Proof by induction: $n^{n+1} > (n + 1)^n$, $(1 + x)^n \ge 1 + nx$, other inequalities

I'm struggling around my homework. I hope someone will point me the right direction for solving following examples:   Prove that $n^{n+1} > (n + 1)^n$ for $n > 2$; Prove that $(1 + x)^n \ge 1 + nx$; $x \in\Bbb R$; $n \in\Bbb N$; Prove that $(2n)! < 2^{2n}(n!)^2$; $n \ge 1$; Prove that $2^n > n$:   Thank you a lot.


How to find who changed a table value in SQL Server 2014?

We have a few tables on a database called mydb which is being used by applications to store, or retrieve records. Somehow, someone changed a value on the test table and that caused a serious issue.   We are receiving constant data from different sources, when the data is being updated on the table, a trigger fires and checks for the specific value, if the values is 360 then it will update the rows, else it will do nothing.  Now I have two questions:   I want to know who changed that value 4 days ago?   I dont see any successful login (user login) in the SQL server error log. I assume that someone has used a generic user account named user. Now who used that account to login?     The value on the table is supposed to be 350, but it was changed to 800.   Any tips?


I'm curious how I could control cars in a racing game.  Should my AI agent control its car with commands like "throttle on 0.35, steereing wheel on 0.5 right, brake on 0.0"? Or should I rather pre-compute a curve the car sticks to, and visuals like front wheels turning are just to make everything looks consistent? Or is there any other way?


How to number sections starting from zero? (KOMA-Script)

I use KOMA-Script's scrartcl document class. I'd like the sections of the article to be numbered starting from zero. How can this be achieved? ( claims that KOMA-Script has a built-in feature for this.)


Can I power a device with a power supply that has a higher current rating?

I have a device with an input rating of 23 to 56V DC with a maximum current of 0.5 amperes. Is it possible to supply this device with a power supply with an output rating of 48V DC with 1.0 ampere?


php intval returning something unexpected


Convert 0's to NoData in QGIS Raster Calculator

What is the easiest way to convert cells with a value of 0 to NoData in QGIS Raster Calculator?


iOS 12 tapping on notification to open app not working

I've been looking online and I haven't found any articles about changing this on the new iOS update. Ever since I updated, it has the cool new feature of grouping notifications.   My biggest issue is that I can't tap on an expanded notification to open that app. As in, if I get a text, I can't tap on it to open the messaging app to that text message. I have to either go open the app and then the text or use the mini-preview of the message, but this isn't an option for every app. I have continued to play with the notification settings and I can't find a solution for this. Does anybody have an idea?


I have recently installed lubuntu 11.10 on my old laptop (acer aspire 5315 celeron) and observed that fan is not working properly on lubuntu side.I find it strange that it is working perfectly under window vista.   How could I solve this problem?


Suppose that $G$ is a group with the property that for every choice of elements in $G$, $axb=cxd$ implies $ab=cd$. Prove that $G$ is Abelian. (Middle cancellation implies commutativity).  I am having trouble with this homework problem. The way I started was:  Suppose $G$ is a group for which middle cancellation holds. Multiply $x$ by its inverse, $x^{-1}$ using middle cancellation so you have $ab=cd$. Thus $G$ is Abelian.   I am unsure if this is the way to approach it.


Prove:  $$ 1+\left( 1-\frac{x}{n}\right)+...+\left(1-\frac{x}{n}\right)^{n-1}=\frac{n}{x}\left(1-\left(1-\frac{x}{n}\right)^n\right)$$  The first part could be rewritten as a series such as:   $$\sum_{n=0}^{n-1}\left(1-\frac{x}{n}\right)^n$$  Maybe it could be transform into a Taylor series, but I just don't know where to start.


Assembly code vs Machine code vs Object code?

What is the difference between object code, machine code and assembly code?  Can you give a visual example of their difference?


How to show $\gcd(ac, bd) = \gcd(a,d) * \gcd(b,c)$

Given that $\gcd(a,b) = 1$ and $\gcd(c,d) = 1$, show that $\gcd(ac,bd) = \gcd(a,d) * \gcd(b,c)$.  The work that I have done so far goes as follows.  We write  $$\gcd(ac,bd) = acv + bdu$$ then  $$\gcd(a,d) = ax + dy\quad\text{and}\quad\gcd(b,c) = bs + ct$$ and so \begin{align} \gcd(a,d) * gcd(b,c) &= (ax + dy) * (bs + ct) \\ &= axbs + axct + dybs + dyct \end{align} I tried to factor out some terms, and get $ax(bs+ct) + dy(bs+ct)$  but then I am stuck here. I don't know what else to use to prove the answer.


How to make this .bat script run on background?

I have this script that sets wallpaper every 10 minutes:  SCHTASKS /Create /SC MINUTE /MO 10 /TN MyTaskName /TR "D:/ChangeWallpaper.bat"   the ChangeWallpaper.java:  reg add "HKEY_CURRENT_USER\Control Panel\Desktop" /v Wallpaper /t REG_SZ /d D:\plouzane-1758197.jpg /f RUNDLL32.EXE user32.dll,UpdatePerUserSystemParameters   But each time it runs, terminal windows briefly appears. Is there a way to make it run completely invisibly?


In Landau-Lifshitz - Vol 1. Mechanics, right after the introduction of the principle of leas action, there is the following comment:  It should be mentioned that this formulation ($S = \int\limits_{t_1}^{t^2} L(q, \dot{q}, t) dt$) of the least action is not always valid for the entire path of the system, but only for any sufficiently short segment of the path. The integral for the entire path must have an extremum, but not necessarily a minimum. This fact, however, is of no importance as regards the derivation of the equations of motion, since only the extremum condition is used.    Why is the least action principle not always valid for the entire path? Derivation of the equations of motion requires an extremum, not necessarily a minimum? How do we mathematically check if an extremum is in fact a minimum in this case? What are some physical examples that might give me further insight into this statement?


A different method of evaluating $ \int\frac{1}{\sqrt{\sin^3(x)\cdot\sin(x+\alpha})}\,dx$

I was practicing indefinite integrals and came to this integral:  $$        \int\frac {1}{\sqrt{\sin^3(x)\cdot\sin(x+\alpha})}\,dx. $$  Everywhere there is only one method given for solving this question  which involves dividing numerator and denominator by $\sin^2(x).$  However, I wanted to know if there was any other method for solving this or not?


I have this simple XML: <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE input[ <!ELEMENT input (#PCDATA)> <!ELEMENT file (#PCDATA)> <!ELEMENT name (#PCDATA)> <!ELEMENT type (#PCDATA)> ]> <input> This is the content <file><name>test.png</name><type>Image</type></file> </input>  I expect this to be valid but some online validators report that it is invalid because the input and file elements contain non-text nodes. If I remove the file element within the input element then the resulting XML is reported to be valid, so I expect the "non-text nodes" are the child elements (file in input and name and type in file). I expect this to be valid because the  specifies that an element is valid if it matches one of a set of conditions, one of which is:  The declaration matches Mixed, and the content (after replacing any entity references with their replacement text) consists of character data (including CDATA sections), comments, PIs and child elements whose types match names in the content model.  Note the "and child elements..." towards the end of that. And the production for mixed is:     Mixed      ::=      '(' S? '#PCDATA' (S? '|' S? Name)* S? ')*'               | '(' S? '#PCDATA' S? ')'   The second case is what I have for input and file: (#PCDATA) The validity requirement for mixed content is that there can be child elements as long as their names match names in the content model, which they do. Am I misunderstanding the specification or are these validators incorrect? If I remove the declarations of the file, name and type elements from the DTD but leave the child elements in the content of the input element, then I get additional validation errors indicating no declaration of those types. I expect these errors because the validation requirement is that the child element names match names in the content model and, with those declarations removed, they don't match names in the content model. But there are other validators that report the XML is valid even without the declarations of the file, name and type elements in the DTD. This too seems to be a fault of the validators as the validation requirement clearly says that the child element names must match names in the content model, which they don't, when those element declarations are removed. I know there are various XML validation implementations and they do not all work the same so they cannot all be strictly correct. I am most interested in having a strictly correct understanding of the specification. In strict conformance to the validity requirements of an element with content (#PCDATA):  Can the content of that element include child elements? If so, must the names of those elements match names of elements in the DTD?  The specification only appears to require that the names of child elements match names of elements in the DTD but I think reasonably the content and attributes of such elements should also match the declarations in the DTD, but the specification doesn't actually say this. So, again, in strict conformance with the validity requirements of the specification, must the content and attributes of a child element of an element with content (#PCDATA) match the declarations of these in the DTD? If so, where in the specification does it say so? Finally, is there any easy to use (online or installable to Linux) XML validator that is strictly correct according to the specification that you can recommend?


I've read "JavaScript. The Core by Dmitry Soshnikov" and i don't understand very well this code (refactoring). Why k is increment ?  var data = [];  for (var k = 0; k < 3; k++) {   data[k] = (function () {     console.log(k);   })(k) }  data[0]; data[1]; data[2];   this portion of code :   (function () {     console.log(k); })(k)   So when we add a parameter (k) to the end of a function, if i understand well, the value (k) is take from the current context/scope ?


Is there any solid WYSIWYG editor for Tikz?

I am trying to design a company logo via Tikz and thought an editor would be a huge plus to the task. Are there any good drag and drop (with minimal coding) Tikz editor? Platform is Mac OS X. I am using Sketch but would love to use Tikz.


Dell XPS 13 9343 - keyboard backlight on at boot Ubuntu 15.10

I upgrade from Ubuntu 15.04 to Ubuntu 15.10 and now on the first boot the keyboard backlight is on. I can manually turn it off, but the setting is not remembered and the next boot results in the keyboard backlight being on.  How can I change the behavior to:   Remember the last setting   or   Default to being off?


How to create beautiful (block) diagrams

I would like to include a similar picture in my bachelor's thesis.   I am looking for tips on how to make this (or in general) diagram(s) more beautiful.  Can you recommend programs for creating such diagrams? Preferably free and runs under Linux.


Okay, so my problem is that one of the people I have in my party (my brother) is VERY stubborn when it comes to playing a session of D&D, everything from getting on his tablet and getting distracted to the point where when it's his turn he has no clue what is even happening, saying things like "I punch the monster" when it is 50 feet away from him. I tried to incite a tabletop rule of "No electronics" but everytime I tell him to put his tablet away, he labels me a "Tight-ass DM" and tells me its my fault no one is having fun. What can I do about this? Is he right? Should I make changes to adhere to his rules? I have contemplated removing him from the game, but I really don't want to as he is my brother.


how retain count of NSString type variable is increased?

here is the following program about increasing d retain count value of a NSString type variable in interface part I have declared  @property (strong,nonatomic)NSString *str1; @property (strong, nonatomic)NSString *str2; -(IBAction)goBtn:(id)sender;   and ind implementation part I have defined following  - (IBAction)goBtn:(id)sender {    self.str1=[[NSString alloc]init];    self.str1=self.str2;    self.str2=[self.str1 retain];    self.str2=[[NSString alloc]init];    self.str2=self.str1;    self.str1=[self.str2 retain];    self.str2=[self.str1 retain];    NSLog(@"retain count is %i", self.str1.retainCount);    NSLog(@"retain count of str2 is %i", self.str2.retainCount); }   but the output is  retain count is 0  retain count of str2 is 0  why is this happening?? is there anything wrong in codes???


What is exactly the inverse of the function $f(x)=\frac{x}{1-x^2}$?

How do we find the inverse of the function $f:(-1,1)\to \Bbb R$ by $f(x)=\frac{x}{1-x^2}$?  The problem has been posted  and the answer below says "To show that $f$ has a continuous inverse, you just need to show that $f$ is an open map..."   Is it impossible to find the inverse analytically?


Why principal ideals in Z[x] are not maximal?

Answer: No principal ideal $(f(x))$ is maximal. If $f(x)$ is an integer $ n\ne ±1$, then $(n, x)$ is a bigger ideal that is not the whole ring. If $f(x)$ has positive degree, then take any prime number $p$ that does not divide the leading coefficient of $f(x)$. $(p, f(x))$ is a bigger ideal and it's not the whole ring, since $Z[x]/(p, f(x)) = (Z/pZ)[x]/(f(x))$ is not the zero ring. I have a few questions about the answer. If someone can please clarify, that would be great. Firstly, $(n,x)$ is the ideal generated by a linear combination of $n$ and $x$, is that correct? So that is the set of polynomials having $n$ as coefficients? For the second part, can someone clarify why $(p,f(x))$ is a bigger ideal than $(f(x))$? Namely, this part: $Z[x]/(p, f(x)) = (Z/pZ)[x]/(f(x))$?


Mirrored object doesn't match it perfectly?

Well I retopologized the object and now I am having trouble with the mirror of it. It keeps mirroring int he wrong area and is not matching up equally. Also my verticies at the end of my mesh that would connect the mirror are not alligned properly. Can someonehelp. I have pictures below.


How do I restore default owner of files in /var/ directory?

Accidentally in /var/ directory I ran chown root . -R;chgrp root . -R. Now services like mysql don't start. Is there a way to restore default owner and groups?  If there is no way, what is the default owner and group of /var/lib/mysql directory and it's files?


I installed Kubuntu 12.04 on this desktop last September and am the main user of the machine. I can perform most admin tasks such as installing new software with my password, which is also accepted using sudo in a terminal. Some tasks however ask for a root password - the most recent example being when I tried to re-install my HP printer. and my usual password does not work. I have looked at  answer, but it doesn't seem to help as I know my own password. I need to know root's password!


Can summons and eidolons be magically healed?

This is a two part question.   Can summons benefit from ? Can  benefit from magical healing? This question treats normal and unchained summoners as equal unless there is a specific difference where it concerns healing.   I have looked at the  spell and it does not say that the monster summoned actually exists (for instance the eidolon specifically states that its an aspect of the creature and not the creature itself) or if its an aspect of a greater creature.  Reading cure light wounds it talks about what happens with living and undead, but nothing else is mentioned.


How to determine if .NET code is running in an ASP.NET process?

I have an instance of a general purpose class that will be executed both under ASP.NET and a stand alone program. This code is sensative to the process where it is being run - that is, there are certin methods that should not called if running under ASP.NET. How do you determine if the code is executing in an ASP.NET process?  The solution I am currently using is answered below.    I wish someone would add a comment as to why this question has gotten downvoted and/or propose a better way to ask it! I can only assume at least some folks have looked at the question and said "what an idiot, ASP.NET code is .NET code".


I run ubuntu on my laptop from an external drive.  But I turned it off yesterday, and when I tried to turn it back on, this message came up:  error: file '/boot/grub/i386-pc/extcmd.mod' not found. Entering rescue mode... grub rescue>'   I don't know what to do, can someone please help me?


Deriving the limit formula of second derivatives

I tried to derive the formula second derivatives from Wikipedia:     $$f''\left( x\right) =\lim _{h\rightarrow 0}\dfrac {f\left( x+h\right) -2f\left( x\right) +f\left( x-h\right) }{h^{2}}$$   Let $y=f(u)$ and using first principles, since $$\dfrac {dy}{du}=\lim _{k\rightarrow 0}\dfrac {f\left( u+k\right) -f\left( u\right) }{k}$$ therefore, $$\dfrac {d^{2}y}{dx^{2}}=\dfrac {d\left( \dfrac {dy}{du}\right) }{dx}= \lim _{h\rightarrow 0} \dfrac{\left.\dfrac {dy}{du}\right|_{u= x+h}-\left.\dfrac {dy}{du}\right|_{u=x}}{h}\\ = \lim _{h\rightarrow 0}\dfrac {\lim _{k\rightarrow 0}\dfrac {f\left( x+h+k\right) -f\left( x+h\right) }{k}-\lim _{k\rightarrow 0}\dfrac {f\left( x+k\right) -f\left( x\right) }{k}}{h} \\ = \lim _{h\rightarrow 0}\dfrac {\lim _{k\rightarrow 0}\dfrac {f\left( x+h+k\right) -f\left( x+h\right) -f\left( x+k\right) +f\left( x\right) }{k}}{h} $$ And I’m stuck with a stacked limit of two bound variables. So what have I done wrong?


What is the best practice to have a column header alignment, should it be left or center aligned? On click of the column header the columns can be also sorted. Numeric values will be right aligned by default.


What is the trick to soldering to aluminum bases (like are found on the older Luxeon LEDS?)


An irrational number $x$ such that $x^x$ is rational

I can show that there exists an irational number $x$ such that $x^x$ is rational. But I have no example. Can you give a pricise example of such number $x$?


How do I reset and restore an Ubuntu without the password

I was recently given a asus laptop with Ubuntu in it but they cans remember the password and I can’t do anything on it.


Here's some code for example  class A {   int i; }  void main() {   A a; }   Is there any possible (probably hackish) way to access a::i in main?  Edit: a::i is supposed to stay private.


Does an increasing sequence of reals converge if the difference of consecutive terms approaches zero?

If $a_n$ is a sequence such that   $$a_1 \leq a_2 \leq a_3 \leq \dotsb$$   and has the property that $a_{n+1}-a_n \to 0$, then can we conclude that $a_n$ is convergent?   I know that without the condition that the sequence is increasing, this is not true, as we could consider the sequence given in  to a similar question that does not require the sequence to be increasing.  $$0, 1, \frac12, 0, \frac13, \frac23, 1, \frac34, \frac12, \frac14, 0, \frac15, \frac25, \frac35, \frac45, 1, \dotsc$$  This oscillates between $0$ and $1$, while the difference of consecutive terms approaches $0$ since the difference is always of the form $\pm\frac1m$ and $m$ increases the further we go in this sequence.    So how can we use the condition that $a_n$ is increasing to show that $a_n$ must converge?  Or is this still not sufficient?


How I can send a simple mail from Ubuntu command line without giving the password for the email account which I'm sending to?


When is the 1st sign that Harry shows any affection for Ginny?

So any of ya'll that don't know      Harry marries Ginny   But I was wondering what was the 1st sign that Harry showed feelings for Ginny.


How to move all file with specific extension from all subfolder into a single target folder?

I've restored an old hard disk using photorec. So I've a lot of file of different kinds under about 400 folders. I'd like to, for example, move all jpg file into /restore_by_type/jpg I'm on windows 10 pro x64bit, insider preview


Number of solutions to $89 x \equiv 7 \pmod{55}$

How do I show that my solution to the congruence is the only solution? I'm asked to solve, $\mu,\lambda$ that satisfy $$89 \lambda+55 \mu=1$$ Using Euclid's algorithm I found $\lambda=-21,\mu=34$. Then I'm asked to find the solution to $$89 x \equiv 7\pmod{55}$$ Using $\lambda 89 \equiv1 \pmod{55}$ I found that $7\lambda89 \equiv7 \pmod{55} \implies x=7\lambda +55k$ for $k\in \mathbb{Z}$. But how do I show, that this is the only solution to the congruence?


for below Variable output need a regex or linux and windows command to display only specific text which is after 'host' and before 'is'

KVM05786Y: The Communication host ADMK05786HTREDIRECT_JA3A is SUCESS KVM05786Y: The Communication host KOPYUTRCEPORT_JA3A is SUCESS KVM05786Y: The Communication host ADMK05786HTSRM_JA3A is SUCESS KVM05786Y: The Communication host ADMK05786HTIAS_JA3A is SUCESS KVM05786Y: Communication host ADMK05786HTOTN_JA3A is SUCESS KVM05786Y: Communication host ADMK05786HTWPM is SUCESS KVM05786Y: The Communication host OCAIDEKD_JA3A is SUCESS KVM05786Y: The Communication host ADMK05786HTSC_JA3A is SUCESS Tried as below  name: "Get data" shell: cat /var/tmp/http_data.txt register: key_data  set_fact: service_name: "{{ service_name | default([]) + [item|regex_search( 'The Communication host\s+"(\S+)"\s+is SUCESS.*','\1' )] }}" with_items: "{{ key_data.stdout_lines }}"


European traveler driving a rental car across Canada/US border and back

I'm a citizen of an EU member state traveling to a small city in Vermont. Looking at flight data, it seems that it would be quite a bit quicker to fly into Montreal (Canada) and then drive a rental car to my final destination in Vermont (and back), rather than getting a connecting flight into a small local US airport. I am slightly worried about the trouble I might get myself into by crossing a land border twice, though.  Can anyone give me an idea of what I'd be getting into in terms of:   Crossing time Discomfort Additional paperwork required   For both the outbound (Canada/US) and the return leg (US/Canada) of my journey, when compared to crossing the border at an international airport?  Also, do I need to take any special actions when I'm arranging a rental car if I intend to drive it over to the US and back?


How to pronounce "slash" in giving an address, meaning the corner of 2 streets?  I live at 1/9 Park Lane. Should it be read as one slash nine Park Lane?


Torrent size taking more space on the HDD

I have downloaded multiple files that have 500GB in total but my 1 TB hard drive is already full. What is happening?


How to force GPG to use console-mode pinentry to prompt for passwords?

Using gpg from a console-based environment such as ssh sessions fails because the GTK pinentry dialog cannot be shown in a SSH session.  I tried unset DISPLAY but it did not help. The GPG command line options do not include a switch for forcing the pinentry to console-mode.  Older GPG versions offered a text-based prompt that worked fine in SSH sessions but after the upgrade it just fails.  There is the --textmode command line switch but apparently, it does something else.  What would be the proper and clean way of getting plain-text pin entry for remote sessions?


Does partitioning iTunes and iPhoto libraries make my Mac faster?

I have a   iMac (early 2009)  with    2,66 GHz Intel Core 2 Duo   4 GB 1067 MHz DDR3   640GB 7200-rpm Serial ATA hard drive  If I create a partition for the iTunes library and another one for the iPhoto library (they are pretty heavy), do you think this makes my Mac faster or not? And, if possible, can you shortly explain why?  Thanks!


integration of a periodic function by substitution

Given a periodic function $f$ with period $L$ I want to prove the following:  $$\int_a^{a+L}f(x) \,dx=\int_0^Lf(x)\,dx$$  I've found some nice proofs  but I have tried by my own doing the following:  $$\begin{align*}\int_a^{a+L}f(x)dx&=\int_a^Lf(x)dx+\int_L^{a+L}f(x)dx\\ &=\int_a^Lf(x)dx+\int_0^af(y)dy\\ &=\int_0^Lf(x)dx \end{align*}$$  by using the substitution $y=x-L$.  So I was wondering if this is enough? Because all the proofs there say that this only holds for $a\in[0,L)$ but not for $a$ in general.  So my question is why is this not enough and only holds for $a\in[0,L)$ but not $a$ in general?


Can I configure the Unity launcher to appear on both of my monitors?

I would like to have the Unity launcher appear on both of my monitors. If the launchers could be configured to show only the windows active on their respective monitors, that would be even better.  How would I go about doing this?


In a comment on this , someone said that they weren't sure what functools.wraps was doing. So, I'm asking this question so that there will be a record of it on StackOverflow for future reference: what does functools.wraps do, exactly?


Rotation of an angle that has another as the center

"With a 2 dimensional surface: We take (2, 1) as the center point and consider a transformation with a rotation angle of 45◦ so point (3, 3) is transformed into point ...?"  I'm really close to getting the answer! I've gotten (-1/sqrt2,3/sqrt2) but the answer is (2-1/sqrt2, 3+1/sqrt2). Please tell me what I'm missing.  Thank you!


How do I get notified of _all_ package updates?

Is there a mailing list and/or IRC channel that announces changes to packages hosted by the Canonical repositories? If so, how does one subscribe? Here's an update explaining how this question is different from those linked as possible duplicates: I'm interested in subscribing to all changes in all packages throughout a given repository-suite tuple. Some editors/commenters have shown how to subscribe to events relevant to a single package, but the technique relies on setting up , either via browser extension or cronjob-python-script. This technique has a number of shortcomings that make it unsuitable for what I want:  it polls rather than subscribes; i.e., polling too fast wastes bandwidth and polling too infrequently risks losing information it's too manual; i.e., it requires a human subscriber to add the things being monitored it's too shallow; i.e., it does not track or accumulate changes through time  To those asking "Why?", let me explain my motivation by way of example. Consider an automated nightly build process that, without any change to the package being built, suddenly starts failing. Clearly, something in the Build-Depends and/or Depends has changed to cause the failure. One can bound the duration between the most recent success and the failure that follows it. What happened to the package repositories within that duration?


IE 8 doesn't open certain website, firefox does

OS: Windows XP SP3. When I try to open the website brokerkf.ru in IE8, it says, that it can't find the server. While it opens google.com and many other websites.  Firefox and Chrome open brokerkf.ru without any problems. nslookup  shows the website IP address correctly in the command prompt.  This domain is not in /etc/hosts file.  What could be the issue? I am puzzled.


Do phrases like "the 80s" take singular or plural subject-verb agreement?

Which is correct:   The 80s is returning The 80s are returning.   If you say "are returning", then why do we say, "The 80s was a time of....." ?


I have a small question regarding using sudo with output redirect >. To enable IP forwrding, someone can use the command:  echo 1 > /proc/sys/net/ipv4/ip_forward   Executing this command will give permission denied as it requires root privileges. However, executing the same command with sudo gives also permission denied error! It seems that output redirect > does not inherit the permissions of the preceding command echo. Is this right?  As a workaround I do:  echo 1 | sudo tee /proc/sys/net/ipv4/ip_forward   Is this the best way to do it? Am I missing something?  Please, note that this is an example and it applies to all commands that use output redirect.


Convergence of the sequence $a_n=\int_0^1{nx^{n-1}\over 1+x}dx$

How to prove the following sequence converges to $0.5$ ? $$a_n=\int_0^1{nx^{n-1}\over 1+x}dx$$ What I have tried: I calculated the integral $$a_n=1-n\left(-1\right)^n\left[\ln2-\sum_{i=1}^n {\left(-1\right)^{i+1}\over i}\right]$$ I also noticed ${1\over2}<a_n<1$ $\forall n \in \mathbb{N}$.  Then I wrote a C program and verified that $a_n\to 0.5$ (I didn't know the answer before) by calculating $a_n$ upto $n=9990002$ (starting from $n=2$ and each time increasing $n$ by $10^4$). I can't think of how to prove $\{a_n\}$ is monotone decreasing, which is clear from direct calculation.


Copy data from one table to another and change id

I want to copy one row from one table to another table. But in the process I want change value of id. For example to 20. How to do it?  I have this code  INSERT INTO work_done SELECT * FROM work_todo WHERE id = 10


Why do I get a reboot instead of a shutdown?

After two days of installation, strangely my Ubuntu machine is restarting instead of shutdown from both desktop GUI and command line.  sudo shutdown -h now sudo halt  # (doesn't shutdown, instead freezes on boot screen Plymouth)   I had force shutdown by powering off the machine.  This is not happening all the times.  I have been using Ubuntu for 6 months and never experienced this kind of problem.


Say, for example, I eat a very spicy jalapeno and I have a burning sensation in my mouth and throat.  Are there any foods or drinks to wash that away?


What symbol for primitive recursive cutoff minus?

I am using $\overset{.}{-}$ for the primitive recursive function between natural numbers such that $m\overset{.}{-}n$ is m minus n if m>=n and otherwise 0. Is there a better and more canonical alternative for a mathematical text?


Explanation of $A \to B = \neg A \lor B$

Can anybody explain intuitively why the logical implication $A \to B$ is equivalent to $$ \neg A \lor B$$   ?  If e.g. $A$  is "It rains." and $B$ is "The street is wet.", then obviously $A$ implies $B$. Why is this the same as "It doesn't rain or the street is wet."?


I have recently acquired a used Nikon D3000 and I've noticed its lcd has dark corners. Seems to have a spotlight in the center of the lcd though it's not affecting the actual image when opened in laptop. I just want to know what's causing this as this might be an issue that can affect other parts of the unit in the future. I've aso looked around the settings for possible configuration but can't find any and also can't find a related thread over the internet.  Please see pic below.


Closed form for the sequence defined by $a_0=1$ and $a_{n+1} = a_n + a_n^{-1}$

Today, we had a math class, where we had to show, that $a_{100} > 14$ for  $$a_0 = 1;\qquad a_{n+1} = a_n + a_n^{-1}$$  Apart from this task, I asked myself: Is there a closed form for this sequence? Since I didn't find an answer by myself, can somebody tell me, whether such a closed form exists, and if yes what it is?


Adjust timeperiod for background scanning?

is it possible to adjust the automatic background scanning timeperiod? I want to decrease the time period.  Thanks.


I need to do a join with a table/result-set/whatever that has the integers n to m inclusive. Is there a trivial way to get that without just building the table?  (BTW what would that type of construct be called, a "Meta query"?)  m-n is bounded to something reasonable ( < 1000's)


Is it possible to search for posts where the OP self-answered?

Looking at , I don't see any shortcuts for searching questions where the OP self-answered.  I'm trying to search specifically where the OP added details to the original question by adding an answer rather than editing the original post. Admittedly, these get flagged pretty early, but occasionally, they get missed.  But I think there should be a way to do this.  Is it possible to search for posts where the asker of a question has also answered the question?


error with (sudo apt-get update ) in ubuntu 20.04

that is the error wich appear when i try to update  E: The repository ' focal Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.


LED lights with a dim light in open circuit

I was installing new LED lamps on my kitchen, which seemed to be functioning well. After turning off the lights, the newly installed lamps still had a dim light, that kept itself for quite long.  I've measured around 60VAC on the OFF switch for these lamps and 110VAC for the OFF switch attached to another lamp.  After lots of head scratching, I've tried to plug just one leg of the LED lamp into a plug hole, result on the picture below.     Why does this happen? How can I prevent it? Does it take a toll on my electrical bill?


Ubuntu 17.04 freezing completely at random intervals

I have an Ubuntu 17.04 instance that randomly locks up. Nothing responds so I have to turn off the PC using the power button.   I've realised that the issue starts when I try to reboot my computer... Sometimes the wifi stops working for like 15 seconds and then asks me for the wifi password.


Keeping shirts crease free when commuting

I'm a manager in an office and need to wear shirt and tie every day.  I am also a keen commuter cyclist (5 mi cycle to station, train, 0.5 mi walk to office).  I've tried panniers, rucksack, rolling shirts up, trying to keep flat and folded...but as yet I still end up with more creases than I'd like.  Any advice on how to keep my shirts as crease free as possible?  (Oddly enough, my trousers always seem to come out nicely!)


Recommended reverse firewall applications for linux?

I'm looking for a reverse firewall, something like  for Linux, but my google-fu is failing me. Does something like this exist on Linux?


Can't see added cube on my scene collection

When I select add and then cylinder, cube or whatever, then I can't see the cube on my collection side menu on the right.    I want to do some booleans from the air intake seen in screenshot 2. That's why I need to be able to select the cube and the object I'm modeling. But if I can't select the cube, I can't do it that way.


Please consider the following sentences:   I worked in China last year.= simple past I was working in China last year.=past continuous.   As I understand it, the simple past is used to describe an action that started and ended at specific times. Since it started at point A and ended at point Z then isn't the intervening time between A and Z continuous? In which case, how would a learner know which of the two sentences to use since they both appear to serve the same function.  I've noticed that some books, including Michael Swann's Practical English usage book, suggest that simple past is used to indicate a short duration whereas a continuous form is used to imply a longer period of time. I personally cant see this.  Any thoughts?


How do I know which version of Minecraft I have?

I don't know which version of Minecraft I have. I have regular Minecraft, not Java or anything else and I just don't know the version I have.


How do I turn the little emission sphere into a realistic flaring sun. (This piece is animated with all the planets rotating and revolving)


I have Desktop with ubuntu Linux installed. I don't have Internet Connection at home. I download Linux base application on USB Drive. How I can install those application in Ubuntu. Help or guide me to install softwarae


Verifying that a certain collection of intervals of $\mathbb R$ forms a topology

I'm doing exercise from "Topology without tears book", page 27, exercises a and b.   First one (a) reads as follows. "Let $\mathbb{R}$ be the set of all real numbers. Prove that each of the following collections of subsets of $\mathbb{R}$ is a topology.  a. $\tau_1$ consists of $\mathbb{R}$ , $\emptyset$ and every interval $(-n;n)$ for $n$ any positive integer  b. $\tau_1$ consists of $\mathbb{R}$ , $\emptyset$ and every interval $[-n;n]$ for $n$ any positive integer"  To prove this I noticied that     $S_n=(-n;n) \in \tau_1 \; \forall n \in \mathbb{N}$ by definition.   $S_{n_1} \subset S_{n_2} \; \forall \; n_1 < n_2, n_1,\;n_2 \in \mathbb{N}$   From 2 it follows that    $S_{n_1} \cap S_{n_2} = S_{n_1} \; \forall n_1 < n_2 $  $\bigcup_{i=1}^{i=n} S_i = S_n \in S_{n+1} $   Sience intersection of any two sets is in $\tau_1$ and union of any number of sets is also in $\tau_1$ and noticing that $S_n \subset \mathbb{R} \; \forall n \in \mathbb{N}$ I can state that $\tau_1$ is a topology of $\mathbb{R}$  Is this proven right? I have the following question. Exercise b is very similar to exercise a - the only difference is that now $[-n; n]$ is a closed interval. I think that I still can use the same prove for this case too, but not sure - does closed interval $[-n;n]$ changes anything?


Why is the nontrivial left ideal of $M_ 2(D)$ minimal?

I'm totally confused by this question. I appreciate any help or answer. thanks in advance why is the nontrivial left ideal of M_2(D) minimal? that D is a division ring


The new rep handling needs some noise-cancelling hysteresis

The  is great, but  the fact that each change shows up makes the rep display a bit confusing and rather "noisy."  Apparently, users constantly accept, then unaccept, then accept answers — usually doing all three within seconds of each other. Similarly people upvote, then un-upvote, then re-upvote again, within seconds. See the image below.  As engineers, we know that the usual response to this kind of noise is to throw a bit of  into the system, as when debouncing the input from a keystroke or mouse click.  I suggest that events on the same object (question or answer) within, say, a minute of each other that cancel each other out should be filtered out of the display. So referring to the image below, rather than  +30 41 mins ago  accept    Select all input tag in without certain attribute in Jquery -15 41 mins ago  unaccept  Select all input tag in without certain attribute in Jquery  ...we'd just see  +15 41 mins ago  accept    Select all input tag in without certain attribute in Jquery  ...as we used to.


For 1 specific citation (and only for that one) with many authors, biblatex keeps on using "author1, author2, et al" even though for everything else it is correctly using only 1 author when there are more than 2 authors (i.e. "author1, et al")  edit: So I've found the culprit. I have two citations with the same first author, and biblatex isn't liking it. Since the publications are on different years though, I'm not sure why this is causing an issue.  MWE:   \documentclass[letterpaper, 10pt]{article} % Using BIBER \usepackage[backend=biber,sorting=nyt,style=authoryear,maxnames=2]{biblatex} \usepackage{placeins} \addbibresource{bibblio.bib} \renewcommand{\bibfont}{\small} \begin{document} I want to cite \cite{hutter2012starleth} and \cite{hutter2010slip}. \printbibliography \end{document}   And the bib file is:  @book{hutter2012starleth,   title={StarlETH: A compliant quadrupedal robot for fast, efficient, and versatile locomotion},   author={Hutter, Marco and Gehring, Michael and Bloesch, Michael and Mark, A Hoepflinger and Remy, C David and Siegwart, Roland Yves},   year={2012},   publisher={World Scientific} }  @inproceedings{hutter2010slip,   title={Slip running with an articulated robotic leg},   author={Hutter, Marco and Remy, C David and Hopflinger, MA and Siegwart, Roland},   booktitle={Intelligent Robots and Systems (IROS), 2010 IEEE/RSJ International Conference on},   pages={4934--4939},   year={2010},   organization={IEEE} }


How does a load-balancer manages end user http sessions?

I would like to know, How HttpSession works on Load balancer? How Load balancer knows for the particular request need to send the respective Web Server?  Here's what I would guess:  1. load-balancer works based on user's region like county, state.  2. load-balancer works based on user IP address range  3. load-balancer works based on Cookies management.


Centering \vdots in a system of many equations

I have a system of equations with an arbitrary number of equations (k). I'd like to use \vdots to compactly describe the system, like so:  \begin{align*}   R(-1) &= \sum_{i=1}^m A(i)R(i-1) \\   R(-2) &= \sum_{i=1}^m A(i)R(i-2) \\         &\vdots                    \\   R(-k) &= \sum_{i=1}^m A(i)R(i-k) \end{align*}     I'd like the dots, however, to be centered with = or the entire equation. Is there an elegant way of centering a column or row with AMSMath? I'm currently using an unholy combination of whitespace operators (\; \, etc.) to get the job done.


Analytical formula for the variance of ARMA(2,1) model

I'm looking for methods to derive an analytical formula for the variance of an ARMA(2,1) model.  Given $$(1-\phi_1B-\phi_2B^2)Z_t=(1-\theta_1B)a_t, $$  I've tried the usual "trick" $$\text{Var}[Z_t]=\text{E}[Z_t(\phi_1Z_{t-1}+\phi_2Z_{t-2} + a_t - \theta_1a_{t-1})], $$ which naturally gives me a relationship between the variance and the covariances $$\text{Var}[Z_t]=\gamma_0 \sim \gamma_1 + \gamma_2 + \text{const.}$$  I've tried solving this recursive relationship for $\gamma_0$ by generalizing the relationship to e.g. $$\gamma_k \sim \gamma_{k+1} + \gamma_{k+2} + \text{const.},$$ and writing out formulas for $k=\pm1$. But this introduces another unknown covariance $\gamma_3$.    I've also tried to expand $Z_t$ down to a known time value, say $t_0$. But this approach creates a messy formula, which I'm not able to evaluate for the variance.  Are there any other approaches that results in an analytical formula for the variance of an ARMA(2,1) model?


Capture the specfic text and replace it in C#

Below is the example -   I'm going to ??Location??. I will go to ??Location_New??  In these string values I need to capture the text surrounded by ?? mark. I can replace it if the values within the ?? mark is static using contains method. However it is not but I need to capture the text. So can you someone guide me on this.  Application purpose is, It should capture any values surrounded by ?? mark and prompt to user then user will enter the value that should replace the text surrounded by ?? mark. Not just one text value only. All the text surrounded with ?? mark


How to show XYZ coordinates without the 'Fn' key?

My keyboard doesn't have an Fn key so I can't get the coordinates to show up. I don't know how to get into the multiplayer settings and Shift + F3 doesn't work either.  How can I fix this?


Ten minutes have passed. Let's wait five more.   Is using have here correct?


system.out.println output for decimal numbers

I am trying to understand below output  System.out.println(4.0-3.2);   output is 0.7999999999999998  while it was expected to be  0.8  on the other hand   System.out.println(4.0+3.2);   is 7.2   System.out.println(2.0*0.2);   returns 0.4 why is so long value in case of System.out.println(4.0-3.2);  Can you please explain?


Do close votes on old questions really ever age away?

So now and then I stumble upon an older question which is essentially a duplicate of a yet older and/or more popular/canonical question. Today's example is  which is the nth duplicate of .   However, I can't vote for close because of a close vote I've already cast five years ago.     You voted to close this question Aug 28 '11 at 13:26   Based on those related meta questions  and  they should have aged away long ago.  This is not the first time I'm seeing this. It seems that aging of close votes doesn't work very well for "very old" questions. At least, I don't remember seeing above message on a question posted after about 2012.


Ctrl + shift is not working on Ubuntu 20.04

Today I upgraded my Ubuntu to 20.04 version and noticed that shortcuts commands using Ctrl and Shift buttons are not working. It not depends on selected language, it's just ignores Ctrl. How can I fix that?


Solve system of equations with no constant terms

I am trying to balance a chemical equation algebraically and have found the resulting system of equations:  $$\begin{align*}     3a+8b+d&=12e+4f+2g\\     a&=e\\     4a+4c+3d&=4e+3f+g+3h\\     2b+d&=3e+f\\     c&=h \end{align*}$$ I am able to reduce this to a system of three equations: $$\begin{align*}     8b+d&=9e+4f+2g\\     c+3d&=3f+g\\     2b+d&=3e+f \end{align*}$$ Now, I recognize that there are more variables than there are equations, and so there is no single solution to this equation. However, I need a solution with reasonably low numbers and only integer values for all the variables ($a,b,c,d,e,f,g,h$ or, by substitution, $b,c,d,e,f,g$). A matrix solution won't work since (in standard $AX=B$ form) the only elements in $B$ are zero and therefore all the variables are zero.  As a side note, the reaction is: $$H_3PO_4 + (NH_4)_2 + MoO_4 + HNO_3 \longrightarrow (NH_4)_3PO_4 + MoO_3 + NH_4NO_3 + H_2O$$ If there is a better way to go about this (besides inspection; I have been trying that for hours) please let me know.  Any ideas?


Writting a proof for $\lfloor 4x \rfloor = \lfloor x+1/4 \rfloor + \lfloor x+1/2 \rfloor + \lfloor x+3/4 \rfloor + \lfloor x \rfloor$

I am working on an assignment and have to write a proof for the following:  $$\lfloor 4x \rfloor =  \lfloor x \rfloor + \lfloor x+\frac{1}4 \rfloor + \lfloor x+\frac{1}2 \rfloor + \lfloor x+\frac{3}4 \rfloor$$  I have to do by proof by case I know the cases to be as follows  $$0 \le x-\lfloor x \rfloor \lt \frac 1 4$$ $$\frac 1 4 \le x-\lfloor x \rfloor \lt \frac 1 2$$ $$\frac 1 2 \le x-\lfloor x \rfloor \lt \frac 3 4$$ $$\frac 3 4 \le x-\lfloor x \rfloor \lt 1$$  The problem is I don't understand how I can express this.  Case 0 In this case I know that it would be $4n$ here  Case 1 In this case I know that it would be $4n+1$  Case 2 Here it would be $4n+2$  Case 3 Now the last case would end up being  $4n+3$  Can someone help me express this?


Staying in the Schengen Area after the permitted days of entry but before the visa expiry

I was given a Schengen Visa (from Greece) valid from July 17 to August 8, but only 8 days permitted to stay.  My flight is originally July 17-24, but something came up and need to extend the stay until July 28 (additional 4 days).  What do I need to do? Help please!


When pluralizing family (last) names that also happen to be common English words, does the pluralization follow the same rules as the common word?  For example, "the Smith family" can be pluralized as "the Smiths", but what if the family name is "Wolf" or "Fish"?  Would the correct pluralization be "the Wolfs" or "the Wolves"?


A part of my blender render is invisible?

If you render, the roof of the car becomes invisible.  How do I fix this?


I have created 3d model of a little boy but when I render it there are small points on the model what can cause it? There is a plane with material of emission.


Conversion between pressure in PSI and velocity

My question is about whether you can convert the pressure something has to the velocity it will have. For example, if I had water shooting out of a hose at 100PSI, could I calculate the speed that the water would have after it leaves the hose? Is that possible to calculate with just pressure, or would you need more information?


Is it possible to find the host name (Computer name) in my LAN network if I know its IP address?

I want to know whether this can be achieved using terminal. I have tried nmap, nslookup and netstat, and failed.


Finding WiFi Password that is stored in Laptop

I have a laptop with Windows 7. My home has a few WiFi networks, and, for some reason, no one knows the passwords. The laptop can connect to those networks, however.  So, I thought that the laptop must have the passwords stored somewhere in its registry.  Is this true? Can I obtain those passwords?


Why use both fontenc and inputenc in the same document?

What's the point of using both fontenc and inputenc in the same preamble? Why would anyone want to specify an input encoding (with inputenc) and an output encoding (with fontenc) that don't coincide? And if they do coincide, why use both? This question is not a duplicate of . In  two scenarios are described: Scenario 1   When you type ä in an editor set up for Latin-1, the machine stores character number 228.  When TeX reads the file it finds the character number 228 and the macros of inputenc transform this into \"a.  Now fontenc comes into action; the command \" has an associated table of the known accented characters the font has available, and ä is among these, so the sequence \"a is transformed into the command "print character 228" in the current (T1-encoded) font.   In this case the two coincide.  Scenario 2  for instance, of ß:  The machine stores character number 223  The macros of inputenc change this into \ss  fontenc transforms this into "print character 255" (where T1 encoded fonts have a ß character).    In the first scenario what's the point in specifying both inputenc and fontenc if they coincide (e.g. they both associate the character number 228 with the string \"a. In the second scenario, why would you want to convert the character number 223 to the character number 225? Why can't you stick to 223?


How can the output of ldd be checked to see of they exist on a different system or not?

Running ldd on an executable gives the output displayed below.  How can the output be parsed for the library names in the first column and their existence tested on another computer, giving output similar to ldd's output shown below, eg via a remote SSH command, or with the output copied to the target computer and tested there?       linux-gate.so.1 =>  (0xb7728000)     libpthread.so.0 => /lib/i386-linux-gnu/libpthread.so.0 (0xb76f9000)     libdl.so.2 => /lib/i386-linux-gnu/libdl.so.2 (0xb76f4000)     libX11.so.6 => /usr/lib/i386-linux-gnu/libX11.so.6 (0xb75bf000)     libgdk_pixbuf-2.0.so.0 => /usr/lib/i386-linux-gnu/libgdk_pixbuf-2.0.so.0 (0xb759e000)     libgtk-x11-2.0.so.0 => /usr/lib/i386-linux-gnu/libgtk-x11-2.0.so.0 (0xb7136000)     libgdk-x11-2.0.so.0 => /usr/lib/i386-linux-gnu/libgdk-x11-2.0.so.0 (0xb7087000)     libgobject-2.0.so.0 => /usr/lib/i386-linux-gnu/libgobject-2.0.so.0 (0xb7038000)    In a more general manner given a list with some filenames which are in a given column or can be extracted via a regular expression how can their existence be checked for and the output formatted as list with their paths if they exist or some other text stating if they don't exist?


Macbook Air - how to install a dual bootable Ubuntu 14.04 LTS

On my Macbook Air 10.9.2 without crashing the current setup, how can i install as dual boot: Ubuntu 14.04 LTS ? (can anyone please advise some step by step please)


simple way to play sounds every x second in java

I have about 20 different sound, and i want it to be played for example every 1 second. every sound just have a duration about 0.7 second. I don't even know how to import mp3 to java either. How can i do this in java?  UPDATE   try  {       in = new FileInputStream(new File("C:\\Users\\Toshiba\\Downloads\\Music\\adios.wav"));        AudioStream as = new AudioStream(in);       AudioPlayer.player.start(as);        Thread.sleep(1*1000);    } catch (Exception e)   {       JOptionPane.showMessageDialog(null, e);   }   i got new problem. i can't stop it once it start


How do I specify a font for labelfont in caption?

I would like to set the font for the caption label, not just its series, shape or size, I would like to set the font itself. For example, my document's font is set to be Times New Roman, but I would like the caption label to be in a font that exists in another font family or even under a different font encoding. However, the labelfont option of package caption seem to only allow attributes like normalfont, up, it, sl, sc, md, bf, rm, sf, tt and so on, it would not let me specify a literal font, like Georgia, Helvetica or others.  \usepackage[labelfont = bf]{caption}   I am not sure if I have made it clear, please let me know if it is not and I will try to make it clear as possible.  Also, the reason why I am asking this question is, I am typesetting a Chinese document in which the caption label is in Chinese, but in a font I do not like. I am trying to change the font for the caption label to another font for Chinese character.  Thanks in advance!


Caption and label on xltabular environment

I have been trying to add caption and label to a long table (not entirely written below) inside the xltabular environment. After checking ,  and some other posts, I did this:  \usepackage{xltabular} \usepackage{caption} \captionsetup[table]{skip=-10pt}  \captionof{table}{My Table} \begin{xltabular}{\textwidth}{@{}Y|Y|Y@{}}     0.0  & 0    & 0      \\     1.0  & 1000 & 0      \\     2.0  & 2000 & 0  \end{xltabular}   which kinda works. However, I keep getting yellow warning messages:  Package caption Warning: \captionsetup{type*=...} or \captionof outside box or environment on input line 161.  Package caption Warning: The option 'hypcap=true' will be ignored for this particular \caption on input line 161.   Also, \captionsetup[table]{skip=-10pt} stops working if I use \captionof{table}{My Table} and I need it because the space between the table and the caption is too large.  How can I solve these problems without using table environment (it makes my table start in a new page)?


Looking to draw this block diagram in Tikz

I'm looking to create something like this in Tikz environment. Any tips? help?


blender shape face angle inside outside measurement

Background: I'm working on an blender exporter python script add-on. I'm processing shapes based on angles between vertices. I'm accessing this angle using:  class bmesh.types.BMLoop.calc_angle() In blender edit mode I turned on "Face Angle" viewport overlay to show angle on selected edges for debugging.  Notice all angles displayed are INSIDE angles (measured on inside of shape)... EXCEPT: The 73.74 degree angle on right side of picture is OUTSIDE angle? For consistency shouldn't all angles be measured INSIDE? The expected angle on right side should measure the reciprocal - 360−73.74=286.26 Why it it measuring the outside for only this angle but inside for all other angles?


How do I get in the third person character view?

So, I can't get into third person character view. I am playing the Elder Scrolls V Skyrim on Xbox360, but when I'm in an open area (just to make sure there was enough room for the camera to move around) and press the right joystick down it doesn't work.   Any helpful ideas??


Does sum of the reciprocals of all the composite numbers converge?

Surprised that nowhere in web or in MSE is asked it and  is the not considering all of the composite numbers.   Does $$\frac{1}{4}+\frac{1}{6}+\frac{1}{8}+\frac{1}{9}+\frac{1}{10}+\frac{1}{12}+\frac{1}{14}+ \frac{1}{15} + \frac{1}{16} + \frac{1}{18} + \dots$$ converge? If so, how?  Both the Harmonic series and the sum of the reciprocals of all the prime numbers do not converge which doesn't help to answer the question.


Computer can not play sounds when bluetooth speaker connected

This is not a case of me not being able to hear the sounds, but rather my computer seems incapable of playing them in the first place. For example, Youtube videos cannot play, and the Videos app will not even start an MP3. If I turn off the bluetooth speaker, everything works fine.  This is a Photive speaker and I have configured it via Ubuntu "Sounds" app as well as "Pulse Audio Control" to use the High Fidelity Playback (A2DP Sink) option. I've also tried using the "Bluetooth Manager" app (blueman) as well as restarting the devices, and some other questions on AskUbuntu / StackExchange. I would gratefully appreciate any help.


If I have a spawner at y level 12 and AFK there will it run my farms at the the same x and z level above ground (will it load the chunks?)


Restore SQL Server 2012 backup to a SQL Server 2008 database?

Is there a way to restore a SQL Server 2012 database backup to a SQL Server 2008?   I tried to attach file, it does not work.


How to motion track films where track points get out of screen?

Situation, a quadcopter drone video, it flies 500m away with a view corners moves  then does 360 turn and flies back. I want to camera track this, but the trackpoints get out of view after a short while. How to camera track longer video files, where trackpoints gets lost (out screen) after a while ?.  This problem was not related to the sugestion not a duplicate i found a different solution meanwhile. I f someone removes the possible duplication mark i might be able to post the solution here.


Does $\lim_{x \to 4} \sqrt{x-4}$ exist?   The domain of the function is $[4,\infty)$ so does the left hand limit exist? And does the general limit exist?


Interaction between Leyline of Anticipation and Teferi, Time Raveler

With the reprint of  in Core Set 2020, the interaction with  came to mind and I couldn't figure out what is right.  If I have the Leyline and my opponent has Teferi, may I cast spells during my opponent's turn?


I have a problem that when I select certain addons that require parameter changes, I'm not able to edit them, they appear greyed out.  I assume this is a system settings problem (since it happens across versions) and experience something similar when, for example, adding a circle.  I resolved this by changing "new objects enter into edit mode" in the "editing" settings.    Unfortunately even though this setting works for objects it doesn't work for things like the "fracture","ANT", "Sapling etc.  Any ideas?


The trigger is not inserting the field and is not being triggered either

I built a trigger to insert a custom object record (NPSResponse__c) when the SurveyInvitation object is updated. The Developer Consloe did not point out any errors, however when I update a SurveyInvitation record the trigger is not fires. Can anybody help me? Here is the code: trigger crianpsresponsetrigger on SurveyInvitation (after insert, after update) {     if(trigger.isUpdate){          List<NPSResponse__c> NPSResponseList = new List<NPSResponse__c>();                   for(SurveyInvitation si : (list<SurveyInvitation>)trigger.new){             If (si.ResponseStatus == 'Completed' && si.Survey.Name == 'Net Promoter Score'){                                  List<SurveySubject> SurveySubjectList = new List<SurveySubject>([SELECT SubjectId, Survey.Name FROM SurveySubject WHERE (SubjectEntityType = 'Case' AND SurveyInvitationId =: si.Id)]);                 List<SurveyQuestionResponse> NPSSurveyQuestionResponse = new List<SurveyQuestionResponse>([SELECT Question.QuestionName,ResponseValue,CreatedDate FROM SurveyQuestionResponse WHERE (Question.QuestionType = 'NPS' AND InvitationId =: si.Id)]);                 List<SurveyQuestionResponse> CommentSurveyQuestionResponse = new List<SurveyQuestionResponse>([SELECT Question.QuestionName,ResponseValue,CreatedDate FROM SurveyQuestionResponse WHERE (Question.QuestionType = 'NPS' AND InvitationId =: si.Id)]);                  for(SurveySubject ss : SurveySubjectList){                     for(SurveyQuestionResponse npssqr : NPSSurveyQuestionResponse){                         for(SurveyQuestionResponse comsqr : CommentSurveyQuestionResponse){                                                     NPSResponseList.add(new NPSResponse__c(Survey_Name__c=ss.Survey.Name, Caso_relacionado__c=ss.SubjectId,NPS_Question__c=npssqr.Question.QuestionName,NPS_Response__c=npssqr.ResponseValue,Comment_Question__c=comsqr.Question.QuestionName,Comment__c=comsqr.ResponseValue));                         }                     }                 }                              }                      }                          insert NPSResponseList;     }         }


Why can't a Meredith Graph be Hamiltonian?

I need to find out why  is not Hamiltonian  Meredith Graph is so complex to analyze in this regard. Can anyone help me wih their expertise?


I'd like to know when a field from a node it's a paragraph, I only get the type, that it's entity_reference_revisions, I use this method to get the information:  \Drupal\field\Entity\FieldStorageConfig::loadByName()   But I'm not able to get this information   [settings:protected] => Array     (         [target_type] => paragraph     )   The only way I get it's to check directly to the database to see it the name of the field it's in the table paragraphs_item_field_data.  Thanks  Oskar


Why is Cat 5 cable only specified up to 100Mhz, if it's to be used for 100BASE-TX, which surely contains frequencies much higher than 100Mhz?  Likewise, why is Cat 6A only specified to 500Mhz, but is suitable for 10GBASE-T?


Show $\sin x = bx$ has at least 3 real solutions.

Show $\sin x=bx$ has at least 3 real solutions for every $b$, where $-\dfrac{2}{3 \pi} < b < \dfrac{2}{\pi}$.   Some useful facts I am trying to use:  Intermediate value theorem: If $f$ is a continuous real-valued function on $[a,b]$ and $d \in \mathbb{R}$ satisfies $f(a)< d< f(b)$, then there exists a point $c$ in $(a,b)$ such that $f(c) = d$.   Corollary: If $f$ is a continuous real-valued function on $[a,b]$, then $f([a,b])$ is a closed interval.


\url{...} produces a rather wide monospace font. It often does not fit into text width.  If I wish to make \url{...} another font (such as maybe the same font as the text font), how to do it?


How to include multiple spf domains with different mechanisms in a single spf TXT Record

EDIT : How to Mix the different mechanisms (a , mx , ip4 ,  ptr and include) to create single SPF file from 4   I know that 2 simple SPF records like  v=spf1 include:_spf.google.com ~all v=spf1 include:otherdomain.com ~all   can be merged to one as  v=spf1 include:_spf.google.com include:otherdomain.com ~all   I have bit more complex SPF records with mechanisms  like a mx ip4  ptr and include  as shown below  v=spf1 a mx ptr include:icpbounce.com include:spf.mandrillapp.com ~all     v=spf1 mx ip4:x.x.x.x include:mktomail.com ~all      v=spf1 mx ip4:y.y.y.y include:mktomail.com ~all     v=spf1 include:spf.mandrillapp.com ?all   How can merge all this to one TXT record, as mandrilapp is giving me an error      has more than one TXT record that looks like an SPF record   I cant try a trial and error as its in production and i am very new to this SPF domain


What happens in the case of a tie in Clan Wars?

When there is a clan war, what happens in the case of a tie? Does it default to some of the stats used to describe the clan war? or does it have like a deathmatch?


Cannot use code block directly below list

When writing a post with a code, it is not possible to use block code directly after a list.   This is a list It contains some items It's goal is to show that I can't use code below  This is a code sample that is not being parsed.   If I write anything  I can use code now.    The only place I can't use code is right after a list.  Like here, for instance  This is also code that is not being parse  This is code too.   This is normal text.  This is code.


QGIS world map projection with solid Russia (10 degrees over)

I'm fairly new to QGIS. I have a world map, standard WGS84 with 10 degree graticules (see map).   How do I "shift" the whole map over just 10 degrees to give me a complete world map with a solid (unbroken area) Russia?   See red line on map.     I don't need the size or anything else to change, I just want it to be centered 10 degrees over.  [World][1\


Change name of Virtual Desktop in Windows 10

When adding  on Windows 10 they are just named sequentially: Desktop 1, Desktop 2, ... etc  Is there a way to modify these names to provide something more meaningful? i.e. Home, School, Work, Project?    Note: This has been a  for


Wheel user with sudo permissions can't write to file with tee, but can create it. How to fix?

This is my output on CentOS.   [test@test]$ sudo fallocate -l 2M text [test@test]$ sudo echo “This is for test” | tee text tee: text: Permission denied “This is for test” [test@test]$ ls text [test@test]$ cat text [test@test]$ [test@test]$ sudo yes 'This is test' | dd of=text bs=2M count=1 dd: failed to open ‘text’: Permission denied   I keep getting the 'Permission denied' error. But I have sudo permissions.


Why are "quite few" and "quite a few" opposites?

Consider these two sentences:   How many people came?  Quite few. How many people came?  Quite a few.   The first means few people came (less than expected), the second means many (more than expected).  Why the difference, and what exactly is the "a" referring to?


What is the remainder when ${13}^7$ is divided by 9

As the question stated, what is the remainder when ${13}^7$ is divided by 9? There are quite a few online questions similar to this. However, I do not really understand the concept of it.  I have attempted this question by looking for a pattern (as suggested in some online search):  ${13}^1 / 9$ = 4 remainder  ${13}^2 / 9$ = 7 remainder  ${13}^3 / 9$ = 1 remainder  ${13}^4 / 9$ = 4 remainder  ...  There is clearly a pattern of 4, 7, 1 before it repeats itself in the power 4. For power 7, the remainder is therefore 4. I believe the answer to this question is 4 remainder.  My question is how will I approach if the power is much larger than power 7? Say, if we have ${13}^{100}$ divide by 9, is it right to find the remainder using this method:  $100 / 3 = 33.33333 $  Since $33 * 3 = 99$, for the remainder at the 100th power, it will be 4.  Is there a more elegant way of doing this?   Edit:  Actually, this method does not seem to work if the divisible value is larger than 13. Any idea?


How to redirect from FR to COM when using HTTPS

I have two domains : my-domain.com and my-domain.fr  I want to redirect traffic as followed :   my-domain.com:80 -> my-domain.com:443 my-domain.fr:80 -> my-domain.com:443 my-domain.fr:443 -> my-domain.com:443   I've chosen to only use .com, am I right ? I guess yes. Because I only have to manage one certificate : the .COM one.  My /etc/apache2/sites-available/default :  NameVirtualHost *:80  <VirtualHost *:80>    ServerName www.my-domain.com    ServerAlias my-domain.com    Redirect permanent / https://www.my-domain.com </VirtualHost>  <VirtualHost *:80>    ServerName www.my-domain.fr    ServerAlias my-domain.fr    Redirect permanent / https://www.my-domain.com </VirtualHost>   My /etc/apache2/sites-available/default-ssl :  NameVirtualHost *:443  <VirtualHost *:443>    ServerName www.my-domain.com    ServerAlias my-domain.com    DocumentRoot /var/www/my-domain/    ErrorLog /var/log/my-domain/my-domain.com.error.log    CustomLog /var/log/my-domain/my-domain.com.access.log combined     GnuTLSEnable on    GnuTLSPriorities NORMAL    GnuTLSExportCertificates on    GnuTLSCertificateFile /etc/apache2/ssl/certs/my-domain.com.crt    GnuTLSKeyFile /etc/apache2/ssl/private/my-domain.com.key </VirtualHost>  <VirtualHost *:443>    ServerName www.my-domain.fr    ServerAlias my-domain.fr    DocumentRoot /var/www/my-domain/    ErrorLog /var/log/my-domain/my-domain.fr.error.log    CustomLog /var/log/my-domain/my-domain.fr.access.log combined     GnuTLSEnable on    GnuTLSPriorities NORMAL    GnuTLSExportCertificates on    GnuTLSCertificateFile /etc/apache2/ssl/certs/my-domain.fr.crt    GnuTLSKeyFile /etc/apache2/ssl/private/my-domain.fr.key </VirtualHost>   But I'm getting a SSL certificate error when I'm going to my-domain.fr because it tells me that I wanted to go on my-domain.fr and I'm not.


In The End of Time, we see that The Doctor looks at one lady who was alongside Rassilon very peculiarly. Why? Who was she? What was her role? Did the Doctor know her? If yes, how?


Tweaking close requirements to manage the close queue

There have been no shortage of ideas to get the close queue manageable.  Here's one more: let's fundamentally re-think how many votes it takes to close a question.  Currently, diamond mods can close anything unilaterally, while all other users must always cast a total of 5 votes, without exception.  Can we leverage the reputation system—which is, after all, meant to represent how much the community trusts a user—to do better?  20K users are described as "Trusted Users."  Can we trust them to, say, unilaterally close questions from the close queue that have negative scores with no answers?  Or even negative scores with no upvoted answers? What if we let them, say, cast two close votes for questions (from the queue) that have a score of zero or less?  I don't think I'm alone when I say that I'd be more motivated to tackle that queue if I didn't feel like Sisyphus, more so now that there are over 100K questions in there.  It's incredibly de-motivating thinking about how little your daily allotment of 40 votes is doing against this avalanche.


How do I disable auto-maximizing of newly launched windows in GNOME?

Each time I open any application, it zooms to fill-up the entire desktop and so I am always forced to use "Unmaximize" using Alt+Space menu.


Bibliography references by order of appearance

I am putting together a big document based in many other small ones, and, as it is, I have a lot of references, much more than I wish to order by hand.   Is there a way to number these references by order of their appearance and not in the order I wrote them in the bibliography?  Let's say something like this:  ...  The code is amazing (\cite{FirstGuy}) because it rules (\cite{SecondGuy}) and this is proven in \cite{ThirdGuy}  ...  \begin{thebibliography}{99}   \bibitem{ThirdGuy} \textbf{G. Third}. \emph{Consistent proves of amazing code} \bibitem{FirstGuy} \textbf{G. First}. \emph{Comments on amazing code} \bibitem{SecondGuy} \textbf{G. Second}. \emph{Code that rules}   should produce something like this:  ...  The code is amazing ([1]) because it rules ([2]) and this is proven in [3]} ...  [1] G.First. Comments on amazing code. [2] G.Second. Code that rules. [3] G.Third. Consistent proves of amazing code.   Is there a way to achieve this without using BibTex or similar tools? (because the effort required to import them is similar to sorting them by hand).  Thanks!


Why does the accepted answer not come first?

On the question , if you sort by "votes" or "active", the accepted answer (with the green checkmark) is not the top answer. (At least, this is what I am seeing in my browser.)  This is the only place I've seen this happen, and it seems to go against the standard for Stack Overflow.  Is this a bug?  If not, what is going on?


Compute the integral $\int_{A} x^m y^n z^p (1-x-y-z)^q dx dy dz$

Let $A =$ {$(x,y,z) \in \mathbb{R}^3 |$  $x,y,z \geq 0$ and $x+y+z \leq 1$}.   Compute the integral $$\int_{A} x^m y^n z^p (1-x-y-z)^q dx dy dz$$  using new variables $u = x+y+z$, $v=\frac{y+z}{x+y+z}$, $w=\frac{z}{y+z}$.  Also, although it was not stated in the problem, I'm assuming that $m,n,p,q \in \mathbb{Z}$.   Since $f(x,y,z)=(x+y+z, \frac{y+z}{x+y+z}, \frac{z}{y+z}) = (u,v,w)$, $f^{-1}(u,v,w) = (u(1-v), uv(1-w), uvw)$  Thus J $= \begin{vmatrix} 1-v & -u & 0\\  v(1-w) & u(1-w) & -uv\\  vw & uw & uv\\ \end{vmatrix} = u^2v$  Skipping the part where I find the new limits of integration, and skipping some algebraic simplification we have:  $$\int_{A} x^m y^n z^p (1-x-y-z)^q dx dy dz$$   $$= \int_{0}^1 \int_{0}^1 \int_{0}^1 u^{m+n+p+2}(1-u)^q v^{n+p+1}(1-v)^mw^p(1-w)^n du dv dw$$  However, I have no  idea where to go from here. Any help would be much appreciated.


I have this function for a 4x4 keypad:   uint8_t GetKeyPressed()  {   uint8_t r,c;    KEYPAD_PORT|= 0X0F;    for(c=0;c<4;c++)   {      KEYPAD_DDR&=~(0X7F);       KEYPAD_DDR|=(0X40>>c);      for(r=0;r<4;r++)      {         if(!(KEYPAD_PIN & (0X08>>r)))         {            return (r*4+c);         }      }   }  return 0XFF;//Indicate No key pressed }   Is it ok, or it has some bugs in it ?


Where to ask technical problems/bugs about video games

As the title says, is there a SE site which lets people ask about technical bugs / problems about video games? Made-up example, I found a bug where you can die randomly while flying in Minecraft.


Label Text thows InvalidOperationException on update c# winforms

I am trying to display a basic clock from system time. I don't understand why this is crashing. I am hoping someone can help me to understand my error here.   At this point the form is just a label with short time displayed. I am trying to just make it update the label text on its own.   The label shows the time just fine on load. But when the timer_elapsed occurs the error is thrown  private void Form1_Load(object sender, EventArgs e) {     lblClock.Text = DateTime.Now.ToShortTimeString();     timer = new System.Timers.Timer();     timer.Interval = 1000;     timer.Elapsed += timer_Elapsed;     timer.Enabled = true;     timer.Start(); }   void timer_Elapsed(object sender, System.Timers.ElapsedEventArgs e) {     lblClock.Text = DateTime.Now.ToShortTimeString(); }   The error is   InvalidOperationException was unhandled by user code  Why does this work on load but not on update?    This was marked as a duplicate, but I have to disagree. Based on the linked duplicate thread the questions aren't the same. This question refers to why the exact same method works on load but not on call. The other thread is simply asking in general how to update a UI.


Handling unconventional source directory for a web project in maven

I've inherited a web project (Servlets) which is currently build inside eclipse.  I want to add maven around it. But the project's source directory is not following the maven convention. Instead of being inside src/main/java, it's src/package/name/...  I don't want to change anything right now because they are working at full speed towards a milestone. Can I configure maven to accept src/ as the java source directory ? Thanks


How to install OS without deleting the hard disk data?

i had installed Windows 7 in my laptop and tried to install ubuntu recently. This attempt  damaged OS windows 7 and unable to boot up. I have tried to repair with Win7 DVD and failed. Again I have tried to install Windows 7 with DVD, found no separate partition (earlier there were 3 nos of partition) in hard disk. Expecting all data remains in HDD. I would like to install Win 7 without deleting existing data. Kindly help me to install OS without formatting / loosing the data.


So, I main playing the bot lane, but I like to be capable in all positions. So what DOES make a jungle champion, a jungle champion? I know one key element is self-sustain, but at the same time, I know of several champions that are viable in the jungle, that have no real source of self-sustain. This includes a lot of the champions that are only "Glass Cannon" style junglers, such as Shaco, and a couple others, like Volibear. I know Volibear's passive restores his health, but as it has 2 minute cool down, I don't consider it to be a sustain tool. After looking at Shaco and some other glass cannons, I tried Talon in the jungle, and while it got the job done, it didn't feel like it was as strong as a jungler like Shaco, Kha'Zix or Master Yi. I want to know, is there some sort of common trait I can look for, to see who is the most viable in the jungle. Please keep in mind, that for me Viable doesn't necessarily mean that it works, it means it works well enough to be competitive through all levels of play. Please don't recommend things like jungle Leona or Jungle Sivir.  So in general, I guess I'm looking for how to determine if a champion can jungle well. How big a factor is sustain (Lifesteal/Spell Vamp/Mana Restore)? What kinds of damage output are needed? What about defenses? I'm looking for stats, not just general features.


View site with a specific reputation value (lower than your own of course) or as a specific user (for mods)

To be honest I find it hard to keep up with all the changes, and very frequently I have to go look at the privileges list to see whether a user (that I'm looking at, so I have his reputation value) has a certain privilege or not.  However, I still don't know what that user will actually see or how the site actually behaves for that user.  There's quite a number of posts here on meta about "where did this go" and "why can't I" and I can't really tell either way how a site behaves for a user with a reputation level of 2500.  So, I propose the following functionality:   For all users, be able to view the site as though you had less reputation than you actually have Bonus-feature: For all users, be able to use the site at that reputation level, unless some features of low-level users conflict with your actual functionality For mods, be able to view the site as a specific users (be able to see all he sees, exactly the way he sees it), but of course not pose as that user (ie. things I do would still be me)   The UI could be merged into the mod menu and the privileges menu:    (Note, I chose a user randomly, Olivier Pons is in no way related to this question or flags, or whatever that I know of.)


When people say that every moving particle has an associated wave, do they mean that the particles will move up and down physically, for example when we say that a moving electron has a wave associated with it, does the electron physically oscillate?  Or is it some other wave, like a probability wave? I really don't understand the latter.


I am trying to turn a fresh install of Ubuntu 14.04 into an X2go server. I have followed the instructions here:   I have taken these steps:   su Add the line below to /etc/apt/sources.list  deb http://us.archive.ubuntu.com/ubuntu trusty main universe  add-apt-repository ppa:x2go/stable   I get this message:  cannot add ppa: ppa:x2go/stable please check that the ppa name or format is correct


I was searching for more answers on the internet. I kept searching, and I found one thing that help me a little. I went back to Terraria and tried it out, but the Lunatic Cultist didn’t spawn.  Does the Lunatic Cultist spawn on an iPad?


Do North Americans pronounce "solder" as "sodder"?

In a recent(-ish) episode of the Big Bang Theory, the men recruit the women to help out in the lab, and they had to do a lot of soldering.  Throughout the episode the cast pronounced "solder" as "sodder" which I thought was interesting. Is this the pronunciation used in the whole of the US (and Canada)? What happened to the "l"?


Mahalanobis distance between 2 points doesn't work when covariance matrix has values close to 0

I am working on a project where I am trying to replicate a randomized experiment from an observational study data, using Mahalanobis distance matching to ensure that the control and treated groups are similar. I have seen several websites talking about Mahalanobis distance as the distance between a point and a distribution. However, from what I understand from this academic paper (), and this website (), the Mahalanobis distance can also be calculated between two points (each point representing a vector of features).   So that is what I am trying to do as some sources say Mahalanobis distance is a better measure than the Euclidean distance. However the Mahalanobis distance involves using the inverse of the covariance matrix of the data-set used. Some of the values in my covariance matrix turn out to be very small (close to 0), and when I try to calculate the inverse of this covariance matrix on Matlab, I seem to get a matrix of inifinity values.  Does anyone know how to tackle this problem? Am I understanding something wrong?


Converting point XY to page units XY using ArcPy

I am using ArcPy to export PDFs from my ArcGIS Server application. I want to move a TextElement in my layout view to the centroid of a selected feature. I can get the centroid of the feature, but that's in my projected coordinate system (PCS). I need to convert that point into inches in my layout view. elements = arcpy.mapping.ListLayoutElements(mapDoc, "TEXT_ELEMENT")     for elem in elements:         if elem.name == "SiteText":             elem.elementPositionX = center.X             elem.elementPositionY = center.Y  center.X and center.Y are in a projected coordinate system (PCS), not inches. I know it can be done with ArcObjects, as I've done it in desktop addins using C#. I need to do it from ArcPy and I don't see how. Any ideas?


How do I make my screenshot ask me what to do next every time?

I take screenshots a lot. I usually take screenshot of an area, I then recheck if I have the desired area and then copy it to clipboard.  I want to change this behaviour so that immediately upon  pressing Shift+PrntScr the screen capture application allows me to select an area, and immediately afterwards it provides me with the option to save to a particular location or clipboard.  I want Shift+PrntScr to bring up a pop-up screen like this:


Why the Sets defined in the Cumulative Hierarchy transitive?

On Page 64, Set Theory, Jech(2006), define the following, by transfinite induction:        $V_0=\emptyset$,      $V_{\alpha+1}=P(V_{\alpha})$,    $V_{\alpha}=\bigcup_{\beta<\alpha}V_\beta$, if $\alpha$ is a limit ordinal.      How can we prove $V_{\alpha}$ is transitive by induction.  I tried what if other set, say $\{\{\emptyset\}\}$, is disignated as $V_0$. It turns out the transitive property fails. So somehow I should incoorperate $V_0=\emptyset$ into the induction. But then I stared at it, I stared at it, I just don't know what should I do.


Is there a term denoting the writing of words using numbers instead of letters?

Sometimes, more in some languages than in others, a word is spelled using one or more numbers instead of letters. Is there a term for this?  The only example I can think of in English is se7en (seven).   Therefore,     The number se7en was not spelled entirely with letters; it was written in   ______.


Need a proof to show all the units are satisfied $\mathbf{Z}\sqrt{2}$ is the all the integer solution in Pell equation

We know the integer solutions of Pell's equation $$a^2-2b^2=\pm1$$ correspond to the units of $\textbf{Z}[\sqrt{2}]$. How can we prove this?


Sequence of random variables $X_n$ converging in probability to $X$ and $X_n$ converging in distribution to $Z$, then $X$ has same distribution as Z?

Suppose $\left\{X_n\right\}_{n\in\mathbb{N}}$ is a sequence of random variables on $(\Omega,\mathscr{F},\mathbb{P})$ such that $X_n$ converges in probability to $X$. Moreover suppose that $X_n$ converges in distribution to a random variable $Z$. My question is does $X$ have the same distribution as $Z$?  And could you please provide an proof for it?  Thanks =)


Vector space of real vectors over field complex scalars.

Let $V = \{(a_1,a_2,\ldots,a_n): a_i \in \mathbb{R}\ \text{ for } i = 1,2,\ldots,n\};$ So $V$ is a vector space over $\mathbb{R}$. Is $V$ a vector space over the field of complex numbers with the operations of coordinatewise addition and multiplication?  I don't need an actual answer for this, as I just want to confirm that I understand what the question is asking. Paraphrasing: If $V = \mathbb{R}^n$ and $\mathbb{F} = \mathbb{R}$, then we know that $V$ is a vector space. If $\mathbb{F} = \mathbb{C}$, then is $V$ still a vector space (Is the set of real vectors $v \in \mathbb{R}^n$ over the field of complex scalars a vector space)?


Sum of multiple probability distributions

Background:  I try to estimate the potential energy supply within a geographical area using spatially explicit data.   For this purpose I use a Bayesian network and several spatial data layers as input data (e.g resource supply, conversion efficiency). The study area is devided into smaller area entities. For each entity my Bayesian network model reads the input data and computes the corresponding energy supply (MCMC simulations). As a result I obtain for each entity a probability distribution of the expected energy supply (e.g Distr or Distr 2).  However, I am equally interested in the total supply within the study area. That means I need to aggregate (sum) the potential energy supply of all the individual entities in order to get the overall supply potential within the area (e.g. Distr 3).   Question:    I would like to combine several probability distributions by adding their values into one single probability distribution (see above).   What is the correct mathematical/statistical term of the operation I want to do?   Below I provide a graphical explanation of what I would like to do.


My site works fine in local system, Upload code and database in server show Error.  Fatal error: Class 'SelectQuery' not found in /*/includes/database/database.inc on line 813


Where to ask questions regarding paranormal activities?

Just now me and some of my friends are having a conversation about the paranormal world, activities, ghosts, spirits and all. So I came home and searched on the Internet.  Then stackexchange.com came into my mind. I'm a big fan of  the Stack Exchange sites and want to know: is there any site where one can ask questions regarding paranormal activities and other related things?


Will "Ubuntu for Android" (12.04) work with the Samsung Galaxy S2?

I'm trying to buy a new Android phone and I own an Ubuntu 12.04 computer...  I have the choice of a Google Galaxy Nexus, Samsung Galaxy S2 and an HTC Sensation XL.  I am aware that the HTC already works with it, but I would prefer to buy the Samsung. I already have the phone hardware specifications and have checked, but I am not sure about the Samsung or the Nexus.  So which of these phones work with Ubuntu 12.04's 'Ubuntu for Android' feature?


This is probably a very basic question in complex numbers.  First define $\sqrt{w} := \sqrt{|w|}e^{i(Arg(w)/2)}$ where Arg is the principal argument function.  Prove that if $Re(z)>0$ then $|z+\sqrt{z^2-1}| \ge 1$ with equality holds only when $z \in (0,1] \subset \mathbb{R}$.  There is also a hint given that I haven't managed to prove:  Hint: first check that $Re(\bar{z} \sqrt{z^2-1}) \ge 0$ for every z under consideration.


How to extend the heading to the full text width?

How can I make the headings (with fancyhdr) extend to the full width of the text column?  The width of the text is larger than normal because it has been expanded using the geometry package. For this reason the right-aligned headings do not touch the right margin.  Here is a MWE:  \documentclass{article} \usepackage{lipsum} \usepackage{fancyhdr} \pagestyle{fancy}  \usepackage[margin=1in]{geometry}  \begin{document}  \lhead{Left} \chead{Center} \rhead{Right}  \lipsum \lipsum \end{document}


Trying to do an Ubuntu/Windows dual install but only Windows 7 pops up

So I've been running Ubuntu without Windows. I got a Windows 7 live CD and tried to do a Windows 7/Ubuntu dual boot but I couldn't get the boot to load correctly so I decided to go back to just Ubuntu. However now I just have a Ubuntu install and it won't boot. I've tried boot-repair and it still won't boot.    What should I try next?


Space of homeomorphisms Homeo$(S^1)$ of $S^1$ deformation retracts onto $O(2)$

How can we prove that the space of homeomorphisms Homeo$(S^1)$ of $S^1$ (strong) deformation retracts onto the orthogonal group $O(2)$?  I know that this result is proved by  in his paper   I want to learn somewhat more elementary proof if possible, or at least the idea of the proof.  Added Later (The topology on the space of homeomorphisms Homeo$(S^1)$ of $S^1$). This is footnote 7 from Hutchings' lecture notes, :      We topologize the space Maps$(X, Y)$ of continuous maps from $X$ to   $Y$ using the compact-open topology. For details on this see e.g.   Hatcher. A key property of this topology is that if $Y$ is locally   compact, then a map $X \rightarrow$ Maps$(Y,Z)$ is continuous iff the   corresponding map $X \times Y \rightarrow Z$ is continuous.


Probability of "clock patience" going out

Here is a question I've often wondered about, but have never figured out a satisfactory answer for. Here are the rules for the solitaire game "clock patience." Deal out 12 piles of 4 cards each with an extra 4 card draw pile. (From a standard 52 card deck.) Turn over the first card in the draw pile, and place it under the pile corresponding to that card's number 1-12 interpreted as Ace through Queen. Whenever you get a king you place that on the side and draw another card from the pile. The game goes out if you turn over every card in the 12 piles, and the game ends if you get four kings before this happens. My question is what is the probability that this game goes out?  One thought I had is that the answer could be one in thirteen, the chances that the last card of a 52 card sequence is a king. Although this seems plausible, I doubt it's correct, mainly because I've played the game probably dozens of times since I was a kid, and have never gone out!  Any light that people could shed on this problem would be appreciated!


What are the options for a non-EU national who wants to extend his stay in Switzerland (totaling less than 90 days)?

I am currently working in Switzerland on work permit and my parents obtained a Schengen Visa for travel which has a validity of 90 days. In the visa, the duration of stay is mentioned to be 55 days  - this is same as the original itinerary of the travel.    Now that they are in Switzerland for last 40 days - I wish to extend their stay for couple of more weeks which would result in their duration of day as 75 days (which is more than 55 days but well within 90 days of validity).  Could anyone please suggest if I would need a formal approval process from local canton or national immigration office?


How to create iso from installed Ubuntu 14.04 on Vmware?

I want to create an Ubuntu 14.04 iso with is all installed packages and software. Ubuntu is installed on Vmware workstation.  I want to be able to install this iso on new systems.


Getting "ensure" / "finally" functionality in a shell command (not script)?

I need to know whether a command has succeeded or failed, and unconditionally run some cleanup afterward.    Neither of the normal options for executing sequential commands seem to be applicable here:  $ mycmd.sh && rm -rf temp_files/    # correct exit status, cleanup fails if mycmd fails $ mycmd.sh ;  rm -rf temp_files/  # incorrect exit status, always cleans up $ mycmd.sh || rm -rf temp_files/    # correct exit status, cleanup fails if mycmd succeeds   If I was going to do it in a shell script, I'd do something like this:  #!/usr/bin/env bash mycmd.sh RET=$? rm -rf temp_files exit $RET   Is there a more idiomatic way to accomplish that on the command line than semicolon-chaining all those commands together?


Dedupe SQL Server Table [stored procedure]

I'm looking to dedupe a table using a stored procedure. There is no 1 column that is unique, so I'd have to combine 2 or more columns to get a unique identifier. ID column is identity int, but is generated by sql automatically at the time data is imported. I need to somehow combine 2 or more columns excluding ID column to get a unique identifier so I can strip out anything that's duplicated.   From there I figured it would make the most sense to do the following [correct me if my approach is wrong].    create temp table query table using dedupe logic import query results into new temp table drop original [or delete contents?] recreate original[or repopulate?] import data from temp drop temp table   I have the following columns. I think sessionid+callflow is unique.   sessionid,  legid,  dialednumber,  callerid,  calldatetime,  dayofweek,  hourofday,  end_type,  callduration,  callorder,  callflow,  ID,  [pk] origin


In British English is it acceptable to say "securitization"?

In general I find the financial term "securitization" written with "z", but in some Basel Committee documents I've found "securitisation" with "s".  I think it is more common the term with "z", may I use it if I write in British English?  In particular I'd like to know if it is OK if I use the "z" form for this term while I'm using "s" form for other non-financial terms.


Does casting a spell with a higher level spell slot change the level of the spell?

I know that it’s possible to cast spells with a higher level spell slot than what it’s original spell level requires and several spells even give extra benefits for doing so. What I was wondering is if you cast a spell with a higher level spell slot, does the spell become the same level as the spell slot.  For example is someone casts Scorching Ray (a second level spell) with a seventh level spell slot, would the resulting spell be a seventh level spell or a second level spell? I’m curious about this because I want to know how things like counter spell and dispel magic interact with this mechanic.  Thanks!


Is there a simple way in .NET to quickly get the current protocol, host, and port? For example, if I'm on the following URL:  http://www.mywebsite.com:80/pages/page1.aspx  I need to return:  http://www.mywebsite.com:80  I know I can use Request.Url.AbsoluteUri to get the complete URL, and I know I can use Request.Url.Authority to get the host and port, but I'm not sure of the best way to get the protocol without parsing out the URL string.  Any suggestions?


Mail goes to spam folder ( php mail function )

This code what i am using to send mail but unfortunately mail goes to spam folder. I tried both gmail and hotmail but case is same . php code is:  <?php if($_POST) { //check if its an ajax request, exit if not if(!isset($_SERVER['HTTP_X_REQUESTED_WITH']) AND strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) != 'xmlhttprequest') {     die(); }   $to_Email       = "zinan09@gmail.com"; //Replace with recipient email address $subject        = 'My email from Somebody out there...'; //Subject line for emails  //check $_POST vars are set, exit if any missing if(!isset($_POST["userName"]) || !isset($_POST["userEmail"]) || !isset($_POST["userMessage"])) {     die(); }  //Sanitize input data using PHP filter_var(). $user_Name        = filter_var($_POST["userName"], FILTER_SANITIZE_STRING); $user_Email       = filter_var($_POST["userEmail"], FILTER_SANITIZE_EMAIL); $user_Message     = filter_var($_POST["userMessage"], FILTER_SANITIZE_STRING);  //additional php validation if(strlen($user_Name)<4) // If length is less than 4 it will throw an HTTP error. {     header('HTTP/1.1 500 Name is too short or empty!');     exit(); } if(!filter_var($user_Email, FILTER_VALIDATE_EMAIL)) //email validation {     header('HTTP/1.1 500 Please enter a valid email!');     exit(); } if(strlen($user_Message)<5) //check emtpy message {     header('HTTP/1.1 500 Too short message! Please enter something.');     exit(); }  //proceed with PHP email. $headers = 'From: '.$user_Email.'';  @$sentMail = mail($to_Email, $subject, $user_Message .'  -'.$user_Name, $headers);  if(!$sentMail) {     header('HTTP/1.1 500 Could not send mail! Sorry..');     exit(); }else{     echo 'Hi '.$user_Name .', Thank you for your email! ';     echo 'Your email has already arrived in my Inbox, all I need to do is Check it.'; } } ?>   Is there any missing function which i need to add or modify to solve this problem


"have been requested", "has been" or "had been"

I always have difficulty in sorting out between "have been" and "had been", I face this issue a lot.  As an example, which one is correct?        The items have been requested by your team    The items had been requested by your team


My main language is Dutch and I was wondering if there is a word for being in between 2 opinions.  Let me give you an example:   I am against lowering the drinking age, but at the same time not really as long as its being used responsible.   It's a bit of yes and no.  Hope you guys can help me out and teach me (and hopefully others) something.


I give my git colorful prompt but it never fully works. After so many trails I've pinned point where the problem is (completely stripped git out of the problem). Here it is, manifesting the symptom as simple as possible:  Following up on , I need to close escape sequences with \] in order for 'readline' to correctly calculate the prompt's visible length It works with PS1 setting statically, but not dynamically:       echo -e '\e[33m\]00\e[0m\]' | tee /tmp/p      PS1="\n\w`cat /tmp/p`\\\$ "      PS1='\n\w`cat /tmp/p`\\\$ '      echo -e '\[\e[33m\]00\[\e[0m\]' | tee /tmp/p


Showing that $n$ is pseudoprime to the base $a$

Show that if $n=\frac{a^{2p}-1}{a^2-1},$ where $a$ is an integer, $a>1$, and $p$ is an odd prime not dividing $a(a^2-1)$, then $n$ is pseudoprime to the base $a$.  Let $n=\frac{a^{2p}-1}{a^2-1}=1+a^2+(a^2)^2+(a^2)^3+\cdots$.  Then $n-1=\frac{a^{2p}-1}{a^2-1}-1=\frac{a^{2p}-a^2}{a^2-1}=a^2\frac{(a^2)^{p-1}-1}{a^2-1}.$  I have kind of hit a roadblock with this proof. I'm stuck trying to show that $n-1$ is even and that $p | (a^{2p}-1)\equiv 0 \mod p$.  Is there some obvious steps that I'm missing


Countable noun with irregular plural form

How can I express a countable noun together with its irregular plural form? For example, we may have the following sentence:     Find all critical point(s) of this function.   Since we do not know if the function has one or more critical points, we use the expression "point(s)".  What if the noun has an irregular plural form?  For example, should one say     Find all maximum/maxima of the function.   instead of using the parenthesis as we did in "point(s)"?


tlmgr, changing repository, containerchecksum

I change tlmgr repository  sudo tlmgr option repository http://mirror.switch.ch/ftp/mirror/tex/systems/texlive/tlnet   Then when trying to install a package, e.g.  tlmgr install logreq   I get the following error:  Unknown directive ...containerchecksum c59200574a316416a23695c258edf3a32531fbda43ccdc09360ee105c3f07f9fb77df17c4ba4c2ea4f3a5ea6667e064b51e3d8c2fe6c984ba3e71b4e32716955...  /usr/share/texlive/tlpkg/TeXLive/TLPOBJ.pm line 210, <$retfh> line 5579   How can I make this work?    By installing texlive from scratch as described in tug.org/texlive/quickinstall.html and (IMPORTANT) not forgetting to change the path as described in the mentioned link I access the TexLive 2016 version.   tex --version  TeX 3.14159265 (TeX Live 2016)  However, the checksum problem persists.