in my ubuntu guest OS?  Thanks, Deepak


I'm having two oracle databases. A is used for production, B is some kind of staging instance where people are preparing content that is brought to the production system over night. It is a fully working structural clone of A that will also give you a preview of the upcoming next release. While the overnight synchronization is completely automatized (by scripts), structural changes are first applied to B and are two days later applied to A. This depends on manual operations and is build up on sql and sh scripts.  I'm wondering if there are features that lead to better maintainability and can be utilized for manually triggered synchronization. What would be the a modern approach automatizing structural database changes brought from B to A with Oracle Database 11g?  Please excuse this vague question. Since I'm not experienced in this topic I'm looking more for a starting point on what to read than a full solution to my problem.


Representing overlapping lines in ArcGIS Desktop?

I have lots of lines (in one feature class) which share the same location but I want to represent them as lines that are next to each other because they have different properties (different OWNERS).  So, my first try was transforming them in "Cartographic Line Symbol' -> 'Line Properties' set my offset different for each one. Which is fine except:    As you can see when I choose to represent the lines according to their owner (color= owner). The offset works great, but I need all the lines to be connected and sink in a junction. Something like this:    So I tought the solution is to create a representation, but not sure how to use a text field (OWNERS) in order to create those parallel lines (the equivalent of Symbology->Categories-> Unique Values-> Value field: OWNER). I know I should use the offset geometric effect. but I'm not sure if this is the solution and how should I do that.  I am using ArcGIS Desktop 10.1.


Not enough heap memory when resizing images

I created a Java Spring Boot application for a REST product catalog that gets it's info from a remote database where I only have access to a materialized view that rebuilds itself every day. It has a field with large images up to 5 megabytes long.  When I read this view in search for updates, I pass these images to my own system file (register the filename in my own db) but before it, I use Thumbnailator plugin to resize the images in two versions (thumb and fullscreen) with no more than 20 kilobytes each pair.  The problem is that during the process I receive a Java Heap Error:      java.lang.OutOfMemoryError: Java heap space   I tried to fix that using Slice class to paginate the view records (5 records at a time, with a for loop converting 1 file at a time), but no much better results achieved, so I searched a little more and saw this post where I should use -Xmx6g when loading the JAR file, but it is not working either.  It seems that Java VM, Spring Framework, TomCat, (or my code), is not garbaging memory correctly.  I wish to know if there is a standard heap start and max value that could handle regular database and image processing without crashing; or if it is a known bug in one of those parts mentioned above.


Suppose $a>b>0$, compute   $$\int_0^1 \frac{x^b-x^a}{\ln x} dx$$  I tried to use substiution $t=\ln x$, but it didn't simplify the computation. Thank in advance.


Unallocated Space after Live Disk Creation

I have a 16gb flash drive that I used as a live USB. While it was live,  it had a total capacity of 2mb after formatting it,  it still says 2mb.  I viewed the disk in disk management and it showed 14gb of unallocated Space.  How can I recover the space.    Ps. There is no option to extend volume


What exactly is terminal? What is shell?

I know about Linux terminal. I can also issue many advanced commands over terminal. But one simple concept is not clear to me.  What is terminal and how does it work?  I know about hardware which consists of CPU, RAM, HARD DISK and so on.  I know about kernel which is basically the core of the operating system.  I know about software which sits on the top of kernel.  And I know about users.  And I know that user uses either terminal or GUI to give instructions to the software.(or kernel?)  Now please explain these concepts of terminal and shell.  Graphical explanation and simple non-technical words are preferable.


Regular expression for parsing name value pairs

Can someone provide a regular expression for parsing name/value pairs from a string?  The pairs are separated by commas, and the value can optionally be enclosed in quotes.  For example:  AssemblyName=foo.dll,ClassName="SomeClass",Parameters="Some,Parameters"