Isekai manga where the main protagonist has a pet giant slime and also befriends a suit of armor with a spirit by beating them

I recall one moment from the manga where the main protagonist with his companions defeated some bandits, and then proceeded to pose as said bandits to a hero's party to train them(?).  This is basically the standout moment from it I can remember.


Can you really have a function/method without a body but just a try/catch block?

Note that this function does not have a "{" and "}" body.  Just a try/catch block:  void func( void ) try {     ... } catch(...) {     ... }   Is this intentionally part of C++, or is this a g++ extension?  Is there any purpose to this other than bypass 1 level of {}?  I'd never heard of this until I ran into


I am extremely interested in GR, but somehow feel that the books I read are not really enough. Frankly, I find many question on this site and elsewhere completely bewildering, which makes me think that I don't have a solid foundation, especially in classical mechanics and various mathematical techniques. Here's a list of books I have read:  MATHEMATICS(After pre calculus and basic calculus)  Mathematical methods for physicists(Still working my way through) By Arfken and Weber  Advanced calculus by David Widder  Ordinary differential equations by Coddington  Principles of mathematical analysis by Rudin  Vector Calculus  Tensor calculus by Barry Spain  RELATIVITY  Introduction to special relativity by Resnick  Gravity by Hartle  General relativity with applications to astrophysics by Straumann (newly acquired)  I have a few books on dynamics, nuclear physics, etc, but they are quite unnecessary. I am not much into QM, and have only read Griffith's. I also have, as a reference, PRINCIPLES OF PHYSICS by Resnick and Walker.  All my knowledge of classical mechanics and lagrangian formulism is from pdf versions of Feynman's lectures. Please suggest me some books that will fill the gap I have left out. Just to be clear, I want to read Mathematical theory of black holes by Chandrahekhar next, so I want to know where I need to improve.   NOTE: I am still in high school, and I don't have any professor to help me out, so the books should be suitable for self study. All the same, they should be properly rigorous.  EDIT: I am not very comfortable with the exercises suggested in most of the books (esp. Mathematical methods for physicists and both the GR books. Though I have no conceptual glitches, I really want to be able to solve the exercise problems, as doing so is both satisfactory and rewarding. Any suggestions on that( how to be more efficient)? Am I going too far too soon, and maybe need to stop down and consult a book which will perhaps give me a good foundation to solve the exercises, or a book with excellent exercises? If so, which one? 2: Of course, I have viewed the lectures by Susskind.


Let X be a topological space. Show that X is $ T_2 $ if, and only if, $ \alpha $ = {(x, x) $ \in $ X $\times$ X : x $ \in $ X} is closed at ...

Let X be a topological space. Show that X is $ T_2 $ if, and only if, $ \alpha $ = {(x, x) $ \in $  X $\times$ X : x $ \in $ X} is closed at  X $\times$ X. =================================================================== By Hausdorff definition we have x, y $ \in $ X, with x $ \neq $ y, there are U, V $ \subset $ X open such that x $ \in $ U, y $ \in $ V e U $ \cap $ V = $ \emptyset $. Assuming that close in X $ \times $ X = A and that to be close $ A^c $ needs to be open. But if X is Hausdorff that means that exist x $\in$ X, U $\subset$ X open, where x $\in$ U. But that doesn't mean X $\times$ X is open?


Beveling along a straight path — why does size change?

I'm trying to sweep a profile curve along a path curve, where the path curve (the one to which I'll apply the bevel) is a simple set of straight lines and right angles.  When I set the path curve's Bevel Object to the profile curve, I get roughly the desired result, except that the size of the profile curve gets bigger as it approaches the ends of the path. Why is that, and what do I do about it? (I tried setting a straight taper curve, but that doesn't help.)  Here's a simple blend file showing the problem:      Thanks!


I once came across a word in English that is used to describe the following situation:  When a word in one language means something rude when pronounced the same way in another language. An example could be "kiss" in English which means "Pee" in Swedish.  I've desperately tried to find out what that word is but with no luck.  Can anyone help?


Show Dialog Window if User logout on High Sierra

When a user logout, I want to display a window. In this window should be a text (Please save your data...). After the user has pressed OK. The process logout continue. Is this possible?   onLogout() (     # that works:     if [ "$USER" != "admin" ] && [ "$USER" != "Administrator" ]; then         rm -Rf ~/Downloads/*         rm -Rf ~/Movies/*         rm -Rf ~/Music/*         rm -Rf ~/Pictures/*         rm -Rf ~/Public/*         rm -Rf ~/Desktop/*     fi     # it doesn`t work:     res=$(osascript -e 'tell app "System Events" to display dialog "Please save yout Data!" buttons {"Cancel", "OK"} default button 1 with icon caution with title "Important Information!"' 2>/dev/null)          if [[ $res == *OK* ]]; then              # continue logout?         else             # break logout?         fi     exit ) trap 'onLogout' SIGINT SIGHUP SIGTERM while true; do     sleep 86400 &     wait $! done


Is this vector-valued map Hölder-continuous?

Pick $0<q<1$ and consider the map from $\mathbb{R}^n$ to $\mathbb{R}^n$ that sends $x$ to $|x|^{q-1}x$. Is this map Hölder-continuous (I guess with exponent $\leq q$)? In dimension one, I can exploit the homogeneity of the inequality defined by Hölder-continuity; but how can I proceed in higher dimension?


Illustrator: How to scale precisely to a specific (off-screen) reference point?

In Illustrator is there a way to precisely scale to a pivot point or "reference point" that is off the screen? I mean when you want to zoom in somewhere far away from where you set that point and then scale precisely to align something.   Here's :     To scale relative to a different reference point , click where you   want the reference point to be in the document window, move the   pointer away from the reference point, and then drag until the object   is the desired size.   Well, I tried using this click-drag scaling method as well, but the level of precision is too low to be usable. It overshoots or undershoots the guide I'm aiming for.  The Scale tool's pop-up dialog isn't useful either. It only offers percentages. And moving/zooming are disabled while the dialog window is up, meaning I cannot navigate to the guide I need to see.  For these reasons, I need to be zoomed in on the guide, tweaking the measurements from the top Control Panel.  Some images to help illustrate what I mean:    ▲ The circle marks where I would like the center of my scale transformation to be.    ▲ Now zoomed in somewhere else, I am trying to get the black border of this bitmap image to align perfectly with the vector guide by scaling it.    ▲ I nudge the numbers in the Control Panel until the image is perfectly aligned.  One would think all would be perfect, but then I look and my reference point has vanished!   It seems the scaling has been executed relative to one of these limited nine reference point choices  instead of the reference point I specified.  There must be a way to scale precisely to a specific reference point in illustrator. Can somebody please enlighten me?


How do I make log4j clear a log at startup?

I want the log to roll over as long as the application is running, but I want the log to start fresh when the application is restarted.  Updated: Based on  feedback, my appender looks like this:     <appender name="myRFA" class="org.apache.log4j.RollingFileAppender">       <param name="File" value="my-server.log"/>       <param name="Append" value="false" />       <param name="MaxFileSize" value="10MB"/>       <param name="MaxBackupIndex" value="10"/>       <layout class="org.apache.log4j.PatternLayout">          <param name="ConversionPattern"             value="%d{ISO8601} %p - %t - %c - %m%n"/>       </layout>    </appender>   I simply added the following line:  <param name="Append" value="false" />   It now truncates the base log file at startup, but it leaves the rolled files alone.


Solve the equation $((x+y i)-\frac{1}{x+y i})/{(2 i)} = 2$

Solve the equation $$\frac{\left((x+y i)-\frac{1}{x+y i}\right)}{2 i} = 2$$   So far, I got $(0, 2-\sqrt{3}i)$ and $(0, 2+ \sqrt{3}i)$ as solutions for $x$ and $y$. Do I require $2$ more solutions?


cannot understand sql injection explanations

Could somebody correct this statement to stop sql injection, I have read through lots of answers but don't understand how to do it.   $conn = new mysqli($servername, $username, $password,   $dbname);  if ($conn->connect_error) {  die("Connection failed: " . $conn->connect_error);  }    $sql = "UPDATE daydxx SET $T1 ='$Dsc', $T2 = '$SV'  WHERE date = '$Dt' AND   $T1 = '' OR date = '$Dt' AND $T1 IS NULL ";   if ($conn->query($sql) === TRUE) {  etc etc


Flight BA677 31 july 2016 Istanbul - London

I need to find arrival time in London Heathrow of the BA 677 flight on 31 july 2016. Can somebody help me? i tried flightstats and other websites but historical flight status check is not free. Thank you,  Takoz


Should feature normalization be done for training , test set and target variables together?

Consider a matrix X where the columns are the attributes and each row is an example. There is no order of occurrence of the examples. The target variables are continuous valued.  Does normalization to 0 mean and 1 standard deviation occur by considering the mean and standard deviation each column separately or for each row? Do we have a mean and sigma for each column? My confusion is that each feature is in a row representing and example. So feature normalization should be done for each example. But I may be wrong.  QUESTION 1) Should each row be normalized or each column wise? Is this the correct approach for calculating the mean and standard deviation for normalization (in MATLAB) and then apply it for normalization to zero mean and 1 std? I am calculating the mean and sigma for each attribute across all examples.  %X = data matrix rows are the number of examples, columns are the attributEs for i = 1:size(X, 2),   mu(i) = mean(X(:,i));   sigma(i) = std(X(:,i)); end   Example:   X= [1 2 4; 1 1 1; 3 2 2; 0 0 0]; %4 examples and 3 attributes  %for each column there is a mu and sigma mu =      1.2500    1.2500    1.7500 sigma =      1.2583    0.9574    1.7078   QUESTION 2) My dataset is composed of the input and targets (continuous valued). Should normalization of the entire dataset which contains the input and target be done altogether and then should the splitting of the normalized dataset into train, validation and test set and traintarget and test target be done?    Please correct me where wrong.


Earth Engine convert list with coordinates and values into a feature collection for export

I need to create a feature collection from a list containing coordinates and band values.  These are extracted from a landsat image as shown in this linked script.    I'm unable to find a solution in creating a feature collection.  Here is the tail end code.  var valuesList = joinedImage.reduceRegion({   reducer: ee.Reducer.toList(4),   geometry: myGeometry }).values().get(0);  var feature = ee.Feature(null, valuesList);   // Wrap the Feature in a FeatureCollection for export. var myFeatures = ee.FeatureCollection([feature]);   // Export the image, specifying scale and region. Export.table.toDrive(myFeatures, "data", "myData", "B4-B5",  "CSV");   This doesn't work, because it is clearly the wrong way to create the feature collection.  I've tried to create it similar to Rodrigo E. Principe's solution of mapping a Feature Collection but I can't seem to create the initial feature collection to start with.


Why does Joule's Law of Heating defined by $H=i^2R$ only?

Joule's Law Of Heating states that for a conductor Heat loss is given by $$H=i^2Rt$$ Couldn't we substitute $$V=iR$$ and show that $H=(V^2/R)t$ ?  If this is so, when transmitting power across large distances, we should keep voltage low which seems to contradict reality. Where am I going wrong?


We have a pool of N number of balls.  There are: A number of white balls (W), B number of green balls (G), C number of blue balls (B), and D number of pink balls (P)  In how many ways (combinations) we can pick X number of balls from this pool? Is there a formula for something like this?  This is similar to combinations with replacement, but there are limitations to how many times a certain object can be replaced.


I'am looking for social network datasets for determining the strength of (acquaintance, friendship, family ,professional,...) relationships can any one help me to find it  thanks in advance


By using the fact that $\log(n)<<n$，evaluate $\lim n^{1/n}$.

By using the fact that $\log(n)<<n$，evaluate $$\lim_{n\to \infty} n^{1/n}$$  How to use $\log(n)<<n$ to evaluate that?


How to make footcite refer to the first footnote when citing identical references?

I am writing a document where I am forced to insert citations of relevant bibliography as footnotes. I am using a similar text for comparison, and I noticed that the bibliography style is rather compact:  As it is shown in [1], $2=1$; compare also [2] for a more combinatorial proof of this result.   [...]   Remember that the main theorem in [1,2] entail that $2=1$; [3]  aims to apply this result to a statement equivalent to RH (see [4]).  ========= [1]: N. True; "A simple proof of something false" (1989).  [2]: A. Las; "A difficult proof of something false" (2001). [3]: T. Kyle; "You could have proved something better than this" (2002).   When referring again to [1], only a superscript with the corresponding footnote where it has been cited the first time is printed. I think this is done with clever cross-referencing and a bit of biblatex magic, but my bib-fu is rather poor, so I'm not able to backward-engineer the pdf to understand how this is done.   I tried by simply juggling with styles in biblatex options, to no avail.    Edit: I produced a MWE:  \documentclass{article}  \usepackage{filecontents,lipsum} \usepackage[style=verbose-ibid,backend=bibtex]{biblatex}  \begin{filecontents}{\jobname.bib} @article{ntrue,   title={A simple proof of something false},   author={N. True},   journal={Journal of Pure and Applied Algebra},   volume={9},   number={2},   pages={207--220} }  @article{alas,     AUTHOR = {A. Las},      TITLE = {A difficult proof of something false},    JOURNAL = {J. Homotopy Relat. Struct.},     VOLUME = {2},       YEAR = {2007},     NUMBER = {2},      PAGES = {295--314},    MRCLASS = {18E40 (18D30)},   MRNUMBER = {2369170 (2008m:18023)} }  @article{tkyle,     AUTHOR = {T. Kyle},      TITLE = {You could have proved something better than this},    JOURNAL = {Trans. Amer. Math. Soc.},   FJOURNAL = {Transactions of the American Mathematical Society},     VOLUME = {353},       YEAR = {2001} } \end{filecontents} \addbibresource{\jobname.bib} \begin{document} As it is shown in [\footcite{ntrue}], $$2=1.$$ compare also [\footcite{alas}] for a more combinatorial proof of this result.   \lipsum[3]  Remember that the main theorem in [\footcite{ntrue}, \footcite{alas}] entail that $2=1$; [\footcite{tkyle}] aims to apply this result to a statement equivalent to RH. \end{document}   I want that the second reference \footcite{ntrue} points to footnote 1. Obviously (if possible) without defining a command which refers to a footnote (this forces me to keep track of each occurrence of each key, and note manually who's the first: it can be done, but...)


Inaccurate coefficient output when using binomial glm in R

I have a data set that has 8 treatments, along with success data. I used a binomial glm to analyze the data, but generated some unexpected coefficient values for a few of the treatments and not sure what to do about it.  Here is the data and summary:  treatment = as.factor(c("A", "A", "A", "A", "B", "B", "B", "B", "C", "C", "C", "C",  "D", "D", "D", "D", "E", "E", "E", "E", "F", "F", "F", "F", "G",  "G", "G", "G", "H", "H", "H", "H")) rep = c(1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4,  1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4) success = c(1, 1, 1, 2, 14, 17, 15, 18, 0, 0, 0, 0, 18, 18, 17, 18, 4,  4, 2, 4, 2, 4, 1, 1, 1, 0, 0, 1, 8, 6, 6, 2) total = c(20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,  20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20, 20,  20)  data = data.frame(treatment,rep,success,total) data$perc = data$success/data$total  library(tidyverse) data %>% group_by(treatment) %>% summarize(mean = mean(perc))   We can see that the mean for treatments B and D are .8 and .88 respectively.  Now perform a glm:  model.glm = glm(cbind(success,total) ~ treatment-1,data = data,family="binomial")  logit2prob <- function(logit){   odds <- exp(logit)   prob <- odds / (1 + odds)   return(prob) }  SuccessProb = logit2prob(coef(model.glm)) SuccessProb = round(logit2prob(coef(model.glm)),2) SuccessProb   We can see that the estimates, using a glm, for B and D are .44 and .47, respectively. These are not close to the summary estimates.  If we use an anova, results are better.   model.aov = aov(perc ~ treatment-1,data=data) SuccessProb.aov = coef(model.aov) SuccessProb.aov   Here, the estimates for B and D are .8 and .89. Much better than the glm.  Does anyone know what I am doing wrong here?


$V = V_1 + V_2$ confusion? Why is my "proof "incorrect?

Why isn't $V= V_1 + V_2$? $V=V_a - V_c = V_a - V_b + V_b - V_c$, $V_a - V_b= V_1$ and $V_b - V_c = V_2$ Doesn't that prove that $V = V_1 + V_2$? Regardless of $V_3$, If i'm wrong , is there a way to obtain $V$ in terms of $V_1$, $V_2$ and $V_3$


How to typeset stacked, unrelated equations?

I fail to find a way to typeset a stack of unrelated equations. As an example, I would like to have these two unrelated equations one under the other: ax+by+c=0 and E=mc^2. I could go for \begin{align}...\end{align} but there is no particular reason to align them against something. I tried to break them via \\ in a \begin{equation}...\end{equation} environment but this is not taken into account (the equations are concatenated in one line). I tried \begin{multiline}...\end{multiline} and \\ but it breaks the equations and justify them one to the left and one to the right. I finally broke them into two \begin{equation}...\end{equation} but they are too much spaced vertically. Is there a simple "multiline left justified" environment I could use? As a workaround, if there are no straightforward solutions I will probably go for align.


Amending PATH so that /usr/local/bin is ahead of /usr/bin

I'm trying to install brew but get the following warning:  Warning: /usr/bin occurs before /usr/local/bin This means that system-provided programs will be used instead of those provided by Homebrew. The following tools exist at both paths:  2to3 2to3-2.7 idle idle2.7 pydoc pydoc2.7 python python-config python2.7 python2.7-config pythonw pythonw2.7 smtpd.py smtpd2.7.py  Consider amending your PATH so that /usr/local/bin is ahead of /usr/bin in your PATH.   I have no idea how to amend the path.  I've explored several files from this stack overflow post (http://stackoverflow.com/questions/8886114/using-brew-with-ruby-1-9-2), but can't find a relevan path to edit.  The only file that I do have that exists is my /etc/profile file which currently looks like:  # Setting PATH for Python 2.7 # The orginal version is saved in .bash_profile.pysave     PATH="/Library/Frameworks/Python.framework/Versions/2.7/local/bin:${PATH}" export PATH   I wanted to just uninstall python then reinstall it through homebrew, but am a little nervous about breaking too many things at once.  Is there an easy way to amend the path?  Should I create a .bash_profile file?  Thank you for any help in advance.


How can I get System variable value in Java?

How can I get the System Variable value which is present in   MyComputer -> Properties -> Advanced -> Environment Variables -> System Variables   in Java?  Edit  I have used System.getenv() method.  It is printing value if I give   System.out.println(System.getenv("JAVA_HOME"));   and it is showing null value if I try the same for system variable created by me   System.out.println(System.getenv("DBE"));


Is the one-dimensional Lie algebra L=C semisimple?

I might be wrong, but I think it is not simple since $[x,x]=0$ and thus abelian which means it cant be simple? Any clarification would be appreciated!


Staggering the authentication delay on failed `su` or `sudo`

I'm about to start my new job as a sysadmin and I've been thinking about implementing a cooldown feature on su or sudo. The cooldown prevents the user from using these commands for a few seconds after the first failed attempt, and the waiting time increases with each failed attempt by some factor.  The idea behind the concept is that the authorized user might get it wrong the first time but will get it right on the second. The cooldown will be there to discourage and delay an adversary from using brute-force variations.  Is there a flaw in my approach? Would replacing the sudo command with a modified script be wise? Or should I patch the executable itself?    Edit: I've already searched for this on Google, nothing found. Same goes for SO, SuperUser.SE and Security.SE. If you feel this question isn't a fit for ServerFault, please flag it so.


Series read back in late 1900s: aliens with two life stages, one electronic

I read a series of books where the aliens had two life stages. One stage was like us, physical. When they died they became some form of electromagnetic existence, or something like that. This second stage is how they communicate over very long distances. Because of this, their entire culture used only ceramic and plastics. A long war with us broke out by accident because on first contact we tried to transmit a message electronically. This resulted in killing their second stage fellow, which was interpreted as aggression, and we've been at war ever since. Also by accident one of their second stage fellow became trapped in one of our research facilities.   Over the years he comes to realize the truth of the accidental start to the war and decides to eventually show himself, which eventually results in the end of the war. The other books in the series covers their culture and our growing mutual economies, and political intrigues.


Giving an example of a space with some homology groups

Give a space $X$ such that $H_i(X;\mathbb{Z}/3) \cong 0$ for all $i > 0$, but such that there is an $i > 0$ for which $H_i(X; \mathbb{Z})$ is non-trivial.   We know that the chain complex of $C_i(X; \mathbb{Z}/3) \cong C_i(X; \mathbb{Z}) \otimes \mathbb{Z}/3$. I think the best approach is to first find a chain complex satisfying this, using as many $\mathbb{Z}$-linearizations of sets as possible so we can use a CW-complex and cellular homology to realize the chain complex.  I have done nothing useful, but as posts should show some sort of effort, this is one of my failed attempts:  Consider the chain complex   $$... \to 0 \to 0 \to \mathbb{Z} \xrightarrow{1 \mapsto 6}  \mathbb{Z} \xrightarrow{1 \mapsto 1} \mathbb{Z}/3$$  This has $H_1(C)$ is non-trivial since $3$ is in the kernel, but not in the image.  Tensoring with $\mathbb{Z}/3$ gives  $$... \to 0 \to 0 \to \mathbb{Z}/3 \xrightarrow{0} \mathbb{Z}/3 \xrightarrow{a \mapsto 1 \otimes a} \mathbb{Z}/3 \otimes \mathbb{Z}/3$$  using the isomorphism $\mathbb{Z} \otimes A \to A: 1 \otimes a \mapsto a$.  Fails because $H_2(C \otimes \mathbb{Z}/3) \cong \mathbb{Z}/3$.


My Grandchildren say "May you pass the salt" etc. They say their teachers say this is ok. To me it sounds very clumsy and I had never heard it used except by them. They have grown in Wiltshire while we are south Hampshire. Is it regional?


How can Planck units be consistent with conflicting dimensions of mass?

I suspect I'm missing something obvious, but I'm coming up blank. I've gotten pretty comfortable with so-called natural units over the years: in doing quantum mechanics/QFT, it's common to set $c = \hbar = 1$ and in GR, it's common to set $c = G = 1$. I'm told that quantum gravity researchers are fond of , where (according to that Wiki page) we set $c = \hbar = G = 1$, along with a couple other fundamental constants. I don't know what to make of this, though: it's dimensionally inconsistent in 3+1 dimensions. That same article gives the dimensions of each constant:  $$\begin{align} [c] &= L T^{-1} \\ [G] &= L^3 M^{−1} T^{−2} \\ [\hbar] &= L^2 M T^{−1} \end{align}$$  Setting $c$ and $G$ to 1 implies $L=T=M$. Setting $c$ and $\hbar$ to 1 implies $L=T=M^{-1}$. Hence, making all three unity is internally inconsistent: mass cannot simultaneously have dimensions of length and reciprocal length. So, how do Planck units work?


I have a linode and I access via ssh throw terminal. I need to create an sftp user which his default directory (and the only he can access) is /var/www/xxxxxx.com/public_html/directory  Now, I did it, but when I try to connect I get broken pipe or connection rejected by peer  What I did is this:  $ adduser --home /var/www/xxxxxx.com/public_html/directory/ username $ chown username:username /var/www/xxxxxx.com/public_html/directory/ $ chmod 755 /var/www/xxxxxx.com/public_html/directory/ $ nano /etc/ssh/sshd_config   In /etc/ssh/sshd_config I added the following lines  Match User username    ChrootDirectory /var/www/xxxxxx.com/public_html/directory/    AllowTCPForwarding no    X11Forwarding no    ForceCommand internal-sftp   What am I doing wrong?  EDIT: This is the actual error    EDIT2: this is the error in filezilla    EDIT 3: auth.log   Oct 15 17:47:11 (none) sshd[361]: fatal: bad ownership or modes for chroot directory "/var/www/xxxxxxxxxxxx.com/public_html/extras_html"


How to display random jokes from www.icndb.com in your terminal?

I already know that you can get some nice quotes/jokes using the  program.  But I've found in this  a new source of fun that I'd like to have when I open a new terminal.  This time the jokes come from .


As all of us know, in c++ there are 3 ways of sending a value to a function:   by value like this:  void Example(int); by reference like this :  void Example(int&); by const reference:  void Example(const int&);   In first method, a copy of value will be used in function and so the value just can be read cant be wrote. In second method, parameter can be read and wrote , and in third, parameter will be used directly without any copy but cant be wrote. as third method occupy less memory (without taking any copy of parameter) why we usually use first method?  what is differences between them. Thanks.


Show that $n^3-n$ is divisible by $6$ using induction

As homework, I have to prove that     $\forall n \in \mathbb{N}: n^3-n$ is divisible by 6   I used induction  1) basis: $A(0): 0^3-0 = 6x$ , $x \in \mathbb{N}_0$ // the 6x states that the result is a multiple of 6, right?  2) requirement: $A(n):n^3-n=6x$  3) statement: $A(n+1): (n+1)^3-(n+1)=6x$  4) step: $n^3-n+(n+1)^3-n=6x+(n+1)^3-n$  So when I resolve that I do get the equation: $n^3-n=6x$ so the statement is true for $\forall n \in \mathbb{N}$  Did I do something wrong or is it that simple?


(Java Minecraft 1.14) How to detect when a spash potion explodes, and it's position when it explodes?

I'd like to summon a fuse 0 creeper at the position of a splash potion when the splash potion hits something. What I need to know is how to detect when it hits something. I have three ideas currently:  One idea was to give the potion a tag and store the Pos[] of the potion in scoreboards every tick after it was thrown, then test for if an entity with the tag exists, and when it stops existing (as it has hit something) summon the creeper at the last known coordinates. This has the detriment of only working for one potion at a time, and is likely very resource intensive.  Another idea is to execute as a thrown potion with any type of block right next to it, but I'd like to have it not trigger if I've thrown it through a plant or door or something. I was thinking of using a bunch of unless block ~ ~ ~ minecraft:___ with air, water, lava, and a bunch of plants, but the potion would break before it got in a block that wasn't one of the above mentioned ones so it would be very glitchy or not work at all.  Finally, I was considering trying to execute at the particles/effect caused by the potion (Instant Damage 4), but I have absolutely no idea how to do this, because I don't want to use lingering potions and there is no area effect cloud to execute at.  If anyone knows how to make one of these options viable or has a different suggestion, no matter how big or small, please put it down because I've spent several frustrating hours thinking of how to do this, and have not had much progress.


How do you force a 5 GHz wifi connection?

Wifi networks are often set up in dual-band mode, with the same SSID served on both 2.4 GHz and 5 GHz bands. I'd like to always use the 5 GHz band (due to interference with Bluetooth and other devices that degrades performance). How do I force Mac OS X to use the 5 GHz base station? (I do not have admin access to the network, so I can't just assign the 5 GHz network a different SSID.)  Note that this question is not asking how to force a particular flavor of 802.11, rather it is asking how to force a particular frequency band.


Regex working on regex101 but not in Python

The following is the text I'm using in the regex. I want to grab everything between ##Player Stats and ##Goalie Stats  [](#startinjuredreserve)  ##Injured Reserve |Position|Player|Salary| |:-|:-|:-| |RD|Oscar Fantenberg|$850,000| |LW|Antoine Roussel|$3,000,000|   [](#endinjuredreserve)  [](#startmagicalbotarea)   ##Schedule |Date|Time|Opponent|TV/Score| |::|::|::|::| |15 Oct|19:00|vs [Detroit Red Wings](/r/detroitredwings "Detroit Red Wings")|**W 5-1**| |17 Oct|17:00|@ [St. Louis Blues](/r/stlouisblues "St. Louis Blues")|**W 4-3**| |19 Oct|10:00|@ [New Jersey Devils](/r/devils "New Jersey Devils")|L 1-0| |**Today**|10:00|@ [New York Rangers](/r/rangers "New York Rangers")|**W 3-2**| |22 Oct|16:30|@ [Detroit Red Wings](/r/detroitredwings "Detroit Red Wings")|SN360| |25 Oct|19:00|vs [Washington Capitals](/r/caps "Washington Capitals")|SN1| |28 Oct|19:00|vs [Florida Panthers](/r/floridapanthers "Florida Panthers")|SNP|  ##Pacific Standings |Team|GP|W|L|OTL|PTS|Streak |::|::|::|::|::|::|::| |[Edmonton Oilers](/r/edmontonoilers "Edmonton Oilers")|8|7|1|0|14|W2| |[Anaheim Ducks](/r/anaheimducks "Anaheim Ducks")|8|6|2|0|12|W2| |[Vegas Golden Knights](/r/goldenknights "Vegas Golden Knights")|9|6|3|0|12|W2| |[Vancouver Canucks](/r/canucks "Vancouver Canucks")|8|5|3|0|10|W1| |[Arizona Coyotes](/r/coyotes "Arizona Coyotes")|7|4|2|1|9|W3| |[Calgary Flames](/r/calgaryflames "Calgary Flames")|9|4|4|1|9|L1| |[San Jose Sharks](/r/sanjosesharks "San Jose Sharks")|8|3|5|0|6|L1| |[Los Angeles Kings](/r/losangeleskings "Los Angeles Kings")|8|3|5|0|6|W1|  ##Player Stats Player|GP|G|A|P|+/-|PIM| |:|::|::|::|::|::|::| |Miller|8|4|4|**8**|5|4| |Pettersson|8|2|6|**8**|4|0| |Boeser|8|2|5|**7**|4|0| |Edler|8|3|3|**6**|-1|10| |Sutter|8|2|3|**5**|1|7| |Pearson|8|2|2|**4**|-4|2| |Tanev|8|1|3|**4**|1|0| |Hughes|8|1|3|**4**|1|2| |Horvat|8|2|1|**3**|0|2| |Leivo|8|1|2|**3**|1|2|  ##Goalie Stats |Goalie|GP|W|L|SV%|GAA|SO| |:|::|::|::|::|::|::| |Markstrom|5|3|2|0.932|2.19|0| |Demko|3|2|1|0.943|1.64|0|  ***** Updated at: 20 Oct 2019, 03:12 PM PST *****  [](#endmagicalbotarea)  ##Filter Options - If you want to block a certain type of posts, click one of the link filters below  - [No Shitpost/Memes](https://nm.reddit.com/r/canucks/#nm)  - [No Fan Content](https://nf.reddit.com/r/canucks/#nf)  - [No Memes or Fan Content](https://mf.reddit.com/r/canucks/#mf)  - [Reset Filter](https://reddit.com/r/canucks/)  ## Links & Resources  - /r/hockey - /r/UticaComets - /r/TheAthleticVAN  - [Canucks Capfriendly](https://www.capfriendly.com/teams/canucks) - [Canucks.com](https://www.nhl.com/canucks) - [Canucks Official Twitter](https://twitter.com/canucks) - [Canucks Official YT Channel](http://www.youtube.com/user/Canucks) - [Sportsnet 650 Vancouver](http://www.sportsnet.ca/650/) - [TSN 1040](http://www.tsn.ca/radio/vancouver-1040-i-1410) - [**Join /r/Canucks Discord!**] (https://discord.gg/UTZ5Vrb)  ## Subreddit Wiki  - [Rules and Guidelines](/r/canucks/wiki/rules) - [Streaming Guide](/r/canucks/wiki/streaming) - [Attending a Canucks Game?](/r/canucks/comments/2u5lxr/so_you_wanna_go_to_a_canucks_game_eh_faq_for/) - [Canucks Resources](/r/canucks/wiki/resources) - [Meme Hall of Fame](/r/canucks/wiki/memes) - [AMA Archive](/r/canucks/wiki/amas) - [**Nostalgia Corner**](https://www.reddit.com/r/canucks/wiki/nostalgia-corner)     As you can see on regex101 it correctly grabs the 12 lines between ##Players Stats and ##Goalie Stats but when I run the following code in Python None is returned          sidebar = self.r.subreddit(self.SUBREDDIT).wiki['config/sidebar'].content_md         test = re.match('##Player Stats\n(.*?)##Goalie Stats', sidebar, flags=re.DOTALL)         print(sidebar)   sidebar is correctly grabbing the text.


No analytic function in $\{|z|<1\}$ such that $f(0)=1$ and $|f(z)|\ge 1+|z|^2$. Proof strategy

Show there is no analytic function in $\{|z|<1\}$ such that $f(0)=1$ and $|f(z)|\ge 1+|z|^2$. I guess something went wrong along the way and I would like your assistance.   $f$ does'nt get a maximum in the domain, because if it did, it would be constant in the domain, meaning $|f(z)|=1\ge 1+|z|^2$ which doesn't hold for all z. Since $f$ isn't zero in the domain, ${1\over f}$ is analytic in the domain. but $|{1\over f(z)}|\le {1\over 1+|z|^2}\le 1={1\over f(0)}$, which indicates a local maximum making ${1\over f}$ constant, contradiction the fact the $f$ isn't. What am I really lacking here?


In the older versions of blender, you could group objects and they would be treated like one object. In blender 2.8, groups have been replaced with collections. The collections are not treated as one object. How do you select a collection like you would a group?


Should I follow what was mentioned in the “duration of stay” or in the "validity of the visa"?

I'm from Tunisia and I got a Schengen visa from the Austrian Embassy for  28 days, the “duration of stay”, and the number of entries is 1. But the validity of the visa is from 02/08/2015 to 13/09/2015.  Do I have to stay only 28 days, for example from 02/08/2015 to 29/08/2015 or can I stay there until 12/09/2015 ?  And if I have got to stay only 28 days, then can I choose the days of stay, that's mean can I stay in Austria for example from 09/08/2015 to 05/09/2015?


In set theory, we have {x, y, z}, which is the same as {z, y, x} which is the same as ... {y, x, z}, {z, x, y} ... Now, in Lisp (Scheme etc.) a list doesn't allow such juxtaposition. Order matters. Question: Is there a Lisp/Scheme equivalent to an order-doesn't-matter set?  Just guessing, I might simply construct a list, say (x y z), then have some sort of member? i.e., Are you a member of? mechanism.  ...I bet I'm not the only person who's wondered about this...


I am working on a class that makes a callout to a third party API. The third party API needs to be authenticated with a OpenID Connect Auth token. So, in my class, I am making a callout to the OpenID Connect Auth service to get a bearer token and then I am making a callout to the third party API with the bearer token from OpenID Connect API. The third party API is providing some additional information about the fields on the Account object and I am updating the values on the Account object. There are multiple scenarios in this case.  The values on the Account object is different from what is retrieved from the third party API. In this case, the values on the Account object are updated. The values on the Account object is same as what is retrieved from the third party API. In this case, the account is not updated. The third party API returns a blank response. So, the response body contains []. In this case, I am skipping the account.  The apex class is working fine. However, I need some help in building a test class for this. I am sure I need to use MultiStaticResourceCalloutMock stub class to build the test class, but I have some questions around it. My questions are below.  Do I need to write three test methods, one for each scenario? In each of the test methods, I assume I need to use MultiStaticResourceCalloutMock with two end points, one for OpenID Connect Auth and one for third party API, correct? I also need three static resources, one for successful response, one for blank response (the static resource file will contain [] only, and one with the response where the values are exactly same as what is on the Account, correct?  Can someone help?


Questions relating to cables to use 2013 iMac as external monitor to a 2020 27inch imac?

wondering if you can use a late 2013 iMac as an external monitor to a 2020 27inch iMac.i spoke to the office supplies tech guy who recommended a thunder port 2 cable but that fits in the 2013 not the 2020 which is a thunderbolt 3! Can this be done? I know there seems to be all sorts of caveats for different models. What I think I need is a cable with a thunderbolt 3 on one end and a thunderbolt 2 in the other but as they don’t seem to exist...any suggestions would be greatly appreciated!!


How can I filter a MultiPoint Z / xyz points against a 2d polygon

I would like to filter point data from LIDAR scans (3d) by parcel plot lines (2d).  I began with loading the lidar data into microsoft sql and performing a STIntersects between the MultiPoint and the Polygon. This provides a result, but loses it's 3rd dimension.  I then have tried loading the lidar .shp file into the  python library, calling .filter() to narrow down the features, and traversing points checking .within() against the plot line polygon. This seems to work but is super slow.  Next I loaded the lidar .shp into the  python library. However there doesn't seem to be the best 3d support. The methods that were obvious to me were limited by the inability to get a .bound on the shape that included the 3rd dimension. So when I added the shape to the index is complained the bound was 2d and the shape 3d.   Finally I attempted to load each point manually into the rtree index so that I could correct the 3rd dimension manually on the insert.  I have not validated that rtree will even work once I have a complete index.  Has anyone figured out a non brute-force method?


I want to buy a philosophy of mathematics book. I have three options in mind: Philosophy of Mathematics by Øystein Linnebo, Philosophy of Mathematics: Selected Readings by Paul Benacerraf, or The Oxford Handbook of Philosophy of Mathematics and Logic by Stewart Shapiro. My main interests are mathematical platonism and logicism. Do these books cover such topics? If they do, which one, in your opinion, does it better? P.S. Feel free to suggest any other text about Philosophy of Mathematics


Is there a mathematical formula between wire size, current, temperature and wire type(Or resistance)?


I'm writing a script that will automatically sort my albums on my NAS server and encountered the following error. Whenever I have a space in an album name I'm getting an error. Albums can be either called "Artist_-_Album" or "Artist One - Album"    #!/bin/bash   for file in /home/peres/Documents/*   do     name=$(basename "$file")     number=${#name}    #sort if artist and album contains "_-_"      if [[ $name == *"_-_"* ]]     then             echo "Album detected!"             artistname=${name%%_-_*}             albumname=${name##*_-_}             mkdir -p $name/$albumname             mv $name $artistname     fi     #sort if artist and album contains " - "      if [[ $name == *" - "* ]]     then             echo "Album detected!"             artistname=${name%% - *}             albumname=${name##* - }             mkdir -p $name/$albumname             mv $name $artistname     fi   done


Community user id interpreted by absolute value in search

On every use profile page the search bar on the top of the page already contains user:<id> text to simplify search for post of the currently visible user. But this doesn’t work correctly for the  user:        Instead of searching for posts owned by Community user I’ve got Jeff Atwood posts:        In this case minus sign was just ignored and instead of (-1, i.e. Community user), the (+1, i.e. Jeff Atwood) is used. Same happened for any other negative id for the “user:” option in the search box.


Applying to summer research project, should I tell prof about mental health issues to explain poor grades last year?

I'm currently a junior undergrad in a mathematics program, and emailed a prof at a different school if I would be able to apply as a candidate for a summer project he advertised on the school's website. I'm interested in attending this school for graduate work, and mentioned that to the prof.   In his response, he was very excited about my interest in his project (work in ocean sciences) and in the graduate program, and asked if I could send a transcript. I'm very happy about the response, because the prof was very enthusiastic, but due to (what I now know was and is) depression, my grades took a dip, which can be seen in my transcript. For reference, I've done poorly in a mathematics class and computer science class in my sophomore year (2 Cs, and a D in a genetics course, but that's unrelated to this project). Since then, I've gotten Bs in Calc III and Adv Calc (the only other courses relevant so far).   I know this is not a representation of of my ability, as I've done research projects utilizing the material from classes I've done poorly in, and have done well in the projects. At the same time, I don't want to make excuses for myself, and I don't know if it's fair to disclose that information to the prof to make him choose between a candidate like me, and someone else who is "normal".   How should I respond to this? Should I tell him I can't do his project because my grades aren't up to par, or should I try and explain myself?


What do Pentax and Sigma DSLRs offer that differs from Canon and Nikon?

We have a question and answers outlining the . I'm interested in the other DSLR makers, and how the cameras they make compare in terms of significant features, system design philosophy, and unique or interesting photographic capabilities enabled or made easier by these cameras. Likewise, what such things are not handled as well?  Take "the big two have more market share" and the associated advantages of availability, accessibility, and third-party support and documentation .  I'm not interested here in compact cameras, interchangeable-lens cameras with electronic viewfinders, or in rangefinders. (If you're interested in that, though, see )  P.S.: Differences in lens lineups are covered at


Problem - Changing keyboard language layout in Kubuntu 20.04 also changes wide system language

I'm using Kubuntu 20.04 with KDE 5.68.0 and Plasma 5.18.5. I live in Argentina and like to have my OSs in English, but I own a Spanish keyboard. So, I naturally installed Kubuntu in English and then went to System Settings > Input Devices, and at the Layouts tab added a Spanish keyboard layout. Everything worked fine until I rebooted. Now my system is completely in Spanish. But if I go to System Settings > Regional Setting > Language the only shown item is "American English". Even more awkward, if I now add as a new system language "español de España", but not as default language, and reboot, the system returns to English, but some terminal messages and apps (like Crossover) appear in Spanish!! This is driving me nuts. Any ideas??? Edit: Just checked my /etc/default/locale and it has the following content: #  File generated by update-locale LANG="en_US.UTF-8" LC_NUMERIC="en_US.UTF-8" LC_TIME="en_US.UTF-8" LC_MONETARY="en_US.UTF-8" LC_PAPER="en_US.UTF-8" LC_NAME="en_US.UTF-8" LC_ADDRESS="en_US.UTF-8" LC_TELEPHONE="en_US.UTF-8" LC_MEASUREMENT="en_US.UTF-8" LC_IDENTIFICATION="en_US.UTF-8"  sudo locale show this output: LANG=es_AR.UTF-8 LANGUAGE=en_US:es LC_CTYPE="es_AR.UTF-8" LC_NUMERIC=en_US.UTF-8 LC_TIME=en_US.UTF-8 LC_COLLATE="es_AR.UTF-8" LC_MONETARY=en_US.UTF-8 LC_MESSAGES="es_AR.UTF-8" LC_PAPER=en_US.UTF-8 LC_NAME=en_US.UTF-8 LC_ADDRESS=en_US.UTF-8 LC_TELEPHONE=en_US.UTF-8 LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=en_US.UTF-8 LC_ALL=  There are some entries with es_AR, but don't know why is it so.


When I run this program, output is 4 bytes. ( I use a 64 bit compiler)  #include <stdio.h> #include <stdlib.h>  int main(void) {     int *b;     b=(int*)malloc(10*sizeof(int));     printf("%d",sizeof(b));     return 0; }   But shouldn't the output be 40 bytes as I am dynamically allocating 40 bytes of space for 'b'?


I believe that the function: f(x,y)=$\frac{x^{2}y}{x^{2}+y^{4}}$ is continuous on the point (0,0) but i can't prove it.  I know you have to choose something like $x=cy^{2}$(with c a constant) to prove this but it doesn't seem to work. Can anyone help me solve this?


My 18yo niece and I made a contest: who can find more differences between the books and Game of Thrones TV show?  My question is not answered by  - that questions was (and has been closed as being) too broad. My question is more specific and I am focusing only on specific characters and how they are presented/missing/ending. Of course in the broad view the books and TV are different, look at my examples: characters that are missing, characters faith is different and characters that affect the plot, e.g. Lady Stoneheart changes the 4th book which is considered to be the worst of them.   The question  - I am asking also about characters that appear in ASoIaF and does not appear in GoT.  The questions  is limited to S3-S5 while I am asking about ALL Seasons (S1-S7) and ALL the Books.  My question is: Did we miss other characters that appear in the book and not on TV or vice versa?  Here are the differences we found (in no specific order):   Ser Barristan Selmy does not die in the book. On TV Ser Barristan Selmy dies in S5. Tyrion's face is horribly disfigured in the book. On TV Tyrion never loses his nose.  Shae uses Tyrion in the book. On TV Shae loves Tyrion and is even jealous when he marries Sansa Stark. The end of their relationship is the same in the book and on TV. Robb Stark marries Jeyne, Jeyne lives because Robb leaves his wife behind when he goes to his uncle's wedding at the Twins, a move that saves her life. On TV Robb Stark marries Talisa, Talisa dies with him in the Red Wedding. Lady Stoneheart is a zombified Catelyn Stark who kills everyone connected/related to The Red Wedding in the 4th book. On TV Lady Stoneheart is nowhere to be found. Donal Noye serves the Night's Watch in the books. On TV Donal Noye does not exist. Olly is not in the books at all. On TV Olly is a young boy living south of the wall and his village is sacked by wildlings, he joins the Night's Watch and becomes Jon Snow's assistant. Ygritte is killed anonymously in the books and everybody stabs Jon Snow. On TV Olly kills Ygritte and stabs Jon Snow. 'Reek' is Ramsay's servant in the books. On TV 'Reek' is a nickname Ramsay gives Theon. The Hound is killed(?) by one of Gregor's men in the books. On TV The Hound is nearly killed by Brienne. Princess Myrcella is wounded but doesn't die in the books. On TV Princess Myrcella is poisoned and dies. Varys stays in King's Landing in the books. On TV Varys leaves King's Landing. Shireen lives in the books. On TV Shireen Dies (burned to death in S5). Jaime and Cersei (After Joffrey dies) make mutual love in the books. On TV Jaime rapes Cersei in the hall where Joffrey's body on display. Mance Rayder escapes execution in the books, later it is revealed that the burning turns out to be a trickery. On TV Mance Rayder Dies. The Sand Snakes plans are foiled in the book. On TV The Sand Snakes take over Dorne Ramsay Bolton marries and rapes Jeyne Poole in the books. On TV Ramsay Bolton marries and rapes Sansa Stark.   My question is: Does anyone know/noticed other characters that appear in the book and not on TV or vice versa?  My question refers only to specific characters that appear in one but not the other. I am NOT asking for adaptation comparison!


Any way to find what is filling up my disk?

This morning I was greeted with low disk warning on my root partition. So I started with usual investigation path and obviously the result of my first command become the one as shown below.  [root@my-server /]# df -h Filesystem            Size  Used Avail Use% Mounted on /dev/sda3              97G   86G  6.0G  94% / tmpfs                  12G  5.7G  6.1G  48% /dev/shm /dev/sda2             360G   16G  326G   5% /www /dev/sdb1             458G   38G  397G   9% /web /dev/sdc1             458G   42G  393G  10% /server /dev/sdd1             458G   44G  392G  10% /mysql [root@my-server /]# df -i Filesystem            Inodes   IUsed   IFree IUse% Mounted on /dev/sda3            6406144  264687 6141457    5% / tmpfs                3070273     175 3070098    1% /dev/shm /dev/sda2            23928832    1373 23927459    1% /www /dev/sdb1            30457856   52061 30405795    1% /web /dev/sdc1            30457856    1995 30455861    1% /server /dev/sdd1            30457856     793 30457063    1% /MySQL   But I wanted to know who is taking that much space and fired up disk usage and found,  [root@my-server /]# du -shx / 24G / [root@my-server /]# du -h --max-depth=1 / 1.6G /root 4.0G /home 14M /sbin 6.5G /var 0 /misc 12K /.dbus 4.0K /mnt 4.0K /media 5.7G /dev 4.8G /opt 0 /sys 52M /user 35M /etc 0 /net 4.0K /bak 43G /mysql 6.5G /usr du: cannot access `/proc/3633/task/25117/fd/78': No such file or directory du: cannot access `/proc/3633/task/7047/fd/70': No such file or directory du: cannot access `/proc/24882/task/24882/fd/4': No such file or directory du: cannot access `/proc/24882/task/24882/fdinfo/4': No such file or directory du: cannot access `/proc/24882/fd/4': No such file or directory du: cannot access `/proc/24882/fdinfo/4': No such file or directory du: cannot access `/proc/24883': No such file or directory 0 /proc 244M /lib 4.0K /nas 4.0K /selinux 4.0K /srv 27M /lib64 42G /server 49M /boot 16G /www 16K /lost+found 38G /web 100M /tmp 8.9M /bin 168G /   whoops, the actual usage being around 30GB, how do I find what files are eating my disk?  Confirming to the suspicion the culprit was a deleted file, Nothing like find or du could resolve the offending file if the file doesn't exists! well, te actual sequence of actions to find it were,  [root@my-server ~]# lsof / | grep deleted ... java  3633  wwwuser  1w  REG  8,3  66975347588  396715  /home/wwwuser/apache-tomcat-7.0.29/logs/catalina.out (deleted) ...   whoops, a 62GB file, now,  [root@my-server ~]# cd /proc/3633/fd/ [root@my-server fd]# ll | grep deleted [root@my-server fd]# > 1   Well, the above commands I figured out from another SO answer at  but I was wondering wat was that last command? How did it reclaim the orphan disk space?


Want Some Hint on a Proof of an Inequality by Induction

The problem comes from a problem sheet of an introductory math course by Oxford. It is question 1 in . I don't study there I'm just curious and want to try. Given $n$ positive numbers $x_1, x_2,\ldots,x_n$ such that $x_1+x_2+\ldots+x_n\le 1/3$, prove by induction that $$(1-x_1)(1-x_2)\cdot\ldots\cdot(1-x_n)\ge 2/3.$$ My attempt: For $n=1$, $$x_1\le1/3$$ $$-x_1\ge-1/3$$ $$1-x_1\ge1-1/3$$ $$1-x_1\ge2/3$$  (Incorrect) Assume $(1-x_1)(1-x_2)\cdot\ldots\cdot(1-x_k)\ge2/3$ for some $k$. For $n=k+1$, $$ \left\{  \begin{array}{c} x_1+x_2+\ldots+x_k\le1/3\qquad(1)\\  x_1+x_2+\ldots+x_k+x_{k+1}\le1/3\qquad(2)  \end{array} \right.  $$ $(2)-(1):$ $$x_{k+1}\le0$$ $$-x_{k+1}\ge0$$ $$1-x_{k+1}\ge1$$ Then$$(1-x_1)(1-x_2)\cdot\ldots\cdot(1-x_k)(1-x_{k+1})$$ $$\ge2/3\cdot1$$ $$\ge2/3$$ But it looks like a paradox because $(1)$ and $(2)$ can't be true at the same time. For $n>1$, I cannot make the given inequality into the desired one. They are just not equivalent.  I'm looking for a hint. Sorry but I think they are not grading it now. Thank you. Edit: Reply to Kavi Rama Murthy: When $n=2$, $$x_1+x_2\le1/3$$ $$1-x_1-x_2\ge2/3$$ Then $$(1-x_1)(1-x_2)=1-x_1-x_2+x_1x_2$$ $$\ge(2/3)+x_1x_2$$ $$\ge2/3$$ For $n=k+1$, given that $$x_1+x_2+...+x_k+x_{k+1}\le1/3$$ and apply the $n=k$ case with $x_1,x_2,...,x_k+x_{k+1}$, $$(1-x_1)(1-x_2)\cdot\ldots\cdot(1-x_k-x_{k+1})$$ $$=(1-x_1)(1-x_2)\cdot\ldots\cdot[(1-x_k)(1-x_{k+1})-x_kx_{k+1}]\ge2/3$$ Then $$(1-x_1)(1-x_2)\cdot\ldots\cdot(1-x_k)(1-x_{k+1})\ge2/3+x_kx_{k+1}(1-x_1)(1-x_2)\cdot\ldots\cdot(1-x_k)$$ $$\ge2/3$$ Reply to ΑΘΩ:  (Replaced with the empty $I$ case) When $I$ has $1$ element, $${\displaystyle \prod_{i\in I}^{1} (1-x_i)}=1-x_i\ge1-{\displaystyle \sum_{i\in I}^{1} x_i}$$  When $I$ has $0$ element, $${\displaystyle \prod_{i\in I}^{0} (1-x_i)}=1$$ Looking at RHS, $$1-{\displaystyle \sum_{i\in I}^{0} x_i}=1$$ Then $${\displaystyle \prod_{i\in I}^{0} (1-x_i)}\ge1-{\displaystyle \sum_{i\in I}^{0} x_i}$$ Assume ${\displaystyle \prod_{i\in I}^{k} (1-x_i)}\ge1-{\displaystyle \sum_{i\in I}^{k} x_i}$. When $I$ has $k+1$ elements, $${\displaystyle \prod_{i\in I}^{k+1} (1-x_i)}$$ $$=(1-x_{k+1}){\displaystyle \prod_{i\in I}^{k} (1-x_i)}$$ $$\ge(1-x_{k+1})(1-{\displaystyle \sum_{i\in I}^{k} x_i})$$ Looking at RHS, $$1-{\displaystyle \sum_{i\in I}^{k+1} x_i}$$ $$=1-{\displaystyle \sum_{i\in I}^{k} x_i}-x_{k+1}$$ $$=1-x_{k+1}-{\displaystyle \sum_{i\in I}^{k} x_i}$$ $$=(1-x_{k+1})(1-\frac{{\displaystyle \sum_{i\in I}^{k} x_i}}{1-x_{k+1}})$$ Since $1\ge1-x_{k+1}$, $$1-\frac{{\displaystyle \sum_{i\in I}^{k} x_i}}{(1)}\ge1-\frac{{\displaystyle \sum_{i\in I}^{k} x_i}}{(1-x_{k+1})}$$ $$(1-x_{k+1})(1-{\displaystyle \sum_{i\in I}^{k} x_i})\ge(1-x_{k+1})(1-\frac{{\displaystyle \sum_{i\in I}^{k} x_i}}{1-x_{k+1}})$$ $${\displaystyle \prod_{i\in I}^{k+1} (1-x_i)}\ge1-{\displaystyle \sum_{i\in I}^{k+1} x_i}$$ In the problem, given ${\displaystyle \sum_{i\in I}^{k+1} x_i}\le1/3$, $${\displaystyle \prod_{i\in I}^{k+1} (1-x_i)}\ge1-(1/3)$$ Then $$(1-x_1)(1-x_2)\cdot\ldots\cdot(1-x_k)(1-x_{k+1})\ge2/3$$


Determine the number of lines within a text file

Is there an easy way to programmatically determine the number of lines within a text file?


Animation movie (80's-90's) with brain-sucking insects

I'm looking for a movie I've seen as a kid, the details are foggy and sparse but I'll try my best following :  What is it?: An animated movie. Tell us what it isn't: It is not . Tell us what made it memorable: A planet where some brain-sucking insect-like aliens live, also an old bald man lives on the same planet. When did you see this film?: Late 80's, early 90's. How old was it?: If I've seen the movie on TV in Spain, is a pretty safe bet that it will be at least 5 years old. Was it part of a series?: I don't think so. Plot: No clue, sorry. What language was it in?: The movie was dubbed to Spanish (Spain).  No detail is too insignificant  What details can I recall?:  Sci-Fi story with one character being an old bald man living on a planet where some insect-ish aliens can open your skull and suck your brain. Habitat of those insect-ish foes was depicted in light blue colors, I kinda remember giant mushrooms as well. A young boy befriends the old baldie, the boy came to the planet with some adults.   Other details I'm not completely sure (maybe my mind is filling the gaps):  I think that the movie was drawn using , not 100% sure though. I cannot remember which year I've seen the movie, but it should be late 80's or early 90's. I'm pretty sure that I've seen the movie in Spanish TV (not rented videotape). Somehow the young boy was the young version of the old baldie (time travel?). The old man lives in a wood house near the brain-sucking insect habitat, as many old man does he spend his time on the porch.    Try to offer unique details As anyone would expect from this kind of movie, there's a scene where the alien insects attack a group of people trying to suck their brains. A young boy was with those adults and survived with injuries in his head. The old bald man have some surgery in his head due to an attack he suffered years before.


How to run native Windows 10 apps on startup?

My goal is: run some native Windows 10 apps at startup time  The way I would do it with an installable app is right click on the app from then start menu, go to containing folder and then make a shortcut to the executable file   in shell:startup but there is no such an option to go to containing folder for apps installed from Microsoft store


Single Threaded Qaud Core v.s Hyper-Threading Dual Core

Let's say we have two CPUs, One is Quad Core 3.2 Ghz with 4 Cores, and We have a Dual Core 3.2 Ghz with 2 Cores with 2 threads in each Core (Hyper-Threading). My assumption as a programmer will be, the 4 cores 4 threads should perform faster than 2 cores 4 threads since the second CPU needs to switch between threads in order to emulate 4 cores while the first one doesn't need to perform such switching as each core can perform independently and individually.   I want to confirm that my assumption is true, if not please explain why one is better than the other.


I bought a new inner tube and when I tried to inflate it, the tube got unevenly inflated (check picture). This is the first time I'm installing a tube by myself so I don't know if this is normal. Do you think this is this a production defect, or did I do something wrong while pumping the tube? Can I fix it by myself?


Run a batch file whenever a file in Dropbox is updated

I need to get a batch file which is stored on my Windows PC hard drive to automatically run whenever a file in one of my Dropbox folders is changed.  How can I accomplish this?  Note:  The amount of times that files change are very inconsistent.  So running it on a timed schedule will not work efficiently in this case.  Edit:  The answer to the question is this is marked as a duplicate of does not answer how to check when files are changed, it checks for files being created.  I need guidance on what to do to run a batch file when a file in a folder is modified.


i just don't understand why I have a nullpointerexception with this:  public class MainActivity extends AppCompatActivity {  private EditText field;  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);      EditText field = (EditText) findViewById(R.id.field);     Button plus = (Button) findViewById(R.id.plus);     Button moins = (Button) findViewById(R.id.moins);     Button ctof = (Button) findViewById(R.id.ctof);      plus.setOnClickListener(buttonclick);     moins.setOnClickListener(buttonclick);     ctof.setOnClickListener(buttonclick);  }   private View.OnClickListener buttonclick = new View.OnClickListener() {     @Override     public void onClick(View view) {         switch(view.getId()){             case R.id.plus:                 //TODO                 Toast.makeText(MainActivity.this, field.getText().toString(), Toast.LENGTH_LONG).show();                 break;         }     } };   }   I don't understand my mistake, it's simple and I don't know where is the issue. I can't get my field and print the result.


Supervisor has suprevisees do peer reviews for them – what are the ethics of this?

From :  Not everything in Jan’s lab was bad and I think it’s also important to point out that my relationship with Jan was often professionally respectful. For example, Jan repeatedly asked me to peer review manuscripts that he had received from various journals from all impact levels. The level of trust was high. Jan would give me his log-in and password. Our routine was that I’d submit reviews for manuscripts without him reading either the manuscript or the review that I wrote; it was completely hands-off. Honestly, I quite enjoyed this, although my work was always claimed in Jan’s name.  The scientist in question seems to see little wrong with that. Can you provide an ethical analysis of this behaviour?


Which is the right explanation for rocket motion?

What actually causes a rocket to move? Is it the pressure in the rocket engine or the amount and velocity of mass that is being ejected out.  The reason I am asking is, I found these two explanations for a rocket motion. Are they same or different. If same, is there any correlation between them?


Does %* in batch file mean all command line arguments?


Journal rejected my paper because contents of paper are in PhD thesis

I have submitted a journal paper to a journal four days ago and today I received an email informing me that it has been rejected. The only reason for this is: "About 70 % of the article is similar to other documents". I know my paper and I know that I haven't copied it from anywhere else. There is a conference version of the paper, but it is different, plus it is 6 pages long, while the journal is 15 pages long, so since 6/15 = 40%, it doesn't add up to 70%, and this is not the reason for rejection. The real reason is that my PhD thesis is available online (it is mandatory at my university to add it to an open repository if I want to graduate). I graduated 3 months ago, and in fact the last chapter of my thesis consists in the paper that was rejected now. However, I was always told both by my supervisor who is a full professor with 25 years of experience (and Associate Editor of top-notch journals) and by many other people that it is not a problem to submit a paper based on an already published PhD thesis, as journals should not consider the thesis as a paper. Therefore, I am very surprised by the decision made by the editor. What should one do? Wait to graduate until the paper is accepted? That is simply ridiculous. Has this occurred to any of you? Do you know how journals behave in this case? I once reviewed a journal paper which was literally copy-pasted from a chapter of a PhD thesis of a student. I contacted the editor who had sent me that paper asking what to do and he mentioned that it is a standard and common practice and it shouldn't be considered self plagiarism. So, once again, I am very surprised by the decision made. EDIT: as asked in the comments, here is the email I sent to the editor: Dear Professor XYZ, I am contacting you regarding the submission of my paper to the journal ABC123. As in the subject, the reference number of the manuscript is XXXYYYZZZ. Today I have received an email notifying me that my paper (submitted only 4 days ago) has been rejected. You may find the email attached to this email. The reason for this is: “About 70 % of the article is similar to other documents”. The possible reason for this very high similarity is threefold:  I have published a related conference paper before, containing preliminary results and much less content in general. However, that conference paper is 6 pages long, while the paper submitted to ABC123 is 15 pages long. Therefore, it is mathematically impossible for the conference paper to be the reason of the > 70% similarity, since 6/15 = 40%; The paper has been uploaded on arXiv. This was done the same day in which I sent the paper to your journal. However, this is allowed by Elsevier, as explained here; The contents of the paper are part of my PhD thesis, in particular, of Chapter 5. This is what probably results in the highest similarity, as the article submitted to your journal is based on this chapter. However, Elsevier’s policy with respect to PhD thesis is the following: “Elsevier does not count publication of an academic thesis as prior publication”.  I have run a plagiarism check myself, you can find it attached to this email. This confirms what I have said so far: the similarity of my article is related to my PhD thesis, not to any other previously published works. Given the above explanations, I would kindly ask you if you could reconsider your decision. The plagiarism check returned indeed a similarity higher than 70%, but, as explained above, this is most likely related to my PhD thesis. However, Elsevier does not count PhD thesis as prior publication. Therefore, my paper submitted to ABC123 respects Elsevier’s policies and should therefore be considered a new publication. Thank you for your consideration. Best regards, cholo14


Convert float to std::string without losing precision. Also I don't want to use sprintf

I want to convert float value i.e 3.14159267 in std::string I don't want to use sprintf  #include <iostream>   // std::cout #include <string>     // std::string, std::to_string  int main () {   std::string pi = "pi is " + std::to_string(3.14159267);   std::cout<<pi<<std::endl;   return 0; }   I got result as      3.141593


Five girls stand in a line. How many possible permutations are there in which Anya is at the left of the line or Elena is on the right, or both?

Five girls, Anya, Beth, Carol, Dasha and Elena, stand in a line. How many possible permutations are there in which Anya is at the left of the line or Elena is on the right, or both? If we want Anya to be at the left she must occupy the first or the second place in the line (starting from the left). That would be 24 possibilities each place, 24+24=48 The same thing applies to Elena as she should be in either one of the two places at the right side, so there are 24+24=48 possibilities for her too If we want Anya to be at the left and Elena to be at the right at the same time, we find that there are 4 combinations: A _ _ E _, A _ _ _ E, _ A _ E _, _ A _ _ E, And each one represents 6 possibilities, therefore 6x4=24 Adding all the results 48+48=96, and subtracting the 24 that are already included there, the answer would be 72 but the book says 42


Why human skin colour disprove natural selection?

Amount of melanin decides the darkness and fairness of skin. The darker the skin is, larger the heat energy it will absorb from sunlight. The lighter the skin is, less will be the heat energy absorbed. The people in cold regions of world should have darker skin to absorb much heat available. And people in hot climate should have reflexive white skin to reflect much heat from sunlight. But here's exactly opposite of it. Why?


How to get cleveref to explicitly list each reference rather than joining them?

I am using cleveref's \cref{label} command with multiple arguments. I want to ensure that it explicitly lists all three sections that I am referencing regardless of if they are in order or not.  At the moment they are referenced as "sections 1 to 3" with the 1 and 3 being hyperlinked.  I need all three listed something like "sections 1, 2 and 3" with all digits hyperlinked so that the reader can click through directly to section 2.  I am using hyperref for the links (and I've put the \usecommand{cleveref} after the one for hyperref).


failed to download package files check internet connection

i recently installed ubuntu 12.04 by wubi installer.By giving right details of proxy in firefox i am able to access internet but when i try to download something ,ubuntu gives the error "failed to download package files check your internet connection.". How should this error be resolved?


Short story about interstellar travel gone wrong

Trying to find a story I read a couple of years ago in an anthology, not sure when the story dates from but likely to be recent - the last decade or so.   The story has passengers travelling between stars via a series of jumps. The calibration of the drive is affected by a special metal, any of which has to be stored in a shielded compartment (I think the jumps were measured in 'degrees'). One of the passengers unwittingly takes some of this metal on board, which throws off the calculations for the jumps, and they jump into an alternative universe where there are no signs of any humans ever existing. They start to try to reverse their steps to get back to the known universe, but the reverse calculation seems impossible.  That's as much as I read of the story before I lost the book. After many dreams (feverish nightmares!) re-living this story, I need to know how it ends. I know it's not much to go on. The story name, author, or the anthology it appears in would be fantastic.


Transfer pokemons to willow in Pokemon GO

Just wanted to ask if I accidentally transferred my Pokemon to Willow, Will I receive candy if I don't have that kind of Pokemon in my collection?


Prove combinatorically, that for $n \geq m$: $\sum_{k=0}^m \dbinom{n}{k} \dbinom{n-k}{m-k}= 2^m \dbinom{n}{m}$

Prove combinatorically, that for $n \geq m$:   $$\sum_{k=0}^m \dbinom{n}{k} \dbinom{n-k}{m-k}= 2^m \dbinom{n}{m}$$   The right hand side tells that us the number of ways we can pick either white or black $m$ balls from a total of $n$ balls. But I'm not sure what the connection between that and the left hand side is.


Why it is called "Linear" Differential Equation?

$$y'+P(x) \cdot y=Q(x)$$  Why it's called Linear Differential Equation? The function y might be curved.


How can I reset permissions on (sub)folders under Windows Vista?

I'm running Windows Vista, which is installed on my primary drive.  I have a second hard drive installed, which used to host my Windows XP install, and I'm trying to delete the Documents folder, but I don't have permissions to do so.  Is there a way I can reset the permissions on all subfolders of my second drive?


Trouble with sum of inverse integers vs. inverse of sum of integers

I'm having trouble trying to show the following:  $$ \frac{1}{r_{1}}+\dots+\frac{1}{r_{v}} \ge \frac{v^{2}}{r_{1}+\dots+r_{v}} $$  where  $r_{i}>1$ for all i and $r_{i}$ are not necessarily equal. And:  $$v=\frac{n}{r}\;;\;n=\sum_{i}r_{i}=rv$$ $$r= \frac{\sum_{i}r_{i}}{v}$$  I've run multiple simulations which all show that the required result is true. I've been able to show that the RHS has a larger denominator but also a larger numerator; which left me stuck trying to show that the effect of the denominator dominates.


What do we call the entire project which is based on arranged kinetic actions?

I love that concept whenever any company comes up with it as a part of their marketing campaign but not sure what do we call such action.   The action starts with one tiny thing (say striking a small metal ball) and it hits another thing that swings further and does some action. The beauty continues and finally a big gate may open showing some message/greetings. So, a small tiny ball to a giant gate everything happens kinetically.    and  are two videos showing the action which is brilliantly crafted. I know the word '' but I've always used, heard and seen the phrase in a different context. Even the dictionary uses an example that does not fit to my concern.


Why I have lack of space in root directory?

Using OS Ubuntu for 2 days. Everyone says that 8GB is more than enough for root directory but it seems like so soon I will have critical lacks of space in root. I have 256GB hard drive and has distributed space as follow:   10GB for / 8GB for linux-swap 126GB for /home   I thought that root "/" directory needs only for install OS and nothing more so that "/home" is intended for my software, but it seems like my software is placed in "/" directory whenever I install new program. The question is: should I reinstall my OS and allocate more space for "/" directory or I don't understand something because now I have only 2GB free from 10GB of root directory, and I'm afraid when I'm going to install more software it's gonna be full?


I have a for loop with a map like this.  std::map<int,std::string> mymap = {{1,"a"},{2,"b"},{3,"c"}};  for(std::map<int,std::string>::iterator it = mymap.begin(); it!=mymap.end(); ++it) {     if(it->first==3)     {         mymap.erase(it);     } }  std::cout << mymap.rbegin()->second << std::endl;   The output is "b" as expected. The question is: Can this lead to an infinite loop (or a crash) somehow? I mean after  erase(it)   the iterator it is invalid. If the erased item was not the last one, it should be ok, because "it" is incremented after the erasion and when the condition is evaluated it points to mymap.end() at max. But if I erase the last one, after erasion mymap.end() should be after the last remaining item, and then it is incremented anyways. Can't it somehow run out of range? Shouldn't I use something like  for(std::map<int,std::string>::iterator it = mymap.begin(); it!=mymap.end(); ++it) {     std::map<int,std::string>::const_iterator tempit = it;     const bool lastItemErased = ++tempit == mymap.end();      if(it->first==3)     {         mymap.erase(it);     }      if(lastItemErased) break; }   to be safe?  note: both of the above runs and behaves as expected if I try to erase the element with key 3 and 2. I don't see how is this possible and why doesn't it crash. How can I increment an invalid iterator?  update: It has to work with c++03. I initialized the map like this, to post the question more easily.


PUA:Win32/Vigua.A => GC.Communcator.exe unknown windows defender detected threat

Does anybody know what this is or might be, I have heard the name Proffessor "Eric Laithewaite" before as I have watched some of his electronics videos on Youtube and possibly downloaded some PDF Schematics, a few image files or some PDF's for later viewing or research. I also may have downloaded some content as a whole webpage via firefox with save html complete page But I don't actually remember doing the later.. Has anyone come across this before either GC.Communicator.exe or PUA:Win32/Vigua.A; I'm running a 64 bit system not 32 so not entirely sure where it has came from,  Wanting to know if this is a usefull program in any way ie, electronics control from browesr or any other firmware that may interface with motors, audrino, rasberry etc.. Have four options: leave it wher it is; Shread it with bleachBit; uSe older versions of malwarebytes, AdwareRemovalTool or JRT to try and detect it; Quarantine it; Just thought I'd post it here and see if anyone has come accross it..


Is there a way to change the ubuntu login background wallpaper to a video?

I've been a bit obsessed with customizing Ubuntu. I have a really cool logo animation in a mp4 file. I'm trying to use that video as my login screen background，like Dreamscene in Windows. But I'm not sure how to accomplish that.  I Googled relevant information and noticed that LightDM can change login background to another image. I haven't seen any program that can make the login background a video though.


ethernet wall socket - are they all the same?

so the house already has some ethernet wall sockets which I believe were installed when 100Mbps was more common. The cable current in used seemed to indicate that's it's not gigabit capable. I want to rewire it to CAT6. Do I need to change the sockets as well?  I looked at eBay at several wall sockets supposedly designed for CAT6 but I can't see any difference to my untrained eye.  Thank you for the help. :)


Trouble with nvidia drivers on Asus ROG GL522

I was installing ubuntu-Gnome 16.04 on my Asus ROG GL522VW laptop with an nvidia GTX 960m graphics card, and stumbled upon a problem.  After installation, I don't even get to the login screen. Instead my screen just freezes. I had this problem before, and got my answer in this post:   So I booted with nouveau.modeset=0, and everything boots just fine. But after I use additional drivers to install the NVIDIA binary driver - version 361.42 from nvidia-361 (proprietary, tested), I only get a black screen when I try to boot regardless of whether nouveau.modeset=0 is set or not.  While the screen is black, when I try to access the command line with ctrl + alt + f1 all I get is this: A start job is running for Hold until boot process finishes up (Xmin Xs/no limit) and no matter how much I will wait, it doesn't end and I have to reboot.  I followed the instructions in this post:   When I boot after reinstalling everything and choosing lightdm - it basically works but my login screen looks like a unity login screen, and when I insert my credentials it shows me a very bugged screen with all kinds of broken images with some of the things I had on my last boot, and after a few seconds my screen flashes on and off and it boots into my normal desktop, but still keeps spitting out system problem detected with only the option to close or report.  Also tried to install nvidia-355 and all kinds of versions, with no luck.  I wouldn't mind working with nouveau.modeset=0, but as far as I understand this disables my graphics card and doesn't utilize all of it's potential?  Any help or insight will be greatly appreciated. Sorry for the long post and if I should include more information please tell me what else I should include.  A huge thanks up front!  Edit: Reposted this question again and didn't know I can just edit the question to get it back up.  Edit2: Bumping again in a last effort to solve this issue  Please let me know if it is lacking information.


So I have a text block something like below,  #start Line 1 Line 2 Line 3 #end  *--Similar blocks-*   I used this   Regex.Matches(text,@"#start(.*?)#end",RegexOptions.Multiline)   regex for this above block.  The thing is when I try matching this Regex through Notepad++ find options it works, but through C# Regex.Matches function it fails.  I don't know what exactly is the problem. But hope you people can help me ! :)


Syrian citizen with valid Schengen visa and KSA residency - Turkish visa needed?

I'm a Syrian citizen, travelling from Paris to Turkey and Saudi Arabia. Do I need a Turkish visa? I have valid residency in Saudi Arabia and a Schengen visa.


Why the limit of the following sequence is like this:  $$\frac{2 \sqrt[n]{n!}}{n}=\frac{2}{e}$$


In X-Men: The Last Stand Professor X dies, so how is he alive in X-Men: Days of Future Past? That makes no sense if he dies before they reach that future.


Why $\int_0^\infty e^{-t}\log tdt =-\gamma$?

What is $$\int_0^\infty e^{-t}\log tdt?$$  Plugging into  yields that it's $-\gamma$, where $\gamma$ is Euler's constant. How can we get it? Maybe by some contour integration?


It would be nice to have possibility to access favourite questions for each community site from Android app.


An asker on a question I am working on posted some code that contains their site password if you look deeply at it. How can I alert the user to take this down without posting it publicly on the question, thus calling even more attention to it?


On the top of most cameras is a selector knob which will allow you to select different modes. These range depending on the camera, my camera (Nikon D5100) has several choices.   I have been told conflicting things about which mode to use. From my understanding most DSLRs have M (Manual) S (Shutter Priority) A (Aperture Priority) P (Program Mode) and possibly Auto mode.  Some models (specifically entry level) have other modes some of which could be Night, Macro, Landscape, Portrait, etc.   I have been told by one person to use all available modes the camera has to offer as I learn more about photography.  While another person said only use M, S, A, P modes and avoid all the rest while you learn.  Which of the statements is generally more correct?  A few notes: I have every intention and am currently attempting to learn as much as possible about the camera and how to capture great photos but I am a beginner. I shoot in RAW most of the time. And I want to capture the best possible shot with the camera (not have to process it in post extensively to get the best shot).


Why do they need "16 female, 7 male" to re-establish Zion?

So, re-reading this:     After which, you will be required to select from the Matrix 23 individuals - 16 female, 7 male - to rebuild Zion.   It got me thinking - why exactly this ratio (and why exactly on that scale)?  Is it based on some out-of-universe scientific research for optimal seed population? Was there some in-universe explanation for the peculiar non-1-to-1 ratio?  I am fine with out-of-universe answers, but would prefer those backed by specific data (or in-universe answers based on canon material, or words from franchise workers), as opposed to pure unfounded guesses.


Proving that there is a perfect square between $n$ and $2n$

Problem: Prove that there is at least one perfect square in the sequence $n, n+1,\ldots, 2n$.  I know this is in fact very easy, but I can't seem to put my finger on the right equation for it. It involves something like $2(n+1)^2 <(2n)^2$ or the like.


What purpose do intersection points serve when mapping?

In  you will notice a ring of intersection points, all circling the focal land mass of the map. What are these intersections used for? I assume they are meant to guide the cartographer, but how do they work? What determines how the intersections of lines are placed?


How does scope work in this Javascript code?

I'm reading a Javascript (ES6) book, and in Chapter 7 (Scope) there's an obscure example (at least for me as a beginner) that I can't wrap my head around.  const f = (function() {             let count = 0;             return function() {                 return `I have been called ${++count} time(s).`;                 }             })();  f(); // "I have been called 1 time(s)." f(); // "I have been called 2 time(s)." //...   So, the count variable is initialized at 0 but, why is the value of it still "alive" in subsequent calls to the f function? is the first unnamed function still valid behind the scenes somewhere in memory or anything like it?


Let $y=3x-8$ be the equation of tangent at the point $(7,13)$ lying on a parabola, whose focus is at $(-1,-1)$. Evaluate the length of the latus rectum of the parabola.     I got this question in my weekly test. I tried to assume the general equation of the parabola and solve the system of equations to calculate the coefficients with the help of these given conditions. But this way it becomes very lengthy and tedious. Can anyone provide an elegant solution? Thanks.


how to create dynamic graphics in latex beamer

How can I create a dynamic graphic in latex beamer?. for example, I want to display curves in the same graphic one by one, I mean one at a time. Thanks


Homology of a compact manifold is finitely generated

Perhaps this is obvious and I am overlooking something, but why are the homology groups of compact manifolds finitely generated?


Consider, for example, $\frac{1}{N} = \frac{1}{195} = \frac{1}{3\cdot5\cdot13} = 0.0051282051282051282... = 0.0\overline{051282}$, compared to, say, $\frac{1}{N} = \frac{1}{77} =  \frac{1}{7\cdot11} = 0.012987012987... = 0.\overline{012987}$. QUESTION: Under what conditions will the repetend of $1/N$ include all of the zeros following the decimal point, such as in the example $\frac{1}{77}$? Is there a particular class of integers $N$ which this must always happen? I have noticed that this seems to be the case when $N$ is a semiprime, but it is not the case, as we see above, when $N$ has three prime factors.


How do you tell if a D&D book is 3.0 or 3.5?

I'm new to d20. I recently acquired a bunch of D&D books and I'm sure they are all either 3.0 or 3.5, but it doesn't say in the book which version it is. How can I tell which version the book is?  For instance, I have "Complete Warrior - A Player's Guide to Combat for All Classes". It's hard back, published in '03. Is it 3.0 or 3.5?  Another example, I have "Sword and Fist - A Guidebook to Fighters and Monks". Perfect Bound, published in '01. Is it 3.0 or 3.5?


How to search for upcoming conferences that will be held in a specific subject

What is the best way to search for conferences all over world? I need to participate in one in the near future.


Prove there is no such nth root of unity $\zeta$ such that $\mathbb{Q}(\sqrt[3]{2}) \subset \mathbb{Q}(\zeta) \quad$

I'm trying to do the above problem. My approach is to use the fact that $\mathbb{Q(\zeta)}$ is the fixed subfield of the normal subgroup $A_3$ of $S_3$ and then since $A_3$ has no subgroup of the form $\{1, \tau\}$ for some transposition $\tau$, then $\mathbb{Q}(\sqrt[3]{2}) \subseteq \mathbb{Q}(\zeta)$ cannot happen since $\mathbb{Q}(\sqrt[3]{2})$ is the fixed subfield for the subgroup $\{1, \tau\}$. I'm not sure if this correct but I think the proof is supposed to be along these lines. Thanks.


What am I doing wrong with my linux commands?

I want to inherit every new file from my group so that I can have execute permissions, and no one else, but when I try to create new ones, it gives me 664 permissions how can I fix this??  sudo adduser $USER cyber_espionage   sudo chown $USER:cyber_espionage ~/Documents/tool sudo chmod 775 ~/Documents/tool sudo chown $USER:cyber_espionage -R ~/Documents/tool sudo chmod 2700 -R ~/Documents/tool sudo find ~/Documents/tool -type d -exec chmod 775 "{}" \; sudo find ~/Documents/tool -type f -name "*.py,*.sh" -exec chmod +x "{}" \; sudo find ~/Documents/tool -type f -name "*.sh" -exec chmod +x "{}" \;


$\sum_{n\ge0}f\left(n\right)x^{n}=\frac{1}{\sqrt{1-2x-3x^{2}}}$, where $f(n)$ the $n$-th coefficient of $(1+x+x^2)^n$

Let $f\left(n\right)$ denotes the n-th coefficient of $\left(1+x+x^{2}\right)^{n}$. Show that $$f\left(n\right)=\sum_{k=0}^{\left\lfloor \frac{n}{2}\right\rfloor }\binom{2k}{k}\binom{n}{2k}.$$ Then show that $$\sum_{n\ge0}f\left(n\right)x^{n}=\frac{1}{\sqrt{1-2x-3x^{2}}}.$$  I have managed  to answer the first question, but I find it hard to procced on the second one. I have found (by using the Binomial Theorem) that $$\sum_{n\ge0}\left(\frac{1}{2^{n}}\sum_{k=0}^{\left\lfloor \frac{n}{2}\right\rfloor }3^{k}\binom{2n-2k}{n-k}\binom{n-k}{k}\right)x^{n}=\frac{1}{\sqrt{1-2x-3x^{2}}}$$ but I can't somehow prove that $$f(n)=\frac{1}{2^{n}}\sum_{k=0}^{\left\lfloor \frac{n}{2}\right\rfloor }3^{k}\binom{2n-2k}{n-k}\binom{n-k}{k}$$ even though it seems, it holds. I also tried to show that, for $n\ge2$, $$c_n=2c_{n-1}+3c_{n-2},$$ where $c_n=\sum_{k=0}^{n}f\left(k\right)f\left(n-k\right)$, in order to show that $$\left(\sum_{n\ge0}f\left(n\right)x^{n}\right)^{2}=\frac{1}{1-2x-3x^{2}},$$ but again I failed miserably! I also tried some other ideas, but nothing seems to work. Any suggestions? Thank you for your time! :)


Can it be a correct grammar? 'Don't go nowhere'

I heard it expressed on gotel radio station;  "Don't go nowhere" can it be correct?


TikZ borders showing through when they shouldn't (overlapping circles)

If you draw two circles that are exactly the same in all aspects (location, size, etc...) except they have different colors, then the "border" of the underlying circle is showing through.  \documentclass[10pt]{book} \usepackage{xcolor} \usepackage{tikz}  \begin{document}  \begin{tikzpicture}     \fill (0,0) circle (0.1);     \fill[color=red] (0,0) circle (0.1);     \fill[color=red] (0.5,0) circle (0.1); \end{tikzpicture} \end{document}   Notice the first circle has a black "edge" around it that looks different than the 2nd circle which doesn't.   The problem is due to the fact that one is anti-aliasing both circles and the edge colors are being blended.   Is there a way to fix this but still have anti-aliasing? (basically render all the objects I need then anti-alias them properly afterwards?)  (I realize TikZ probably can't do anything about this but one doesn't know unless they ask)


How do I disable a bottom panel with the list of open windows on GNOME 3?

How do I disable "Workspace dock" (a bottom panel with the list of open windows and a workspace indicator-cum-switcher), the one that is over "Plank" in the screenshot below?    I'm using Ubuntu 17.10.


Dust on Sensor After Many Cleanings DSLR

I know there have been a lot of posts on this topic, but I haven't found exactly what I am looking for.   I noticed some dust spots on my sensor for my D750 after I took a picture with some sky in it and then was playing around with "dehaze" in Lightroom. Okay no problem, I have owned the camera for a year probably time to clean the sensor.   So I do a bit of research online and land on the fact that I can do this myself. I also want to learn how so I don't need to spend $50 or $75 each time I need this done. I decide to buy .  What I do is close my aperture down to F22, put my ISO on 100 and then set my shutter speed to 2 seconds or so and take a picture of a well lit white piece of paper.   I then go into Lightroom and jack the dehaze and look for dust spots. I see a ton. Okay, so now let's clean it. I wet the swab with a few drops to get it just saturated on the top of the swab, apply some pressure, wipe left to right, turn it over, wipe right to left and done.   Then I took the same picture and although the dust spots are different, they are still there! What the heck? Okay maybe it just needs a good blow out. I took my  and blow out everything I can inside of there, then I do the same cleaning method as the first time, except this time I start with a dry swab, throw it out, then get a new swab, wet it and clean it again.  I take the picture again... and they are STILL THERE. Okay let's get out the high power flashlight. I wouldn't say I scrubbed it, but I went back and forth with the swab on what seemed to be a stubborn spot (I know, sketchy). Then I clean it again with a normal swab and take another picture.   This went on and on and I have basically ran out of swabs. I still see spots. I used the same swab a few times (I know, also sketchy) because I just couldn't figure out why it wasn't getting clean. I even tried a can of air (although some don't recommend that because they have solvent in them, but I was desperate and some people on youtube did it). That actually seemed to help, but in the end I still have spots.  So obviously a lot of you will tell me to just "take it in! you're going to break your sensor", but I really want to learn how to do this. And now I am just stubborn.  The spots are at the top and bottom of the frame mostly.  Any ideas? I ordered  today, and I was going to try it out very carefully. I also ordered .       EDIT: I tried the gel stick. It did seem to help, but on the second try something else got on the sensor so I am going to wait until tomorrow to get the swabs and then try to do a swab cleaning + the gel stick again... we will see.  EDIT2: Well it looks . I think the gel sticky stick helped but it's still not spotless. I ran over it one more time. I also included a photo above to the people are nervous about cleaning their own sensor. Obviously I can't guarantee you won't screw up, but I ran a swab over this sensor at least 15 times and it still shots great.


I was reorganizing my desks and found two different triple-ended USB cables. I don't know their origin or purpose. I have never seen triple-ended USB cables before. What are they used for?


What is the correct way to have a \thanks command for a specific author ?  I don't want to use \author{auth1 \and auth2} for obvious reasons (i.e. be able to distinguish the authors).  I have tried various options without success. Here is a rather minimal example where the two thanks are not attributed.  \documentclass{amsart}  \begin{document}  \title[short title]{Longtitle}  \author[Auth1]{Surn1 Auth1}  \author[Auth2]{Surn2 Auth2}  \address[Auth1]{adr1} \email{auth1@adr.org} \thanks{Network1}   \address[Auth2]{adr2}  \email{auth2@adr.org} \thanks{Network2}    \maketitle  \end{document}


I want to use memory mapping files for data that I read only once. Currently I am using: FILE * f = fopen("data.dat", "rb");  fseek(f, 0L, SEEK_END); size_t fileSize = ftell(f); fseek(f, 0L, SEEK_SET);  char * buffer = new char[fileSize]; fread(buffer, sizeof(char), fileSize, f); fclose(f);  //operate with buffer for (size_t i = 0; i < fileSize; i++){    //... }  I wanted to use mmap and operate directly on mapped buffer. However, I have found in Apple doc about mmap that there is:  You should not use file mapping in the following situations:  You want to read a file sequentially from start to finish only once.   Why? If I use fread there is more "logic", plus I am creating new array, that is also not for free.


Plural or singular when stating that an amount is enough

A colleague of mine corrected the following sentence in a text I had written:  A handful of  iterations was generally enough for convergence.  According to her it should be:  A handful of  iterations were generally enough for convergence.  I am, however, confident that my original usage was correct, but I am unsure how I should motivate this.  EDIT: What made me think it was singular was not "a handful of". I thought it would be correct to say Five iterations is enough. because it is a statement about the number of iterations rather than the iterations themselves. When googling to find an answer I found a television series called Eight Is Enough. Is that correct because the noun is left out? Compare the sentences: Three friends are ideal. and Three friends is ideal. I would have thought that the first sentence means that there are three persons who are ideal friends, while the second sentence means that three is the ideal number of friends to have. But maybe my intuition is really off here.  EDIT2:  it is stated that:     *Subjects expressing periods of time, amounts of money, or quantities may take either singular or plural verbs depending on whether represent a total amount or a number of individual units. For example, "Four weeks is not enough vacation time" and "Two days have passed since I asked for your response."   Isn't the first example here quite similar to mine?


Is there an explicit formula that gives the value of $\sqrt{2+\sqrt{2+\sqrt{2+\cdots}}}$ for $n$ square roots?

$$\sqrt{2+\sqrt{2+\sqrt{2+\cdots}}}$$  I know that with infinite square roots it's $x = \sqrt{2 + x}$, but what about a non-infinite number of roots? I've searched around a lot for this, and can't find anything useful, nor can I make a dent in the problem myself.   Maybe I'm searching using the wrong vocabulary?


Programmatically get own phone number in iOS

Is there any way to get own phone number by standard APIs from iPhone SDK?


what is $e$ really? what is its meaning?

I don't get it how we came up with $e$ and how can nature use this number so much! that is what I have been told and I only know that $e$ is a specific constant like $\pi$! I understand that $\pi$ just happens to be the ratio of circumference over diameter and I can accept that this is constant for any circle, but what about $e$? what is the real meaning of $e$? thanks!


How do I change the default session I get when I log in? I'm on Debian jessie. I tried changing settings on gdm3, tried installing lightdm and following  but it's just not working.  For more specificity, I'm trying to default to gnome-classic instead of gnome. I want to turn on the computer, log in as any arbitrary user, and see gnome-classic, not gnome3 (preferably I'd remove the gnome3 default session, if there's a way to do that).


How to get "subsubsections" in the table of contents if the document class is book?

I want to use the book class for a thesis and need to provide the table of content with chapter-section-subsection-subsubsection, all four should be displayed.   Is there any trick to make it, as I only get chapter-section-subsection if I use the normal \tableofcontents?


How to get name of calling function/method in PHP?

I am aware of function debug_backtrace, but I am looking for some ready to use implementation of function like GetCallingMethodName()? It would be perfect if it gave method's class too (if it is indeed a method).


I have a problem in C in Keil which is below this is sample C code.  struct A {     uint8_t header;     uint16_t volume;     uint16_t temp;     uint8_t footer; };   union {     struct A Packet;     uint8_t buff[6]; } A_union;   The problem is I want to fill struct with a header,footer and data and serialize it with buff but union changes byte offset (I cant even see footer in buff)as you can see in the picture. how can I solve it?  Update: as Sander suggested in  I solved the problem by modifying struct as below      struct __attribute__((__packed__)) A{ ...}


"System Memory" taking up too much storage

I have been facing this problem recently, my Samsung S 10+ has the storage information as shown in the image below. I don't know why the system memory is taking up 20 GB of storage. I cannot access it as well. On clicking it nothing happens. Would really appreciate help.


Prove by induction that for $n\geq1$, $(a_1+a_2+...+a_n)/n \geq (a_1*a_2*...*a_n)^{1/n}$

Prove by induction that for $n\geq1$, $(a_1+a_2+...+a_n)/n \geq (a_1*a_2*...*a_n)^{1/n}.$ I proved the base case, not sure how to do the inductive step. The values of the sequence are greater than or equal to zero.


I didn't see him go there/I didn't see him going there

Does the verb see accept an embedded clause with a bare infinitive verb like help or make(in the active voice)?


Singular or plural verb after "my experience in X, along with Y,..."

Singular or plural?  Would it be "make" or "makes" in this case:     I believe my experience in program management and evaluation, along with my Master’s degree in Sociology with a specialization in migration, makes/make me an ideal candidate for this position.


Weird display on screen before swipe lock Samsung Galaxy s6 edge plus

Pressed the onscreen button on my s6 edge this afternoon and a strange new display swipe screen is showing up - picture included. I have no idea where this came from and I have to swipe it just to get to my pin lock. I've checked my apps, my settings, my locked screen, I've disabled some of the apps I thought it could've been but to no avail. Does this look familiar to anyone, and if so how do I get rid of it? It's eating up my battery life.


Python - Shuffle an int list in each possible variant

I'm very new at python and maybe this is a possible duplicate, but I didn't found anything near these topic.  I want to shuffle an int list in each possible variant in python.  Example:  a = [2, 5, 8, 9]   Expected result:  variants =  [   [2, 5, 8, 9],   [2, 5, 9, 8],   [2, 9, 5, 8],   [2, 9, 8, 5],   [2, 8, 9, 5],   [2, 8, 5, 9],   [5, 2, 8, 9],   ... ]   Anyone an idea, to do this very fast and efficent?   Thanks for helping me guys.


I think this should be added to the faq and/or on the /ask page:  Advice to stick around for about 15 minutes after posting. Often this is the time when the fate of a question (or answer) is decided (at least on SO). Close votes are cast, obviously missing information is asked for and improvements are suggested. It's quite an annoyance to look at a 1 minute old question, spend 2 minutes reading it and finding out that a trivial detail is missing for me to be able to provide an answer, commenting about it and then receiving an answer in 2 days when I completely forgot what was the question about.  I think that newbies simply don't expect SO to react so quickly to their questions and don't refresh the page after a couple of minutes. It might be a good idea to suggest doing so.