Determining if the series $\sum_{n=2}^\infty {1\over {n\ln(n)\ln(\ln(n))}}$ is convergent or divergent and justifying the answer.

By far, these infinite series and sequences have been my biggest problem in calculus 2, and this problem really puts my limited knowledge to the test.  I have found that posting these pictures helps show everyone what I have learned so far, and then I'll try to solve it myself.  Chapter and section names:    Rules that my book gives me to solve these problems. This shows more of what I should and do know:    Looking at those rules, it doesn't really even seem to help me with this problem. The only way I could see this being solved with what I know is with the integral test.  Also, note that it starts at 2 (I almost missed that myself).  If I'm going to try to use the integral test, then here is my book's definition of it:    And here is the question again: Determining if the series $\sum_{n=2}^\infty {1\over {nln(n)ln(ln(n))}}$ is convergent or divergent and justifying the answer. I honestly don't know where to start with this one, I would try but there are a lot of changes from previous questions, and it makes it a lot harder.  Any help is greatly appreciated. Thank you.


How to detect reliably Mac OS X, iOS, Linux, Windows in C preprocessor?

If there's some cross-platform C/C++ code that should be compiled on Mac OS X, iOS, Linux, Windows, how can I detect them reliably during preprocessor process?


Title of short story: God granting immortality to others to find a way to kill himself

I am looking for a short story I read a long time ago.  In it, a man dies and finds himself in a dark and featureless afterlife with a disembodied voice that calls itself god.  That god reveals that there is indeed life after death, but only for a selected few, and it consists of nothing more than this void with no contact to others.   Faced with the prospect of eternity alone in that void, the man states his intent to find a way to end his own existence for good. The god answers that it will do anything in its power to prevent that.   After some more back-and-forth the man resolves to find a way to destroy god. God reveals that this is indeed the only reason for the existence of the universe and that afterlife: Because god wishes to find a way to cease to exist.  The story ends, I believe, with something akin to     "The man started to think about the problem. He knew he would succeed eventually; after all he had infinite time"


refcheck and biber -- warnings on uncited entries

\refcheck does not work with biber apparently, as in the following example. Does anyone have a work-around? What do you guys use instead?  % arara: pdflatex % arara: biber % arara: pdflatex % arara: pdflatex  \begin{filecontents}{\jobname.bib} @BOOK{foo:2012a,   title = {My Title One},   publisher = {My Publisher One},   year = {2012},   editor = {My Editor One},   author = {Author One} }  @BOOK{foo:2012b,   title = {My Title Two},   publisher = {My Publisher Two},   year = {2012},   editor = {My Editor Two},   author = {Author Two} }  @BOOK{foo:2012c,   title = {My Title Three},   publisher = {My Publisher Three},   year = {2012},   editor = {My Editor Three},   author = {Author Three} } \end{filecontents}  \documentclass{article}  \usepackage{refcheck} \usepackage[backend=biber,natbib=true,backref=true,doi=true,url=false,style=alphabetic]{biblatex} \addbibresource{\jobname.bib}   \begin{document}  Hello world \cite{foo:2012a,foo:2012b}.  \nocite{*}  \printbibliography  \end{document}


How to use traditional (national/native) dates and calendars?

How can use non-Gregorian dates and calendars?  I adjust Drupal setting to my native language (fa) and native location (Asia/Theran) but month name and number of years also in Gregorian yet (however there are translated to my native language-persian).  I already use format_date() or date() in theme files, but this function is not locale-aware, which means that it always outputs English language data, such as day and month names and ordinal number suffixes.  I want to show the month names in the native language (e.g. Chinese, Islamic, Hebrew, Farsi/Persian) and use the national calendar (e.g. Irani, Shamsi, Jalali).  I want to understand is there any module or hardcoding solution in Drupal to show dates and calendars in other non-Gregorian calendars.  Any suggestions?


Arithmetic Overflow error converting expression to data type int inserting records

while I inserting records in a table it throws :  Arithmetic overflow error converting expression to data type int.  Code:  create table JEmp ( J_Id int Identity, J_Name varchar(100), J_Contact int, J_City varchar(100), primary key(J_Id) )  insert into JEmp(J_Name, J_Contact, J_City)  values ('David Warner', 9821766418, 'New York')


Why does friction does not depend upon area of contact?

Why does friction does not depend upon area of contact ? Now we know that friction=(coefficient of friction)*Normal.So also is, why does friction arise.Is it because of the irregularities of a surface or because of the electrostatic forces in between the surfaces?


How to hide one Chrome tab, not all, and not pin it of course as it won't hide it ? Or how create chrome addon (in javascript) to hide one tab ?


Deriving the maximum likelihood for the parameters in linear regression

Notation: $\textbf{w}$ is an M-dimensional vector of parameters (including the bias parameter), $\textbf{x}_n$ is an M-dimensional vector of the features of each training example, $\textbf{t}$ is an N-dimensional vector of target values - where $t_n$ is the output of the nth training example and finally, $\Phi$ is an $M \times N$ design matrix.  During studying linear regression, I naturally came across the derivation of the normal equation. In his book, Christopher M. Bishop begins by the log of the likelihood function given by:  $$ \frac{N}{2} \ln \beta - \frac{N}{2} \ln(2\pi) - \frac{\beta}{2}\sum_{n=1}^N\{t_n - \textbf{w}^T \phi(\textbf{x}_n)\}^2 \tag{1} $$  With the goal of calculating the maximum likelihood of the parameters, he then calculates the derivative with respect to $w$:  $$ \bigtriangledown p(\textbf{t}| \textbf{w},\beta) = \beta \sum_{n=1}^N\{t_n - \textbf{w}^T \phi(\textbf{x}_n)\}\phi(\textbf{x}_n)^T \tag 2 $$  After which he sets the derivative to zero, in order to maximise the likelihood function  $$ 0 = \sum_{n=1}^N t_n \phi(\textbf{x}_n)^T - \textbf{w}^T \bigg(\sum_{n=1}^N \phi(\textbf{x}_n)\phi(\textbf{x}_n)^T \bigg) \tag 3 $$  So far so good. But then, the result for the maximum likelihood of the parameters $w$ is written as:  $$ \textbf{w}_{ML} = (\Phi^T\Phi)^{-1} \Phi^T \textbf{t} \tag 4 $$  My own derivation from equation $(3)$ to equation $(4)$ goes along the following lines:  \begin{align*} \Phi^T \Phi \textbf{w} &= \Phi^T \textbf{t} \tag 5 \\  (\Phi^T \Phi)^{-1} \Phi^T \Phi \textbf{w} &= (\Phi^T \Phi)^{-1} \Phi^T \textbf{t} \tag 6 \\ \textbf{w} &= (\Phi^T \Phi)^{-1} \Phi^T \textbf{t} \tag 7 \end{align*}  My question is this: How does one go from equation $(3)$ to equation $(4)$. How does the supposed $ \textbf{w}^T \phi(\textbf{x}_n) \phi(\textbf{x}_n)$ become $\Phi^T \Phi \textbf{w}$ ? I do of course understand that given the dimensions of the matrix $\Phi$ and the vector $\textbf{w}$, that this is the only way to multiply the two entities. But what is the steps that one would follow in a formal derivation in order to reach such a result?


Prove : If $I=(p(x))$ is a prime ideal in $ F[x]$ then $p(x)$ is irreducible.my claim is F need not to be field.

In this problem even if I relax the condition that $F$ is a field,then it still remains true, I guess, because if $p$ is reducible, then $p=fg$ where $f,g$ are both nonunit polynomials. Now $fg$ is in $(p)$ but none of $f$ and $g$ are in $(p)$ which contradicts that $(p)$ is prime.  Here the only requirement is that $F$ be an integral domain so that $f(x)$ and $p(x)$  can be associate.


Let $G$ be a cyclic group of order $n$ generated by $a$. Then $a^{k} = e$ if and only if $n | k$.   Proof:       I have a question about the above proof. Why is it assuming in both sides that $a^{n}=e$?


Will I be demoted to a lower league in Starcraft 2 if I don't play?

I've just been promoted from platinum league to diamond and master pretty fast (in 4 vs 4). This was totally amazing for me but I'm afraid I will be demoted again to a lower league as fast as I came higher.   If I don't play any 4 vs 4 anymore, will they demote me to a lower league automatically or do they only do so, if I play?


My pc was unused for several months(its a 5 year old acer desktop) and on boot up a screen came up indicating that the CMOS battery was low. Any time I restarted, as expected, the same screen came up and the time and date reset. However, I left the PC on overnight and the battery seems to have magically fixed itself. I know people are saying that the CMOS battery is not rechargeable but it seems that, in this case, that is exactly what has happened. Anyone have any insight to this phenomena? Just curious now.


Expectation of nonnegative Random Variable

Can someone help me give me some pointers as to how to prove this relation?


Do I need a passport to travel from Scotland to London? Is there any border patrol or immigration office that requires documents to re-enter the UK by train?


Following some suggestions I used:  \DeclareFieldFormat{titlecase}{\MakeSentenceCase{#1}}   to SentenceCase the title.  However, only the name of the conference and not the actual title seems to be affected   A. C. Bahnsen, A. Stojanovic, D. Aouada, and B. Ottersten. “Cost sensitive credit card fraud detection using bayes minimum risk”. In: Proceedings - 2013 12th inter- national conference on machine learning and applications 1 (2013), pp. 333–338. A. C. Bahnsen, A. Stojanovic, D. Aouada, and B. Ottersten. “Cost sensitive credit card fraud detection using bayes minimum risk”. In: Proceedings - 2013 12th Inter- national conference on Machine Learning and applications 1 (2013), pp. 333–338.


I am trying to install Gmsh in 12.04 x64:  xxx@sjb-linux:/320/installslinux/gmsh$ sudo apt-get install gmsh Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  gmsh : Depends: libmed1 (>= 3.0.3) but it is not going to be installed E: Unable to correct problems, you have held broken packages. xxx@sjb-linux:/320/installslinux/gmsh$    I have now tried all the advice I could get  sudo apt-get -f install sudo apt-get clean   with no success, these commands report absolutely no problem.  I'll appreciate help.


I am working on git repo which has no git flow setup means it does not have master, develop, feature branch. I cloned this repo and I have created a branch test_branch and I made changes on my local branch and did multiple commits then pushed them. Now, I would like to find out list of files I have pushed.   All the git diff commands I found are comparing with origin/master, HEAD and so but in my case this will not be available . I will push my changes by setting up an upstream like git push -u origin test_branch. In such scenario how can I find list of files which I have pushed?  I have tried following commands but not matching with my requirement   git log --name-only pattern="" git diff origin/master...   git log shows complete information on local branch but I need only files which I have pushed. After one git push I might do one more set of commits and doing git push I need only files which I pushed recently.   I am getting this error when I try with origin/master.  fatal: ambiguous argument 'origin/master...': unknown revision or path not in the working tree.  I am looking for a command which is purely depend on local branch to find out the pushed files.  EDIT:    will not solve my problem becuase,   I do not have commit ids I need list of files from multiple commits not from last or recent commit.


Identity/Conditional Relations, Fitch Calculus in Logic

I have two fallacious arguments written propositionally:   If P, then Q  If P, then R  Therefore: If Q, then R   And   If P, then Q  If R, then Q  Therefore: If P, then R   However, if these particular propositions were interpreted as being connected not by a conditional sign but by an "=" (identity) sign, wouldn't we have examples of the transitive property (i.e. P=Q, P=R, so Q=R using the rule of identity elimination in Fitch calculus)? However, neither conditional/biconditional introduction/elimination in Fitch would be able to prove this -- hence it being a fallacy. The Fitch rules to which I'm referring are these:    Is what I'm implying by using "=" that P, Q, R are the exact same proposition?


Do comment style notifications to @user work in answers too?

I would like to notify another user in an answer, like:     My solution was actually inspired by @John's answer...   Will this work?


How to evaluate $\int_0^1 \int_0^1 \frac{1}{1-u^2+v^2}dudv$?

For (i) I did it by turning the integrand into infinite series, but  what is the method by applying binomial theorem?  For (iii) I'm unsure as to a good "trigonometric substitution".


IPod Touch says it's disabled for 22,768,662 minutes

I have an iPod Touch that says it is disabled and to try again in 22,768,662 minutes.  I really don't have 42 years to wait.  I need to access this iPod Touch and the material inside it without factory resetting it.  Please help?


Amazing Follower Tweaks and Meeko: No option to leave service!

So I've downloaded the "My home is your home" mod so that my chosen followers will stay at my house when I don't need them. Before this mod I did not check if Meeko could leave my service, so I'm unsure if this mod is messing him up.  My two other follers, Sofia (John Jarvis and Christine Slagman) and Garm (Wolfgrimdark), both leave my service and stay where I tell them to. (when I speak to Garm he joins my service automatically, but he'll leave when I ask.) I am also using Meeko reborn to change Meeko to a white husky, so the issue may be related to this mod.   I've tried removing Amazing Follower Tweaks and the option pops up, but he won't join my service anymore. I was trying to get the kids to keep Meeko and apparently they don't recognize that you have a dog with the aft mod enabled, but I've given up on that issue because I can't get rid of him now.  Has anyone else had a similar problem or a fix? *my follower count is 0 and my animal count is 0  Edit: Ok so making a clean save with AFT does work and Meeko stays where I told him to! As long as I never ask him to join me ever again...


Height unmixed ideal and a non-zero divisor

Let $R$ be a commutative Noetherian ring with unit and  $I$ an unmixed ideal of $R$. Let $x\in R$ be an $R/I$-regular element. Can we conclude that $x+I$ is an unmixed ideal?   Background:  A proper ideal $I$ in a Noetherian ring $R$ is said to be unmixed  if the heights of its prime divisors are all equal, i.e., $\operatorname{height} I=\operatorname{height}\mathfrak{p}$ for all $\mathfrak{p}\in \operatorname{Ass} I$.


How do I convert blender render materials to cycles materials in 2.78c?

I have found the articles describing the python scripts to automatically convert, but the scripts seem to have been deleted, presumably because they have stopped working.  For example, looking for materials_cycles_converter.py in the diffusion browser produces the message "This path does not exist at rBAC89bfa619831c. It was deleted in 7d7b8c7d3efc and last existed at rBAC3f433bbe91fd." Is there an alternative script that I haven't found?  Or a tutorial?  -- edit: I originally mistakenly used 'textures' where I should have used 'materials' in the title.


I have a dictionary with the name of a circle arc and the location for the arc. I would like to use for loop to create all the arcs in the dictionary. When I run this code I can error TypeError: 'dict_keys' object does not support indexing  Here is the relevant code:  self.gaugeDict={"gauge1": [100,105,100],                                 "gauge2": [300,105,100],                                 "gauge3": [100, 210, 100],                                 "gauge4": [300, 210, 100]}         for i in range(len(self.gaugeDict)):             self.w.create_circle_arc(self.gaugeDict.keys()[i][0],                                      self.gaugeDict.keys()[i][1],                                      self.gaugeDict.keys()[i][2],                                      fill="black",                                      outline="",                                      start=180,                                      end=0)


Let $G(V, E)$ be an undirected final and simple graph. $\bar{G}(V, E')$ a simple graph on the same vertices, while $e \in E'$ iff $e \notin E$ Prove that if G is not a connected graph, then $\bar{G}$ is a connected graph.  This is my idea: Let $v_1, v_2$ $(v_1 \neq v_2)$ be vertices in $V$, assume there isn't such a route $v_1 \overset{e_1}{\rightarrow} ... \overset{e_m}{\rightarrow} v_2$, while $e_i \in E'$. therefore in particular $(v_1, v_2) \notin E'$, therefore $(v_1, v_2) \in E$. this is true for every $(v_1, v_2)$ in contradiction to G not being connected. Is this ok? I feel like there is something wrong here... *I translated it so if anything is not clear please tell me.


I would like to get an alert (with sound) when my laptop battery is fully charged.  How can I do that?


Non-standard British use of possessive "me"

Native North American speaker here.   It's fairly common in certain British dialects to substitute "me" for "my" (Shiver me timbers) in informal speech. My impression is that some speakers mix the two. What are the descriptive rules for selecting between the two variants? Specifically, I'm asking about usage of  A non-standard variant of my (particularly in British dialects) is me. (This may have its origins in the fact that in Middle English my before a consonant was pronounced [mi:], like modern English me, (while me was [me:], similar to modern may) and this was shortened to [mi] or [mɪ], as the pronouns he and we are nowadays; [hi wɒz] he was; versus [ɪt wɒz hi:] it was he. As this vowel was short, it was not subject to the Great Vowel Shift, and so emerged in modern English unchanged.)  () As an example, here is an excerpt from the character Daisy in Downton Abbey:  DAISYSomeone walked over me grave.  () Someone please supply a video clip of this speech pattern.   I'm sure it can be found, but I can't.


What is the correct setting of Nginx's fastcgi_param SCRIPT_FILENAME?

In  &  it is said that it should be:  fastcgi_param  SCRIPT_FILENAME    $document_root$fastcgi_script_name;   But in my Ubuntu (/etc/nginx/fastcgi_params), the setting is:  fastcgi_param   SCRIPT_FILENAME     $request_filename;   I am using the Ubuntu setting and didn't have any issue. What are the pitfalls?


Captions not directly below figure in minipage environment

So I wanted to show two pictures side by side, put captions below them and then replace some text inside.  This is what I have done:  \documentclass[a4paper,12pt]{article}   \usepackage{fullpage} \usepackage[utf8]{inputenc} \usepackage{amssymb, amsmath, amsthm} \usepackage{psfrag, graphicx}  \begin{document} \begin{figure} \centering \begin{minipage}[c]{.5\textwidth}   \includegraphics[width=1\linewidth]{convplot1}   \caption{first figure}   \label{fig:1} \end{minipage}% \begin{minipage}[c]{.5\textwidth}   \includegraphics[width=1\linewidth]{convplot2}   \caption{second figure}   \label{fig:2} \end{minipage} \end{figure}   \end{document}   I would like to have the captions show up right below, while using the minipage environment, but what it actually gives me is this:   I am not quite sure how to fix it, so any help is greatly appreciated!


As I am currently tutoring a calculus student, I am creating a mock exam in LaTeX. I have a question concerning a portion of my code which I have displayed below, though, I do not know if displaying my code helps at all in any way. (See the very bottom of this post for my question.)  \textbf{Integral Identities} (and some more Derivative Identities)  Write the identities for the following indefinite integrals or derivatives in problems 5-10. In this section, you are encouraged to consult your textbook or any resource available. \textit{No work is required to be shown.}  Do not forget about the $+C$ which is required for indefinite integrals!  \begin{enumerate} \item[5.] If $n$ is an integer, then $\displaystyle \int x^n \, dx=\begin{cases} \frac 1{n+1}x^{n+1}+C &\text{if }n \not= -1 \\ \ln|x|+C & \text{if }n = -1 \end{cases}$.   \textbf{Hint: }We must consider two cases here. \begin{itemize} \item If $n \not=1$, simply state the Anti-Power Rule, which is the exact opposite of the Power Rule which you saw in problem 1. Observe that the Anti-Power Rule does \textit{not} work if $n = -1$; try it anyway with $n=-1$ and you will see why it fails.  \item For the case of $n=-1$, refer to problem 4 for a hint. For whatever antiderivative you write in the second blank, place the absolute value bars around the $x$, like this: $|x|$. This is due to a mathematical technicality for the integration of $x^{-1}$. \end{itemize}  \item[6.]  Evaluate: $\displaystyle \int e^x \, dx = e^x+C$.  \item[7.] What are the derivative identities for the following? You may wish consult your textbook as necessary. (Yes, part i. was shown already in problem 3.) \begin{table}[h] \centering \begin{tabular}{ll} i. $\displaystyle \frac d{dx}(\sin x) = \underline{\hspace{4cm}}$ & ii. $\displaystyle \frac d{dx}(\cos x) = \underline{\hspace{4cm}}$ \\ iii.  $\displaystyle \frac d{dx}(-\sin x) = \underline{\hspace{4cm}}$ & iv.  $\displaystyle \frac d{dx}(-\cos x) = \underline{\hspace{4cm}}$ \end{tabular} \end{table}  \item[8.] What are the integral identities for the following? Use problem 7 for clues. \begin{table}[h] \centering \begin{tabular}{ll} i. $\displaystyle \int \sin x \, dx  = \underline{\hspace{4cm}}$ & ii. $\displaystyle \int \cos x \, dx = \underline{\hspace{4cm}}$ \\ iii.  $\displaystyle \int -\sin x \, dx = \underline{\hspace{4cm}}$ & iv.  $\displaystyle \int -\cos x \, dx = \underline{\hspace{4cm}}$ \end{tabular} \end{table}  \item[9.] What are the derivative identities for the following? \begin{table}[h] \centering \begin{tabular}{ll} i. $\displaystyle \frac d{dx}(\tan x) = \underline{\hspace{4cm}}$ & ii. $\displaystyle \frac d{dx}(\cot x) = \underline{\hspace{4cm}}$ \\ iii.  $\displaystyle \frac d{dx}(\csc x) = \underline{\hspace{4cm}}$ & iv.  $\displaystyle \frac d{dx}(\sec x) = \underline{\hspace{4cm}}$ \end{tabular} \end{table}  \item[10.] What are the integral identities for the following?   \begin{table}[h] \centering \begin{tabular}{ll} i. $\displaystyle \int \tan x \, dx  = \underline{\hspace{4cm}}$ & ii. $\displaystyle \int \cot x \, dx) = \underline{\hspace{4cm}}$ \\ iii.  $\displaystyle \int \csc x \, dx = \underline{\hspace{4cm}}$ & iv.  $\displaystyle \int \sec x \, dx = \underline{\hspace{4cm}}$ \end{tabular} \end{table}  \item[11.] Write the formula for this integral: $\displaystyle \int \ln x \, dx=         \underline{\hspace{4cm}}$. Use your textbook or some other resource if needed. (I probably     said this enough already, haven't I? :D)  \end{enumerate}  \newpage   I want the tables to correspond with my question numbers 7,8,9,10 respectively. The table for my question #10 is being stupid, and that table of integrals is instead outputted to the next page. Any possible reason why this is happening? As in, why is this table not appearing below question #10 as I wanted? I am so confused right now.


Getting a standard form quadratic from a set of points ($3$ points)

I came home from school today, pulled out my homework, now I'm stumped.  I don't want the answer, I just want to know how to do it.  Here is the question that I'm reading:  Determine a quadratic function in standard form for the set of points $(x_1,y_2)(x_2,y_2)(x_3,y_3)$  Where the $x$'s and $y$'s represent the points.  Here are the points I am working with (remember, I don't want the answer, I just want to know how to do it, there are lots of questions on this so I want to be able to know how to do it).     $(-1, 2), (0, 1), (1, -4)$   Thanks!


Find the coefficient of $x^r$ in the expansion of $e^{e^x}$.  My Attempt:  $$e^{e^x}= 1+\dfrac {e^x}{1!} + \dfrac {(e^x)^{2}}{2!} + \dfrac  {(e^x)^{3}}{3!}+......$$  How to proceed further?


Can't find where I made a computation mistake with calculating $\int_{0}^{1} \frac{dx}{(x^2+1)^2}$

I am trying to integrate the following integral:  $$\int_{0}^{1} \frac{dx}{(x^2+1)^2}$$  However, I am always getting the wrong answer in the end. What I have tried doing is the following: $$\int \frac{dx}{(x^2+1)^2} = \int \frac{1}{(\tan^2\alpha + 1)}\times \sec^2\alpha \text{ }d\alpha = \int \frac{1}{\sec^2\alpha}d\alpha =\int \cos^2\alpha \text{ }d\alpha$$ $$= \frac{1}{2} \int1+\cos(2\alpha) \text{ }d\alpha$$ Now, at this step I was trying to get $\alpha$ in terms of $x$ using the triangle. So I know that $\alpha = \arctan(x)$ and $\sin(2\alpha)=2\sin \alpha \cos\alpha = 2(\frac{x}{x^2+1})(\frac{1}{x^2+1})$. Upon substituting it back, I get that $$\int \frac{dx}{(x^2+1)^2} =\frac{1}{2}(\arctan(x)+\frac{x}{2(x^2+1)^2})$$ And when I try to find $\int_{0}^{1} \frac{dx}{(x^2+1)^2}$, I get: $$\int_{0}^{1} \frac{dx}{(x^2+1)^2} = \frac{1}{2}(\arctan(1)+\frac{1}{2(1^2+1)^2}) - \frac{1}{2}(\arctan(0)+\frac{0}{2(0^2+1)^2}) = 0.5177$$ However, the answer in the textbook is said to be $0.6427$ and interestingly enough, when I add a $2$ like so $$\int \frac{dx}{(x^2+1)^2} =\frac{1}{2}(\arctan(x)+\mathbf{2}\frac{x}{(x^2+1)^2})$$ I get the correct solution, which is quite odd since I based my solution on the fact that $$\frac{1}{2}\sin(2\alpha) = \cos(\alpha)\sin(\alpha)$$ So there should not be a $2$ there. I am probably missing something, which sadly I can't find...


This is a very basic sum of 5 floats. It's very obvious that the result is 1, so why does python shows me 0.9999999 when i print the result? sum([.25,.35,.3,.1,0]) # gives 0.999999(9)


Explanation for short proof, compactness of linear operator

Let $H$ be a Hilbert space and $\{\phi_k\}$ an orthonormal basis of $H$. Prove that the linear operator $T:H \to H$ defined by $T(\phi_k) = \frac{1}{k+1}\phi_{k+1}$ is compact.   Proof: Consider the sequence of linear operators defined by $$ T_n(f) = \sum_{k=1}^{n}\frac{1}{k+1}\langle f,\phi_{k}\rangle\phi_{k+1}.$$ They have finite rank, so they are obviously all compact.  Since $T$ is linear and $\phi_k$ is an orthonormal basis, $$ T(f)=T(\sum_{k=1}^{\infty}\langle f, \phi_k \rangle\phi_k) =\sum_{k=1}^{\infty}\langle f, \phi_k \rangle T(\phi_k) = \sum_{k=1}^{\infty}\frac{1}{k+1}\langle f, \phi_k\rangle \phi_{k+1}.$$  Then $$ \|(T-T_n)(f)\|^2 = \|\sum_{k=n+1}^{\infty}\frac{1}{k+1}\langle f,\phi_k \rangle \phi_{k+1}\|^2 = \sum_{k=n+1}^{\infty}\frac{|\langle f,\phi_k\rangle |^2}{(k+1)^2}\leq\frac{1}{(n+2)^2}\sum_{k=n+1}^{\infty}|\langle f,\phi_{k}\rangle|^2 \leq \frac{1}{(n+2)^2}\sum_{k=1}^{\infty}|\langle f,\phi_{k}\rangle|^2 = \frac{1}{(n+2)^2}\|f\|^2.$$  So $$ \|T-T_n\|=\sup_{\|f\|=1}\|(T-T_n)(f)\| \leq \frac{1}{(n+2)^2},$$ which tends to zero as $n \to \infty$.  My question is: Why does this prove what was asked? This proves that there is a sequence of compact operators that converges to $T$. How can we infer that $T$ is compact from that? Is there such a theorem?


I want to display an indoor map. My problem is that when I change to another floor (the URL changes) the tiles are not refetched. The following code is used:  var indoorSource = new ol.source.XYZ({     crossOrigin: null,     tileUrlFunction: parseUrl,     maxZoom: 45 }); var indoorLayer = new ol.layer.Tile({     source: indoorSource });   The parseUrl function is the following:  var parseUrl = function (tileCoords, pixelRatio, projection) {     var url = 'http://127.0.0.1/tiles/{z}/{level}/{x}/{y}';     var innerMap = LocalUserData.currentInnerMap();      url = url.replace('{level}', innerMap.level || 0);     url = url.replace('{z}', tileCoords.z || 0);     url = url.replace('{x}', tileCoords.x || 0);     url = url.replace('{y}', tileCoords.y || 0);     return url; };   Is there a way to force a reload of the tiles?


How can I get Rock Band 1 songs into Rock Band 2?

As I'm planning to buy Rock Band 3, but I wanted to buy Rock Band 1 & 2 first.  But off course I don't feel like swapping disks all the time and I heard you can actually import games from Rock Band 1 into Rock Band 2, but how do I do this?  Note: I own both a PS3 and a Xbox360, so feel free to answer the question for every platform


C#, Convert/Join List of arrays into single array

I have the following list of arrays var list = new List<string[]>();  how to use LINQ to convert/Join them into a single array string[] singleArray;


Removing files containing, only, one row?

I have large number of csv files saved within a folder. I would like to, only, delete the csv files that contains one row, how can I do that?


How to generate stackexchange pictures with profile information?

Time ago I saw a profile with an image like this one:    So I copied the image url but adapting it to my own user id and I put it in my  page. It has been a while and my reputation is still the same in the image, so I've realized that the url now is http://i.stack.imgur.com/2QkYT.png (I remember before was something like http://www.stackexchange.com/users/[my_user_id].png) I've been looking in the help section,another profiles, but no clue. Is still working this functionality? if so, what's the url to generate it? Is specified in some help site? FAQ?


Function whose graph is dense in the plane

Is there a function $f:\mathbb R\to\mathbb R$ such that for every disc in $\mathbb R^2$ the graph of that function has at least one point that lies inside that disc? I searched for something similar but don't know which phrases to use. The general/another problem is that: does there exist a function $f:\mathbb R\to\mathbb R$ such that its graph in some sense has a positive area or even an infinite area?


What's the difference between gravitational attraction and weight?

What exactly is gravitational attraction? In my textbook it was quoted " all objects both tiny and large objects are attracted to the earth. This is known as gravitational attraction, or the force due to gravity". But the force due to gravity is weight. I think that gravitational attraction is the action of attraction and is different from the force due to gravity (weight). Pls clarify.


I was about to merge my stackoverflow account...how to protect my points

I have somehow two accounts with my ID for stats.stackexchange.com The account linked with Stackoverflow has reputation of 1 while that connected with crossvalidated has rep (31+2B).   I guess this happend because I might have entered different email when creating account on crossvalidated. One has reputation 1 and the other has 31+2B.  How should I delete the one on stackoverflow and insert the one on crossvalidated (stats.stackexchange.com)? I just want to remove the redundancy.


Functional integral aproach for Feynman rules

I am familiar with the basic ideas of quantum field theory but I feel uncomfortable when I have to derive Feynman rules by myself for a given action  (for example in non-linear sigma models or electrodynamics). Could you provide a list of good books, articles, lecture notes and/or any other sources (except Peskin), where Wick's theorem and the Feynman rules are derived from the functional integral in detail, preferably with examples?


Can you diff all files in one directory?

I have a bunch of files stored in various directories. They have been created at different times, but I need to check that their contents are the same. I cannot find how to do a diff on ALL files in one directory. Is this possible or is another CLI tool required?


Is there any way to root Galaxy Tab A 9.7 (SM-P550) 6.0.1?

As far as I know Kingo  and CF-AUTO root are not compatible with the current time galaxy tab A. Any suggestions?  Side Note TWRP and CWM are not compatible with my device


How do you list the primary key of a SQL Server table?

Simple question, how do you list the primary key of a table with T-SQL? I know how to get indexes on a table, but can't remember how to get the PK.


I am trying to evaluate this limit but I am unsuccessful: $$ \lim_{n \to \infty} \frac{1+\sqrt[n]{e}+\sqrt[n]{e^2}+\cdots++\sqrt[n]{e^{n-1}}}{n}$$ I have to do it with Riemann sum (by converting it to a definite integral), but I am stuck. I wrote it like that (I hope that's correct): $$ \lim_{n \to \infty} \frac{1}{n} \sum_{k=1}^n \sqrt[n]{e^{k-1}} $$ I guess I should take the intervals to have length $\frac{1}{n}$, but I don't know how to find the function $f(x)$ to integrate. What bothers me the most is that $n$-th root that I don't know what to do with. I was also thinking of somehow applying $\ln$, but I don't know how.


Coalesce records in sql server when repeated two 2 times

I have records as follow in a tables on sql server 2005  fname  lname  address  zip  xxx    yyy     UK      001  zzz    yyy     UK      001  aaa    yyy     UK      002   ddd    jjj     US      003  eee    jjj     US      003    I need to get the result in the following format    fname    lname  address  zip xxx,zzz   yyy    UK      001 ddd,eee   jjj    US      003   Basically every records which have a count address and zip 2 times will have their first name grouped and separated by comma.   Ok Here is my approach: but not working and stuck right now  select fname, lname, address, zip from table people  where address is not null and zip is not null group by address,zip  having count(address)=2 and count (zip)=2  order by address   -- Now to coalesce the records I am using   SELECT fname = COALESCE(fname + ', ', '') + ISNULL(fname, 'N/A'), fname, lname,streetname, housenumber FROM people  WHERE address is not null and zip is not null   group by address,zip  having count(address)=2 and count (zip)=2  order by address


regex pattern to match first 2 numbers in a string

Can anyone help with this one please  I need a regex pattern to check the first 2 numbers match either 01 or 02 or 03 or 07 only


Partial Classes, LINQ, Interfaces and VB.NET

Okay, I have ran in to a problem with VB.NET. So all those defenders of VB.NET please can you help me out? Here is my issue: I am using LINQ to Entities, it also works with LINQ to SQL, I build my edmx file I then create a Partial Publc Class of the same name as one of the entities All fine up to now, so here comes the problem.   I need the Partial class to implement an Interface Implements Interfaces.IAsset But VB.NET want to place "Implements Interfaces.IAsset.ID" at the end of the property, which of course is in the generated code section of the Partial class, which I can not do as the edmx file is auto generated and will change in the future.   Here is the line of code that needs sorting:   Public Property ID1() As Integer Implements Interfaces.IAsset.ID   In C# it is fine and works wonders. So why can't VB.NET implement an interface that is in the code generated class?


Prove: Use the triangle inequality to prove that for all $x, y, z, | x − z | ≤ | x − y | + | y − z |$

Prove: Use the triangle inequality to prove that for all $x, y, z, |x-z|≤|x−y|+|y−z|$ Is my proof correct?  Proof: Let $a = x-y$, and $b=y-z$. We can say that $|a+b| = |(x-y) + (y-z)| = |x - z|$. Further more we can say: $$|a| + |b -a| \ge |a + b -a| = |b|$$ $$|b| + |a -b| \ge |b + a -b| = |a|$$ Move |a| to the right side in the first inequality and |b| to the second inequality. We get: $$|b +a| \ge |b| + |a|$$ $$|a +b| \ge |a| +|b|$$ From absolute value properties we know that $|b+a|=|a+b|$ Combining these two facts together we get: $$|a+b| \le |a|+|b|$$ Which implies $$|x − z | ≤ | x − y | + | y − z |$$  Or applying the triangle inequality directly we can also prove it this way:  Proof: Let $a = x-y$, and $b=y-z$. We can say that $|a+b| = |(x-y) + (y-z)| = |x - z|$. Substituting $a$ and $b$ into given inequality we get $$|a+b| \le |a|+|b|$$ which by claim is equivalent to the triangle inequality. QED.


Is there an archive for site newsletters?

I have been following some of the  and now I have time to review some of them. Is there any archive for old newsletters? They were stored and tagged in my Gmail. While there was thousands of them there it had made a bad view for my inbox, so I deleted them, unfortunately! Now, is there any way to find them on Stack Exchange?


Crouton is overlaying the toolbar on the StackExchange Android app

The Crouton should ideally display underneath the toolbar, for context-sensitive updates that don't block content actions.  I apologise if this is a double-post, because I think I initially submitted it to the wrong community.


What should be transfer learning model accuracy?

I have made base model for transfer learning and it is showing good accuracy, and even good confusion matrix is also showing good results Here is accuracy and losses for base model loss: 0.0566 - accuracy: 0.9767 - val_loss: 0.3767 - val_accuracy: 0.9613 For transfer learning model I am not able to show good accuracy but confusion matrix is excellent Here is accuracy and loss for transfer learning loss: 0.2698 - accuracy: 0.1914 My question is that, for transfer learning model should always less accuracy or should be more, do you think is there any problem ?


Schengen Visa Application: what are some helpful tips for preparing?

Lots of people would like to visit the EEA area to take holiday or to visit family or even to go for longer term visa arrangements in the Schengen zone.  In order to do this, they need a Schengen (or national) visa.  This appears to be a fairly straightforward process, but hints and tips can always be helpful.  Without focusing on any individual's circumstances, what are some helpful hints that can improve the likelihood of a successful application?


Today I have entered random float number and multipled by hundred firstly using normal code and then in console as was giving me wrong number, console is returning me the same.  The given float number is: 1050.6  Therefore: 1050.6 * 100 should be 105060, but javascript is returning me 105059.99999999999  Anyone knows why?


How to clear Vinagre recent connections?

How do I clear the items in Vinagre under Remote > Recent Connections?  I've done  and it does not work.  I've deleted the entire Vinagre profile directory ~/.local/share/vinagre and it somehow regenerates the recent connections list.  I uninstalled and reinstall Vinagre... still there!  Where the heck is this stubborn list stored that I can actually delete it?


I am an Indian. Can i go out from airport during my 20+ hours layover in London and visit places?

I am an Indian working in Thailand. I have to visit Spain in Feb 2017 and on the way, I may have a layover of around 15- 24+ hours in London. Am I allowed to pass emigration and go out in city to visit places or do  I need a Transit visa for my visit.


Pls explain what exactly this "Priority Seat" represents

I would like to understand what exactly this "Priority Seat" represents.    Image credit:   For a long time, I was thinking "Priority Seat" is the name of an adjacent  priority seat so that "A" is not required. Just like the name of your iPhones is "iPhone" not "an iPhone," But someone told me that "Priority Seat" is not a proper noun. The words are capitalized because it's a title.  Then I came up with a new explanation, that is, this "Priority Seat" is simply an abbreviated form of "A Priority Seat"; "A" is omitted because it is a sign. But when I imagine a sign that reads "A Priority Seat" in this context (adjacent to a priority seat) I feel so incorrect. The text wouldn't work to create the right nuance. So I had to drop this idea as well.   Could anyone explain what kind of grammatical structure is used for this "Priority Seat" so that I could clearly understand what it represents?


Is the shooter's face revealed in the Danish film Jagten?

The Danish movie Jagten (2012), a.k.a The Hunt, ends with Mads Mikelsen escaping from a shooter. I remember that when I saw the movie, they had shown the shooter to be his son. But according to ,      On a hunting expedition to commemorate the event, an unseen person   apparently shoots at Lucas and misses him. Blinded by the setting sun,   Lucas is unable to identify his attacker, who is apparently reloading.   A moment later the unknown shooter, real or metaphor, is no longer ther.   Could anyone tell me if there are two ending versions of the film, or am I wrong here?


Refund of Turkish Airlines Tickets for medical reasons

I was hospitalized and doctor didn't allow me to fly, shall I get the refund? It was Turkish Airlines. We were four in the family. Since I was not able to fly, they couldn't.


I am the only user on my PC and do not want to enter my password.  How do I disable?  I do not want to enter a password every time my screen saver starts or I install any aps.


Copy screenshot to clipboard in addition to saving the file

Within OS X 10.11.6, the  Cmd ⌘   Shift ⇧   4  key combination saves a screenshot to the desktop by default.  Is there a way to automatically copy the file to the clipboard (in addition to saving the file), so that the screenshot can be pasted into a document?  Maybe there is some clever why to tee and pipe the image to the clipboard?  The intent is to:    save screenshot to a file and  copy screenshot to the clipboard    with a single command.   Examples are always appreciated.


Clicking on tags in global search results is broken

If you search for something on "all sites" (using the searchbox at the top of , you'll reach the search results, e.g.  .  If you click directly on a tag on that page, e.g.        You get 404 Page Not Found error, e.g.     Steps to reproduce   Go to  and enter e.g. "keyforge" into the "Search all sites" field. Arrive at  Click on the "keyforge" tag below a search entry. Reach  (404 page not found)   Expected behaviour  Reach   System Info  Happens in both Firefox and Vivaldi browsers on Windows 10.


This is quite easy to do if we do the middle term splitting method, but here's another method given in the book:   Only considering terms with powers of $x$ and constants: $-3x^2 + 11x - 6 = (3x - 2)(-x + 3)$    Only considering terms with powers of y and constants: $8y^2 - 8y - 6 = (-4y - 2)(-2y + 3)$    Merging both we get $-3x^2 - 2xy + 8y^2 + 11x - 8y - 6 = (3x - 4y - 2)(-x - 2y + 3)$     Why does this method work, and is there a name to this method?


I'm trying to build a command that displays a sort of checklist. Ideally, I only want to pass a set of boolean values to that command.  A naive MWE looks like this:  \documentclass{article} \usepackage{tabularx}  \newcommand{\mychecklist}[5]{     \begin{table}         \begin{tabularx}{\textwidth}{|l|l|}             param 1 & #1 \\             param 2 & #2 \\             param 3 & #3 \\             param 4 & #4 \\             param 5 & #5         \end{tabularx}     \end{table} }  \begin{document} \mychecklist{x}{}{x}{}{x} \end{document}   However, I need to pass more than 9 parameters. How can I do this efficiently? Is there a solution that lets me pass a set of indices (eg. [1,3,5]) to the command and produce the desired result, a table with checkmarks in the respective positions?


Let $A$ a infinite set, and $a$ the cardinal number of $A$, then $a.a=a$ My attempt: We know $a.a=card(A\times A)$ and $card(A)=a$, then we need prove $card(A\times A)=card(A)$  Let $f:A\times A\rightarrow A$ such that $f(x,y)=x$ with $x,y \in A$ this is a bijective function and this implies $card(A\times A)=card(A)$  is correct this?


"learn to [verb]" "learn how to [verb]"   Is [1] merely a less formal version of [2]? If not, does [1] communicate something subtly different? Consider the following:  In [2], the object of learning is explicitly "how to [verb]" (for instance, "I will learn how to speak French").  Is the object of learning in [1] "to [verb]" or is it something implicit and abstract that allows the subject "to [verb]"? For instance, in "I will learn to speak French", the object of learning would be the prerequisite elements for speaking French: "French phonemes, grammar, syntax, etc.".


Why are the power transmission/distribution systems AC and not DC?

Is there a good reason why we are not in the process of completely converting our electrical transmission system to DC? The main reason for using AC on the grid (no offense Tesla, I love you man) was to enable transformation to higher voltages in order to drop line losses (\$P=IE=I^2R\$) and if the conductor size remains the same, when \$E\$ is increased in the equation \$E=IR\$ then \$I\$ must necessarily decrease, in turn decreasing losses as the square of \$I\$). But now we have the ability to transform AC (at all thermal, hydro and wind generators) and DC (at solar generators) to any level of DC we desire and transmit, usually to residential or commercial loads which tend to use DC anyway. If need be it can be converted back to AC at industrial loads (motors usually).  In this way many transformers, capacitors, spacing issues, etc. can be eliminated from the electrical grid, increasing efficiencies dramatically, and in turn decreasing emissions and costs.  Am I missing something here?


How are base class constructors called in c++

I am new to c++ I have 2 queries regarding how a base constructor is called.  1.) Lets say my code looks somewhat like this.  #include<iostream> using namespace std;  class Base  { public:     Base()    { cout<<"Constructor: Base"<<endl; }     virtual ~Base()   { cout<<"Destructor : Base"<<endl; } };  class Derived: public Base { public:     Derived()   { cout<<"Constructor: Derived"<<endl; }     ~Derived()  { cout<<"Destructor : Derived"<<endl; } };  int main()  {     Base *Var = new Derived();     delete Var;     return 0; }   I was told that a base constructor has to be called explicitly before defining the derived constructor by initialization list. But here without any call to the base constructor, the code is working as expected.  **The output for the above problem is**  Constructor: Base Constructor: Derived Destructor : Derived Destructor : Base   2.) Now suppose the base class constructor takes parametrized arguments, but the derived constructor is empty. In the main function, I declare a derived object without any argument to the constructor. what will happen? Any way to separately pass the base constructor of that object an argument?  Thanks.


Correct way to detect sequence parameter?

I want to write a function that accepts a parameter which can be either a sequence or a single value. The type of value is str, int, etc., but I don't want it to be restricted to a hardcoded list.  In other words, I want to know if the parameter X is a sequence or something I have to convert to a sequence to avoid special-casing later. I could do  type(X) in (list, tuple)  but there may be other sequence types I'm not aware of, and no common base class.  -N.  Edit: See my "answer" below for why most of these answers don't help me. Maybe you have something better to suggest.


how to do a Testing on an Already Installed Android application using Appium + Selenium ?

is there any way to test an application which is already installed For Eg. i want to test the calculator or google map application ?  my Current Appium version is 1.3.4.1


How can I copy the text of an unreportable error?

Occasionally I receive an error report from Ubuntu with the option to send in the details of the error. However, if the error was generated from a non-official package (local installation or PPA) I cannot just click submit to send in the error.  How can I copy all the error details so that I can manually submit them to the appropriate project?


Prove that  for $ R \gt 0, \quad \int\limits_0^\frac{\pi}{2}e^{-R\sin\phi}\,d\phi \lt \frac{\pi}{2R}(1-e^{-R})$ It seems that the intermediate value theorem doesn't work here. A tried to use $x=R\cos\phi,\; y=R\sin\phi$, and thus $\int\limits_0^\frac{\pi}{2}e^{-R\sin\phi}\,d\phi = \int\limits_0^1\frac{e^{-y}\,dy}{x}$, but now both x and y depends on $\phi$ and I don't know what to do next.


Why do electrons, according to my textbook, exist forever?

Does that mean that electrons are infinitely stable? The neutrinos of the three leptons are also listed as having a mean lifespan of infinity.


Can you grapple/shove with the Hunter Ranger's Whirlwind Attack?

The  states:     You can use your action to make a melee attack against any number of creatures within 5 feet of you, with a separate attack roll for each target.   The rules on "" state (the rules in shoving are effectively identical):     When you want to grab a creature or wrestle with it, you can use the Attack action to make a special melee attack, a grapple. If you're able to make multiple attacks with the Attack action, this attack replaces one of them.   I couldn't find any other features spells or abilities that allow a creature to make a flat "melee attack". If they had said "melee weapon attack" instead this would have meant the same thing but specifically have excluded grapple/shove as an option.  I am unsure whether the rules on grappling/shoving mean that the only time you can grapple/shove are when you take the Attack action, which you are not doing when using the Whirlwind Attack feature.   I would like answers to assume that the following ruling made in the  is correct:     Whirlwind Attack is unusual, in that it’s a single attack with multiple attack rolls...


I wanted to just confirm how much the size of Swap partition should be. Lots of places tell that the swap size should be twice the size of RAM. Somebody also told me that it shouldn't be more than 8 GB.If twice the size of RAM is more than 8 GB how big should the Swap partition be?


Start up applications in different workspaces

I want to start some applications when I turn on my computer.  For example, open Sublime in workspace 1 and Chrome in workspace 2 and so on.  I know how to use startup applications in Ubuntu but I have no idea about open them in different workspaces.


How to prove that $\{\land,\lnot\}$ is complete?

I am curious one one would prove that a set of operators is "complete," which to my understanding means it can be used to represent all possible truth tables.  So normally if we had $\{\land,\lor, \lnot\}$ and a truth table what I do is look at where the outputs are true and then chain the expressions together with ors. For example in the truth table for XOR the output is true when either $p$ or $q$ is true but not both, so $(p \land \lnot q) \lor (\lnot p \land q)$.  Using this approach I think you can do it for any truth table so $\{\land,\lor, \lnot\}$ is complete.  Now let's say you want to show that some other set of operators are complete. Does it suffice to show that you can synthesize the $\{\land,\lor, \lnot\}$ operators?  For example let's say you asked me to prove:   Is $\{\land, \lnot\}$ complete? We can synthesize the missing "or" operation in terms of these two with with $p \lor q = \lnot(\lnot p \land \lnot q)$ Is $\def\nand{\barwedge} \{\nand\}$ (NAND) complete? Assuming $p \nand q$ is the same as $\lnot(p \land q)$ I can say $\lnot p = \lnot p \lor \lnot p = \lnot(p \land p) = p \nand p$, and then $p \land q = \lnot(\lnot(p \land q)) = \lnot(p \nand q) = (p \nand q) \nand (p \nand q)$. And if we absolutely needed $\lor$ we could just copy our example from earlier in terms of NAND: $p \lor q = \lnot(\lnot p \land \lnot q) = \lnot p \nand \lnot q = (p \nand p) \nand (q \nand q)$.   Am I way off base or is this a valid way to prove completeness? First by showing $\{\land,\lor, \lnot\}$ is complete via the process in my second paragraph, and then in the future, showing that any arbitrary set of operators can be used to synthesize $\{\land,\lor, \lnot\}$ (or if we wish to be minimal, $\{\land, \lnot\}$)?


How to use PCs' internet connection on Android phone?

How to use PCs' internet connection on Android phone ? I want to use it for surfing and downloading apps from Google Play . Reverse tethering works for surfing but not for downloading apps . Device - Galaxy S running on Cyanogenmod 7.1 .   Windows 7 . Broadband internet connection . No router/wifi on pc .


Transluscent leaf using principled shader

I this setup as shown in the screenshot. The image transparency plugs into the mix factor, the transparent and principled nodes plug into the mix shader inputs. I'm trying to figure out how to introduce translucency into the setup. Any help would be appreciated.


Constant Internal energy of universe and its original source

While  I was studying thermodynamics I am confused about internal energy of universe.   here a question confused me. "If the internal energy of the universe is constant then where did all energy come from originally?" I would like to thank the person who explained it to me thanks for your help!!!


I don't always answer myself, but when I do, I fail to ask a good question

Sometimes I'll encounter problems while coding, or sometimes out of simple interest for a question, I'll google for an answer, and most of the time I find that answer is here on stackoverflow.com.   If I can't find an answer, or if it's not enough to satisfy my curiosity, sometimes I expend my own effort to solve those questions. And after I've solved it, I'm happy to make my contribution to the community, and I post them as the Q&A style posts. For example:     It seems relatively easier to ask a question if I didn't already have a solution, and I can put what I have so far in the question body, such as:     The problem to me is, if I have my own solution to my own question, then most of what I have so far becomes part of the solution. It's likely I have failed in making my contribution by asking a question to which I have an answer, for example:     So I'm wondering if there are some guidelines or good practices for Q&A style posts?   How do I do it better?


I know that we don't have automatic login for the Data Explorer, but what's with the automatic timeout/logout?  There have been times that I am logged into the site, maybe I walk away for a little bit, and I come back to being logged out.    Is there a reason for logging us out of Data Explorer?  If so, is it possible to either remove the timeout or extend the period of time before timeout?


I am trying to write Test for this class (Java Spring Boot):   Specifically, I am trying to Mock this method call:  URI uri = util.getServiceUrl("product");   To do this, I tried to instantiate a Mock of the ServiceUtils object and use the .when and .thenReturn Mock methods.  private ProductCompositeIntegration productIntegration = new ProductCompositeIntegration();      @Autowired     private RestTemplate restTemplate;      @Mock     private ServiceUtils util;      private MockRestServiceServer mockServer;      @Before     public void setUp() {         MockitoAnnotations.initMocks(this);         mockServer = MockRestServiceServer.createServer(restTemplate);     }      @Test     public void myTest() {         URI uri = URI.create("TestUrl");         Mockito.when(util.getServiceUrl("product")).thenReturn(uri);         ResponseEntity<Product> product = productIntegration.getProduct(1);     }   But I am still getting the result of the original object of ServiceUtils instead of the Mocked method call result.  What am I doing wrong?


I've been given the question of showing that no group of order $400$ is simple. I've tried to attack it via the Sylow theorems for about a week now, but all the tricks and methods I know seem to be failing horribly.  Things I've tried:  Trying to produce a contradiction by giving a map into $S_n$ by elements acting by conjugation on Sylow 5-subgroups doesn't work, since there are 16 such Sylow 5-subgroups, and 400 divides $16!$, so it might very well be an injection and therefore we can't obviously find a nontrivial kernel.  Trying element counting is messy and I can't get it to come out the way I want- for instance, we can show that each of the Sylow 5-subgroups is isomorphic to $\mathbb{Z}_5\times \mathbb{Z}_5$, so there should be at least 125 elements of order divisible by only 5, but I can't see this producing a contradiction with any of the  things I can find out about Sylow 2-subgroups.  Anyways, I'm probably missing something fairly obvious, and I would appreciate any hints, solutions, or other help that you could give.


when you see the math expression 4^(1/2) , how do you know if it means to give just the positive answer, or both positive and negative answers

So, is $4^{1/2} =$ just $+2$ , or is it $+2$ and $-2$ ? In high school I learnt that it was just $+2$. i see already in the 1st answers to my questions that this is a startlingly difficult question to answer!  normally in maths, there is no such ambiguity, and i would like to understand what sort of symbology should be used to remove the ambiguity of this. Note that i came to this question originally from having found issues in this matter in complex numbers. there i came across the expression "Principle Root", perhaps for strictly clear math symbology, a little plus suscript for that might be  what is needed to indicate that root? And if you expect 2 answers (is ALL the roots, rather than the one with the largest real component), what symbology would you use then to make that clear?  i am looking for a general rule here, the power of a half is a simple case.  what if it was power of some other fraction?  how should the question be expressed so as to indicate if the principle root is requested, or all roots?


Problem with alpha channels in my picture (PyGame)

Currently, I'm trying to paste a picture to my pygame game and this picture have a alpha channel (as you can see bellow this sentence).  But, for some reason, when I use convert() or convert_alpha(), it's not putting correctly the picture with the alpha channel on the game... Even when I tried to do some mainpulations of the picture, nothing.  Here is the code I tried to write (with the manipulations for alpha channel that it didn't worked) : class Spritesheet:     # utility class for loading and parsing spritesheets     def __init__(self, filename):         self.spritesheet = pygame.image.load(filename).convert()      def get_image(self, x, y, width, height):         # grab an image out of a larger spritesheet         image = pygame.Surface((width, height))         image.fill(pygame.color.Color("black"))         image.blit(self.spritesheet, (0, 0), (x, y, width, height))         image.set_colorkey(pygame.color.Color("black"))         return image  How can I put a picture who have originally the alpha channel on it?


Example of modules that are projective but not free; torsion-free but not free

Free modules are projective, and projective modules are direct summands of free modules.      Are there examples of projective modules that are not free?    (I know this is not possible for modules of fields.)  Free modules are torsion-free. But is the inverse true?      Are there examples of torsion-free modules that are not free?   Thank you~


If $M/N\cong M$, can we conclude that $N=0$?

Let $M$ be an $R$-module, where we may assume that $R$ is an integral domain.  Let $N$ be a submodule of $M$.  Suppose that $M/N\cong M$. Can we conclude that $N=0$?  (If no, what are some sufficient conditions that make it true?)  Update: I learn that for "infinite dimensional" cases it can fail. How about when $M$ is finitely generated, does it work?  Thanks a lot.


Centering \vdots in a system of modular equations

I want to centering \vdots with \equiv in a system of modular equations. And I tried to use mathrel{\makebox[\widthof{=}]{\equiv}} like . But XeLaTeX said ! Extra }, or forgotten $. \@settodim #1#2#3->\setbox \@tempboxa \hbox {{#3}}                                               \dimen@ii =\z@ \@tf@r \res... l.238   \end{frame}                 ! Missing number, treated as zero.  My full text: \[   \begin{cases}     x \equiv a_1 &\pmod{m_1}\\     \mathrel{\makebox[\widthof{\equiv}]{\vdots}}\\     x \equiv a_n &\pmod{m_n}   \end{cases}  \]  And I tried to type ≡ manually, but XeLaTeX can't display it. Any ideas?


Should multiverse theories be rebranded as meta physics?

I answered a question here with a quote with the following quote from Cosmologist George Ellis.     “Similar claims [about a multiverse] have been made since antiquity by many cultures. What is new is the assertion that the   multiverse is a scientific theory, with all that implies about being   mathematically rigorous and experimentally testable. I am skeptical   about this claim. I do not believe the existence of those other   universes has been proved—or ever could be. Proponents of the   multiverse, as well as greatly enlarging our conception of physical   reality, are implicitly redefining what is meant by ‘science.’”—pg 39      “For a cosmologist, the basic problem with all multiverse proposals is the presence of a cosmic visual horizon. The horizon is   the limit to how far away we can see, because signals traveling toward   us at the speed of light (which is finite) have not had time since the   beginning of the universe to reach us from farther out. All the   parallel universes lie outside our horizon and remain beyond our   capacity to see, now or ever, no matter how technology evolves. In   fact, they are to far away to have had any influence on our universe   whatsoever. That is why none of the claims made by multiverse   enthusiasts can be directly substantiated.”—pg 40-41      “A remarkable fact about our universe is that physical constants have just the right values needed to allow for complex structures,   including living things. Steven Weinberg, Martin Rees, Leonard   Susskind and others contend that an exotic multiverse provides a tidy   explanation for this apparent coincidence: if all possible values   occur in a large enough collection of universes, then viable ones for   life will surely be found somewhere. This reasoning has been applied,   in particular, to explanation the density of the dark energy that is   speeding up the expansion of the universe today. I agree that the   multiverse is a possible valid explanation for the value of this   density; arguably, it is the only scientifically based option we have   right now. But we have no hope of testing it observationally.”—pg 42      “All in all, the case for the multiverse is inconclusive. The basic reason is the extreme flexibility of the proposal: it is more a   concept than well-defined theory. Most proposals involve a patchwork   of different ideas rather than a coherent whole. The basic mechanism   for eternal inflation does not itself cause physics to be different in   each domain in a multiverse; for that, it needs to be coupled to   another speculative theory. Although they can be fitted together,   there is nothing inevitable about it. … Nothing is wrong with   scientifically based philosophical speculation, which is what   multiverse proposals are. But we should name it for what it is.”—pg 43   Now with this in mind if these theories cannot be independently verified should their truth not lie in  method outside physics or what is also known as meta physics?


I really like the hats game. But I would love to keep the hats longer then only one winter. I want to leave them in my wardrobe during summer. Last year, I collected some cool hats, and I apparently lost them during summer.  Maybe we could make a system that allows hats to last for about 2 or 3 years, so we don't have to start over each winter. Or even specify per type of hat a number of years they last? Very very rare hats could last for ever.  I asked this, simply because I love hats! :D


When you have a  on the battlefield      Whenever a creature with power 4 or greater enters the battlefield under your control, put a +1/+1 counter on Kronch Wrangler.   and a  enters the battlefield      When Bloom Hulk enters the battlefield, proliferate.    which ETB effect goes onto the stack first?  Are the triggers simultaneous, so I as an active player can choose to give my Kronch Wrangler a counter, and then proliferate it?


How specific does the trigger for a readied action have to be?

Let's suppose I'm a wizard casting a ranged spell. An enemy is behind cover but I suspect he'll come out, so I ready an action to cast at him when he comes out; but I don't want to risk getting charged at by another enemy and losing concentration or taking disadvantage. Can I say:  "I ready a spell. When that guy over there leaves cover, or when any enemy gets within 5 feet of me, I will cast it on that enemy"?


How should one maintain and update a MiKTeX installation?

Every once in a while after updating MiKTeX, the installation gets into an inconsistent state. This might be a problem with the packages (an example is described in ), but sometimes packages are split or renamed. The cases I remember are when  and when miktex-etex-base-2,9 was renamed to miktex-etex-base-2.9 (if I recall correctly; I am sure it was either that or something very similar). In each case the MiKTeX Update process suggested to remove the "old" packages but it didn't give the user any hints about him having to manually add the respective replacement packages back in the package manager to get one's MiKTeX installation back into a usable state.  What are best practices for keeping MiKTeX up to date? Note that I'm not asking about installing new packages or fonts in general; there are other questions covering this area.   In which order should one execute the Update process and the Synchronization of the repository? , it is recommended to check the MiKTeX homepage before updating. What else should one do? When and in which order (and why) should one execute the "Refresh FNDB" and "Update Formats" processes within the MiKTeX Options menu? What else can happen? Other advice?


FileWriter doesn't write integers into file

I am trying to read 2 input files containing integers(even duplicates are considered) and trying to find common integers and write them to the output file. input1.txt 01 21 14 27 31 20 31  input2.txt 14 21 27 08 09 14  Following is the code I tried: public static void main(String[] args) throws NumberFormatException {         try {             BufferedReader inputFile1 = new BufferedReader(new FileReader(new File("src/input1.txt")));             BufferedReader inputFile2 = new BufferedReader(new FileReader(new File("src/input2.txt")));             FileWriter fileCommon = new FileWriter("src/common.txt");             String lineInput1;             String lineInput2;             int inputArray1[] = new int[10];             int inputArray2[] = new int[10];             int index = 0;             while ((lineInput1 = inputFile1.readLine()) != null) {                 inputArray1[index] = Integer.parseInt(lineInput1);                 index++;             }             index = 0;             while((lineInput2 = inputFile2.readLine()) != null) {                 inputArray2[index] = Integer.parseInt(lineInput2);                 index++;             }              for (int a = 0; a < inputArray1.length; a++) {                 for (int b = 0;b < inputArray2.length; b++) {                     if(inputArray1[a] == inputArray2[b]) {                         fileCommon.write(inputArray1[a]);                     }                 }             }             inputFile1.close();             inputFile2.close();             fileCommon.close();          } catch (IOException e) {             e.printStackTrace();         }     }  I don't understand where I am making mistake. I am not getting any errors and the output file that is generated is empty. output expected are common integers in both files 14 21 27


Is the submodule of a finitely generated free module finitely generated?

$R$ is a commutative ring with unit and $M$ is a finitely generated free $R$-module. Is the submodule of $M$ also finitely generated?


I am trying to write a formula for opportunities but I keep getting the following error   Error: Syntax error. Extra ','  Here is my formula       IF      (TODAY() > CloseDate && TEXT(StageName)='Donation Likely')     ||      (TODAY() > CloseDate && TEXT(StageName)='Donation Prospecting'),"Past                   Due","Expecting")


What does "causally connected" or "causes" really mean?

In a different thread, a user stated the following about events preceding or following other events:     However, if the two events are causally connected ("event A causes event B"), the causal order is preserved (i.e. "event A precedes event B") in all frames of reference.   My question is what does "causally connected" really mean? What does "causes" mean? Further, given that we know that we can have instantaneous effects in typical quantum processes (e.g. flip the polarizer, effect on another a reading light years away, even though we cannot transmit useful information with this), does that not constitute "causing" for the purpose of this statement?


I'm trying to understand how the AES S-Boxes are calculated. I understand how the multiplicative inverse is calculated over $GF(2^8)$, but I'm confused by the description of the affine transformation. I haven't been able to Google a good explanation of how the S-Box values are calculated. Can someone explain how this works, starting after the calculation of the multiplicative inverse?


When I attempt to install pipelight, an error message displays on the terminal:   Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  pipelight-multi : Depends: ttf-mscorefonts-installer but it is not installable E: Unable to correct problems, you have held broken packages.  I follow these directions:   sudo add-apt-repository ppa:pipelight/stable sudo apt-get update sudo apt-get install --install-recommends pipelight-multi sudo pipelight-plugin --update   When I attempt to enter the third command, it then displays that error above. I've been using Ubuntu for a few days now so, I'm still getting acclimated with everything. Any suggestions or tips would be very helpful.   Thank you.


Property(with no extra processing) vs public field

Whenever there is question about credibility of Properties, I see that most of the discussion happens around functions/methods vs properties. But I would also like to know the compelling reason to use property with associated private field vs public field directly itself, incase of most common get/set behaviors with no other processing, I mean this way  public string CustomerName;   vs  private string customerName; public string CustomerName { get{return customerName;} set(string value){this.customerName=value;} }


Should eCommerce categories with pagination get noindex beyond the first page?

I have an eCommerce website and most of the categories have multiple pages.  I have ran an SEO check on seobility which mentioned duplicate content and pages fighting with each other for the same keywords. When  checked, the duplicate content and pages weighting where of the same category just different pages.  ie...    example.com/category/ example.com/category/page2/ example.com/category/page3/   I have the option to noindex extra pages but was wondering if this was worth doing?  My concern is that it may limit exposure of certain products which may appear on deeper pages.


"Not equal to" sign Alt code in a plain text editor

What is the ≠ sign Alt code to type in a plain text editor, for example a textarea? I've already tried Alt+2260 to no avail. Is it possible without touching the Registry settings?


Connecting two nodes from different forest trees

I want to draw the following figure without pstricks:    What I have is the following code:  \documentclass{minimal}     \usepackage{forest}  \usepackage[external]{adjustbox}   \newcommand{\menge}[1]{% \mbox{% $% \left\{% \ignorespaces#1% \right\}% $% %\\[-1.5mm] }% }   \forestset{ tag/.style={for tree={parent anchor=south, child anchor=north,align=center,base=top}}, % a style that creates an arrow pointing to the substitution node from a tree top node encoded as daughter  substitution/.style={edge={<-,dashed},l+=\baselineskip}}  \begin{document}  \menge{ \adjustbox{valign=c}{% \begin{forest} tag [S         [NP$_1^1\downarrow$]         [S,name=s1]] \end{forest} } \hspace{1cm} \adjustbox{valign=c}{% \begin{forest} tag [S,name=s2         [NP$_1^1$                 [e]]         [VP                 [NP$_1^2\downarrow$]                 [S*]                 [V$_1$                         [versprach]]]] %\draw(s1.south)--(s2.north); \end{forest} } }  \end{document}   I think connecting two nodes would be the logically correct way to do this, but the scope of the node naming ends with the forest environment, doesn't it. Is there another way to do this?


Find the value of $\sum_{n=0}^\infty\frac{1}{9n^2+9n+2}$

I was doing some problems in algebraic number theory and this series came up  $$\sum_{n=0}^\infty\frac{1}{9n^2+9n+2}.$$  So, I would like to know the value of this series. However, I don't want a full answer, only hints. I have tried to use Fourier's series, but with no success, perhaps an answer can be gotten usign this.  Thanks


When using SO's code blocks, can you control how syntax highlighting is performed? Many times, I've pasted (for example)  into an SO answer, and the syntax highlighting has been completely unrelated. Is there any way to turn it off, or to change the language used?


Convergence/Divergence of $\sum_{n=1}^{\infty} \sin(1/n)$

it is a question Convergence/Divergence of calculus II! Please give me a hand!  Determine convergence or divergence using any method covered so far.  $$\sum_{n = 1}^{\infty} \sin (1/n)$$


How to preview or 'peek inside' file from within Files explorer

In macOS, I think pressing the spacebar lets you preview the file's contents before opening it. Is there a way to do the same in Ubuntu? (i.e. quickly open and close a preview of the file)  I've seen , but I'd like to use default software and not have my screen space permanently occupied by a preview bar.  Adding tags to this message, I see mention of Gnome Sushi and Gloobus-Preview. I will try to search more about these items.


It is the default version of the imagemagick program convert that comes with ubuntu 14.04  ip-173-31-35-119:~ [prod]$ convert -version Version: ImageMagick 6.7.7-10 2014-03-06 Q16 http://www.imagemagick.org Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC Features: OpenMP      In another shell I have downloaded the latest version of source code and compiled locally.  If I start a new shell, I can see  $ bash - ip-173-31-35-119:~$ convert -version Version: ImageMagick 6.9.2-3 Q16 x86_64 2015-10-07 http://www.imagemagick.org Copyright: Copyright (C) 1999-2015 ImageMagick Studio LLC License: http://www.imagemagick.org/script/license.php Features: Cipher DPC OpenMP  Delegates (built-in):    So the new binary is already available.  In both shell, they report the same result from which and ls -l:  $ which convert /usr/local/bin/convert ip-173-31-35-119:~ [prod]$ ls -l /usr/local/bin/convert -rwxr-xr-x 1 root root 6336 Oct  7 20:11 /usr/local/bin/convert   Why the first shell seems to still running the old version of the binary? How can I clear this?


Is it true that the derived series of $G/G^{(n-1)}$ is of length $n-1$, where $n$ is the length of the derived series of $G$?

Consider a group $G$ and its derived series $$G=G^{(0)}\trianglerighteq G^{(1)} \trianglerighteq \ldots \trianglerighteq G^{(n-1)} \trianglerighteq G^{(n)}=\{1\}\,.$$ Is the derived series of $G/G^{(n-1)}$ is of length $n-1$? At first, I thought that it was clear because I thought that the derived series of $G/G^{(n-1)}$ was $$G/G^{(n-1)} \trianglerighteq G^{(1)}/G^{(n-1)}\trianglerighteq G^{(2)}/G^{(n-1)}\trianglerighteq \ldots \trianglerighteq G^{(n-1)}/G^{(n-1)}=\{e\}$$ But I'm not so sure if this is correct.


I connected my Oracle database to ArcGIS and added one layer to map. This layer has points and polygons. I make a selection in this layer and get 9508 selected features, which I want to export as shapefile and add it separately to the map. I choose Data > Export Data, choose to export only selected features. But in the shapefile I get, there are less objects that were selected - only polygons, not points.   How can I properly create such layer file with selected points and polygons from Oracle database layer?


I am working on  problem 3 from MIT's Fall 2010 OCW class 6.042J. This is covered in  which is about recurrences.  Here is the problem:  $$A_0 = 2$$ $$A_{n+1} = A_n/2 + 1/A_n, \forall n \ge 1$$  Prove   $$A_n \le \sqrt2 + 1/2^n,  \forall n \ge 0$$  I have graphed the recurrence and the upper bound and they seem to both converge on $\sqrt2$.    Also, if you ignore the boundary condition $A_0 = 2$ then you find that $\sqrt2$ is a solution to the main part of the recurrence. i.e. $\sqrt2 = \sqrt2/2 + 1/\sqrt2$.  The chapter and videos on recurrences have a lot to say about a kind of cookbook solution to divide and conquer recurrences which they call the Akra-Bazzi Theorem. But this recurrence does not seem to be in the right form for that theorem. If it were in the form $A_{n+1} = A_n/2 + g(n)$ then the theorem would give you an asymptotic bound. But $1/A_n$ is not a simple function of $n$ like a polynomial. Instead it is part of the recurrence.  Also, the chapter has a variety of things to say about how to guess the right solution and plug it into an inductive proof, but I haven't had much success. I have tried possible solutions of various forms like $a_n = \sqrt2+a/b^n$ and tried solving for the constants $a$ and $b$ but to no avail.  So, if someone can point me in the right direction that would be great. I always assume that the problem sets are based on something taught in the videos and in the text of the book but I am having trouble tracking this one down.  Bobby


Non-static method cannot be referenced from a static context .setRetryPolicy

Some kind guy gave me an answer to my question by posting code, however it isn't complete from the looks of it. I think its supposed to be a short timed-out kinda function, but it says "Non-static method setRetryPolicy (com.android.volley.RetryPolicy)' cannot be referenced from a static contex"  I don't exactly know how to fix this myself, so I'd really appreciate if someone had a quick fix for this. Here is the code;   RegisterRequest registerRequest = new RegisterRequest(username,password,isadmin,responseListener,errorListener);                 int socketTimeout = 500000;//30 seconds - change to what you want                 RetryPolicy policy = new DefaultRetryPolicy(socketTimeout, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);                 StringRequest.setRetryPolicy(policy);                 // Creating RequestQueue.                 RequestQueue queue = Volley.newRequestQueue(CreateUser.this);                  // Adding the StringRequest object into requestQueue.                 queue.add(registerRequest);   It gives that error at in the 4th line. This is also a continuation of my previous questions on trying to make a basic register script in Android Studio. Thanks in advance


Exporting QGIS Raster/Vector layers into one PDF?

I have seen a similiar post to this a while back (), and thought I would try asking it again to see if there has been any improvement or new knowledge on this.  Is it possible to export one PDF with multiple layers like the picture shows?    The above shows a Raster image (WMS) and 4 different Vector layers, is it possible to get all these into one PDF as different layers? As shown below, where you can click/unclick each layer?


why using strips in the url database Mysql php cannot be read

I have a problem calling the database in the URL with MYSQL, where I call the url post  /post/**how-to-noodle-with-egg**  why does the database call an error with a strip at the URL?  if me display in page use  $_GET['title'];   why only get "how"? why not get  full url? so page post me not found data because only get "how" not full text with strip  My code :  $a = $_GET['title'];  "SELECT * FROM `post` WHERE title = '$a";   in my database  title : how-to-noodle-with-egg ( use strip )  maybe someone here can help my problem


I would like to ask for a help. I've recently fell in love with analog photography. My grandfather gave me these cameras: Werra with Tessar (2,8/50) Lens and Praktica PL nova 1 with Oreston 1,8/50 lens. I tried to take photos with them but I found out that analog photography is an expensive business these days. So I wondered if it is possible to attach these lenses to my Canon EOS 450D camera. I found out that they are selling Tessar with canon special eos bayonette on ebay, but I would rather buy only the bayonette/adapter and mod it by myself.  Could anyone please tell me which types (or models) of adapters would suit for my Canon EOS / vintage lenses?


Hat does not display fully on a user's activity page

I'm aware Winter Bash is ending soon, but perhaps this could be fixed for next year's WB. As seen in the image below, my hat does not display fully.    It appears that this can be fixed by removing overflow: hidden from [class * ="gravatar-wrapper-"] in primary.css. [class * ="gravatar-wrapper-"] {     padding: 0;     overflow: hidden }


Word For When You've Been Forced to No Longer Trust Something or Someone

Often, I encounter situations (particularly with software or electronics, though occasionally with people) where bugs or strange events happen that cause me to lose trust in said software maintaining the integrity of my data, or said technology being reliable 'in the clutch' (or even scenarios where a person or business entity change a predictable, relied-on pattern of behavior, belief or expectation).   Sometimes I feel so strongly about the broken trust, that I feel forced to stop trusting (even if such events leading to the distrust were unintentional). I may still use said software, but I continue to do so very cautiously at that point.   The word I believe I'm looking for is similar to 'ized' words, in that it describes a state of 'forced distrust' assigned to myself, not the state or act of the object/person breaking the trust (e.g. "I've been/become xxxxxxxized by such-and-such...").   I often want to use the word 'disenfranchised' to describe such a state, but I'm not sure that's 100% suitable to the various contexts or the concept of lost trust (even though whatever trust I had was likely unfounded anyway, simply because, at least in the context of software, that trust is simply the lack of distrust due to having not yet experienced any bugs/issues that have built up a negative rapport with said software and what I expect it to do without fail).   So what's the word I'm looking for, if such a single word exists?


What is the physical meaning of commuting in quantum mechanics?

In quantum mechanics, if two observables commute, then perfect knowledge can be gained about both observables simultaneously. But what does the commutator actually, physically represent? Like observables correspond to things that can be observed, is there a similar physical meaning or classical analogy for commutators?


I've jus wrote simple Bash program: #!/bin/bash  function logMessage() { }  var1=initial  { true; var1=$?; }  { false; var1=$?; } | logMessage  echo var1 is: $var1  I expect var1 to be 1 (false) but it is 0 (true): ./test.sh  var1 is: 0  How to make second "var1=$?" working as expected while keeping pipe unchanged? Thank you in advance for any ideas!


I want to describe my business and want to refer to it in a sentence.  I am trying to say:      "In 2015 we established a business (that is) named X".   Intuitively, the "that is" part is redundant, and makes the sentence more cumbersome. But I cannot think of a reason why we should be able to drop the verb.  Is the version without the "that is" part grammatically correct? How can it be explained?


What do memory configurations like "256Kx18" mean?

This is a beginner question here. When choosing memory ICs, one of the options is the memory size/configurations. I understand the size part, but what does the "16Kx9" mean? It seems the same memory size is usually available in different configurations. I attached a screenshot from Digikey as an example.


Can you use 2 Minecraft mods simultaneously?

I was wondering if you could simultaneously load 2 mods such as a hacked client like Nodus, and TMI? I have tried to just place both jar files but that did not work.


How can I edit an image so it doesn't come up on google images search

I am building an online game that works with images. The user has to guess who's in the altered image that the website displays. So far so good just that if the user does a google search for the image he can find the answer within seconds.   How should I alter the image in order to get it off the google images search?  EDIT: The images I use are already available on google. eg: Barrack Obama. We use images of well known people in our game. That's why I wanted to edit them and avoid the google search


How much time does top command consider while finding CPU usage percentage?

Top gives me an output like:  %Cpu(s):  4.7 us,  1.3 sy,  0.0 ni, 93.9 id,  0.1 wa,  0.0 hi,  0.0 si,  0.0 st   if my CPU has spent 4.7% of its time on user processes, how much of time history has it considered before coming up with such a result?


Wikipedia lists the  as a hypothetical particle. I wonder whether graviton is indeed hypothetical or does its existence directly follow from modern physics? Does observation of gravitational waves amount to the discovery of graviton or could there be gravitational waves not composed of gravitons?


What is the iOS alternative to a radio button?

There is a radio button in android and WEB but what is the best alternative in iOS? And please don't say segmented control becuase it's not working in my case.   The case is a list of items 3-6 which have 1-3 words of text each and it is required to pick 1.


Using ogr2ogr to reproject and rename into shapefile?

I'm trying to reproject, move from tab to shp and rename all the .tab contained in a folder tree using ogr2ogr.  I'm working with Windows 7, QGIS 1.8 installed with advanced OsGeo4w and gdal 1.9.2. I have no experience in batch.  Here's the code :  for /R %%f IN ('D:\3.BATCH\FAUNE\*.tab') do C:\Users\Samy\Desktop\SIGMA\15.webmapping\ms4w\tools\gdal-ogr\ogr2ogr.exe -s_srs EPSG:3727 -t_srs EPSG:2975 %%f "ESRI Shapefile" %%f_2975.shp %%f pause   By calling this .bat into the cmd line, nothing append. When I simplify the code, I have in the best case "Unable to open" as Nik posted in the 3rd ressource below.  I wrote this code with the following questions:        According to resource 1, I translate the -f "MapInfo File" "%~dpnf.tab" "%f" into %%f "ESRI Shapefile" %%f_2975.shp %%f because as it is shape, I can't use dpnf.  According to resource 2, I wrote -s_srs EPSG:3727 -t_srs EPSG:2975 to reproject.  Finally I checked that the "Hide extensions for known file types" was off, according to ressource 3.  I don't know what to do now. There seems to be so many different ways to write this one line of code.


Qualification required to become a Software Tester

One of my friend wants to start career in Software Testing. I have suggested him to join some software testing classes and take ISTQB foundation level certification.   But the thing is he has qualification , 12th + diploma in IT and also he is doing some kind of network support work since 3 year in a non IT firm.  I'm not sure that above qualification accepted for Software Tester job role?  Suppose he has done certification and will have required skill then will it be comfortable to get a job after these many years of gap ?  Can someone please suggest ?


which usb antivirus is better for cleaning virus that hides files and also remove important.exe

i have a big problem. my USB-flash is infected by a virus that hides my files. every time i connect my USB-flash to my PC the files will be hide. there is another more virus. important.exe. i need a light and powerful antivirus that remove all USB related viruses and guarantee to keep my USB-flash protected.


How do I make a pickaxe that can break bedrock?

I'm fine if you just give me the NBT or something but I'm on an anarchy realm and need to give my friend a pick to break bedrock since he's on console and can't download exploits.


What's a concise way to check that environment variables are set in a Unix shell script?

I've got a few Unix shell scripts where I need to check that certain environment variables are set before I start doing stuff, so I do this sort of thing:  if [ -z "$STATE" ]; then     echo "Need to set STATE"     exit 1 fi    if [ -z "$DEST" ]; then     echo "Need to set DEST"     exit 1 fi   which is a lot of typing. Is there a more elegant idiom for checking that a set of environment variables is set?  EDIT: I should mention that these variables have no meaningful default value - the script should error out if any are unset.


Creating non-reverse-engineerable Java programs

Is there a way to deploy a Java program in a format that is not reverse-engineerable?   I know how to convert my application into an executable JAR file, but I want to make sure that the code cannot be reverse engineered, or at least, not easily.   Obfuscation of the source code doesn't count... it makes it harder to understand the code, but does not hide it.  A related question is     Once I've completed the program, I would still have access to the original source, so maintaining the application would not be the problem. If the application is distributed, I would not want any of the users to be able to decompile it. Obfuscation does not achieve this as the users would still be able to decompile it, and while they would have difficulty following the action flows, they would be able to see the code, and potentially take information out of it.  What I'm concerned about is if there is any information in the code relating to remote access. There is a host to which the application connects using a user-id and password provided by the user. Is there a way to hide the host's address from the user, if that address is located inside the source code?


ADDITIONAL INFORMATION  Again i am writing on the above issue (Preventing multiple instances of my application)  the code works for if i start two instances from programe menu/desktop shortcut. but in my envrironment,   one instance is running from Window Service.   another from Desktop shortcut with Same parameter.  Any help how to write the code ?


Where display normals is located in Blender 2.80?

I would like Blender 2.80 to display face normals in edit mode.  Where this option is located inside the GUI in Blender 2.8?


Can I use a higher rank tensor field as the metric field?

What a metric should necessarily do is it should give me a way to associate a frame invariant number with a given pair of spacetime events. Now, if I use a higher rank tensor field (say, for example, a tensor field of rank 3: $g_{\mu \nu \rho}$) then also I can certainly produce a frame invariant scalar out of a given displacement $\vec{A}$ in this trivial way: $ I := g_{\mu \nu \rho} A^{\mu}A^{\nu}A^{\rho}$. Since the components of the higher rank tensor and that of the displacement vector are going to transform in a covariant and a contravariant manner respectively, the cooked up quantity is certainly a scalar.   Another crucial property, which I think has more direct physical content than the previous one, is that between two inertial frames, at least one such transformation should exist that leaves at least one metric invariant. i.e., There should exist at least one combination of transformation matrix $\displaystyle\frac{\partial{x^{\alpha}}}{\partial{x^{\mu '}}}$ and metric $g_{\alpha \beta \gamma}$ that satisfies the following equation:      $\displaystyle\frac{\partial{x^{\alpha}}}{\partial{x^{\mu '}}}\displaystyle\frac{\partial{x^{\beta}}}{\partial{x^{\nu '}}}\displaystyle\frac{\partial{x^{\gamma}}}{\partial{x^{\rho '}}} g_{\alpha \beta \gamma} - \delta_{\mu '}^{\alpha}\delta_{\nu '}^{\beta}\delta_{\rho '}^{\gamma} g_{\alpha \beta \gamma} =0$    The last thing I can think of that can put a restriction on the choice of a tensor as a metric is the existence of a possibility of finding a metric compatible symmetric connection field. Following the usual procedure of finding the expression for a metric compatible symmetric connection field, I reached following condition (unlike the case of the usual two rank metric where we get a full-fledged expression) for the connection in the terms of the metric:      $g_{\nu \rho k_1} \Gamma^{k_1}_{\mu \lambda} - g_{\lambda \mu k_2} \Gamma^{k_2}_{\rho \nu} = \displaystyle\frac{1}{2} (\partial_{\nu}g_{\rho \lambda \mu} + \partial_{\rho}g_{\lambda \mu \nu}  - \partial_{\lambda}g_{\mu \nu \rho}  - \partial_{\mu}g_{\nu \rho \lambda}) $   My question is that if it is possible to satisfy the two highlighted conditions then can we use such a 3 rank (or even higher rank tensors with similarly produced conditions) tensor fields as metric fields?   PS: This is NOT a proposal for a new home-production theory of gravity (or that of anything for that matter) but rather it is just that I am trying to understand why a two rank tensor is used in General Relativity as the metric. Thank you.


We will join you in an hour.We will be joining you in an hour

We will join you in an hour. We will be joining you in an hour.  What difference in the meanings do you see in these sentences.  Is it correct?  We will join you=we have just decided.  We will be joining you=a previous arrangement.  I shared my views.  Let see. What do you explain about them?


I used Kingoroot to root my Micromax Canvas A116 yesterday. And Kingoroot installed its own superuser app as a rooting procedure.  The problem is kingoroot's superuser is paid and displays ads and auto install apps if you don't buy it. I tried downloading Supersu but it gives an error "SU binaries occupied". How can I change superuser permissions from Kingoroot to Supersu?  Thanks.


Top cohomology and irreducible components

Consider a connected (possibily reducible) proper algebraic variety $X$ over $\mathbb{C}$ of pure dimension $n$. Is it true that $H^{2n}(X,\mathbb{Q})\cong \mathbb{Q}^r$ with $r=$#irreducible components of $X$, where the left-hand side is the singular cohomology with respect to the analytic topology?


translation invariant of integral on $\mathbb{R}$

Problem 1: Let $f\in L^1(\mathbb{R})$, show $\int_\mathbb{R}f(t)dt=\int_{\mathbb{R}}f(x+t)dt,\forall x\in (-\infty, \infty)$.  Problem 2: Let $f\in L^1(\mathbb{R})$,show $\displaystyle \lim_{t\rightarrow 0}\int_{\mathbb{R}}|f(x+t)-f(x)|dx=0$.  My try for Problem 1:  Consider $\displaystyle \int_{\mathbb{R}}f(t)dt=\lim_{n\rightarrow \infty}\int_{-n}^nf(t)dt=\lim_{n\rightarrow \infty}\int_{\mathbb{R}}f_n(t)dt$, where $f_n(t)=f(t)\chi_{[-n,n]}$.  And since $dt=d(x+t)$, we have $\displaystyle \int_{-n}^nf(x+t)dt=\int_{-n+x}^{n+x}f(t)dt$.  So for each $x\in (-\infty,\infty)$,  $$ \begin{split} \int_{\mathbb{R}}f(t)-f(t+x)dt &=\lim_{n\rightarrow \infty}\int_{\mathbb{R}}f(t)(\chi_{[-n,n]}-\chi_{[-n+x,n+x]})dt\\ &=\lim_{n\rightarrow \infty}\int_{\mathbb{R}}f(t)(\chi_{[-n,-n+x]}-\chi_{[n,n+x]})dt\\ &=\lim_{n\rightarrow \infty}\lim_{k\rightarrow \infty}\int_\mathbb{R}\varphi_k(t)(\chi_{[-n,-n+x]}-\chi_{[n,n+x]})dt\\ &=\lim_{k\rightarrow \infty}\lim_{n\rightarrow \infty}\int_\mathbb{R}\varphi_k(t)(\chi_{[-n,-n+x]}-\chi_{[n,n+x]})dt \end{split} $$ where $\varphi_k(t)$ is simple function pointwise converges to $f(t)$, simple function vanish out of set of finite measure, so $\varphi_k(t)(\chi_{[-n,-n+x]}-\chi_{[n,n+x]})$ vanishes when $n$ big enough(is this right?)    Another try:  Since $f\in L^1$, $f$ is bounder a.e. so can be approximated by simple functions, and $\chi_{A+t}(x)=\chi_A(x-t)$,thus $$\int f(t)=\lim_n\int\varphi_n=\lim_n \sum_{i=1}^nc_i\mu(E_i)=\lim_n \sum_{i=1}^nc_i\mu(E_i-x)=\int f(t+x)$$  For problem 2, I guess they share the same method.   Any help or correction about these two problems? Thanks.


A Commutative Ring Having a Unique Prime Ideal (Dummit and Foote, Prob 7.4.40(i))

I am trying to solve Problem 7.4.40 from Dummit and Foote, a part of which states:          Let $R$ be a commutative ring with $1\neq 0$ such that $R$ has exactly one prime ideal.     Then every element of $R$ is either nilpotent or a unit.      ATTEMPT: Let $P$ be the unique prime ideal of $R$. We will show that every element of $R\setminus P$ is a unit. Let $r\in R\setminus P$. Then the ideal $(r)$ is either equal to $R$ or is a proper ideal of $R$. If $(r)=R$ then $r$ is a unit. So assume $(r)\subsetneq R$. But then $(r)$ is contained in a maximal ideal $M$ of $R$. Clearly $M\neq P$. But $M$ is also a prime ideal of $R$ since it is a maximal ideal of $R$, giving a contradiction.  So we have shown that $x\in R\setminus P\Rightarrow r$ is a unit.  Also, since $P$ is prime, we have $\mathfrak N(R)\subseteq P$.  What I am struggling with is showing that $\mathfrak N(R)=P$.    NOTE: The result that $\mathfrak N(R)$ is the intersection of all the prime ideal of $R$, where $R$ is a commutative ring with $1\neq 0$, is not yet discussed in the textbook (See the comment in Problem 7.4.26 in D&F). So I think there must be an elementary argument which shows $\mathfrak N(R)=P$ in the question at hand.  Thanks.


Upgrade iPhone 5 from iOS 7.0.4 to iOS 7.1.2

I have an iPhone 5 that I use with Straight Talk (telecom provider) and I am trying to "upgrade" it from 7.0.4 to 7.1.2, or any release with the 7.x version for that matter.  I specifically do not want to upgrade to IOS 8 just yet.   I have the file "iPhone5,2_7.1.2_11D257_Restore.ipsw" but I get the error "The device isn't eligible for the requested build." I've also hashed out the gs.apple address in my hosts file.  I know you can't downgrade from 8 to 7, but in this case is there a way I can still upgrade to a later version of 7.x?


currently I'm actually having a security concern regarding acquiring root privilege on my server.   Current situation: I login using SSH to my server and I use my user account for this, this user account can also get root privilege with the same password.   Required situation: Login with the user, require a DIFFERENT password for root privilege.