Why can't I see all the significant digits when displaying vector?
How do I print a double value with full precision using cout?
Show that if $f:X\to Y$ is a continuous function if and only if the graph of $f$ is a closed subset of $X\times Y$ How long can eggs be unrefrigerated before becoming unsafe to eat? Searching by user id in Android app only shows questions, no answers I have a Samsung Galaxy S3. Android version 4.3  I downloaded the official StackExchange app today. I am not able to view post related to android tag from my profile. I tried refreshing also  Snap     Edit:  However i am able to see one post for the relevant from the drop down list    Edit 2:  I tried what Steven V suggested. However it's the same.    I tried for a different user its the same. Disfigured Feynman Diagrams! If $A$ is a square matrix and $A^2 = 0$ then $A=0$. Is this true? If not, provide a counter-example. This is a proof question and I am not sure how to prove it. It is obviously true if you start with $A = 0$ and square it.   I was thinking:  If $ A^2 = 0 $  then $ A A = 0 $  $ A A A^{-1} = 0 A^{-1}$  $I\,A = 0 $   but the zero matrix is not invertible and that it was not among the given conditions.  Where's a good place to start? Why does observation collapse the wave function? In one of the first lectures on QM we are always taught about Young's experiment and how particles behave either as waves or as particles depending on whether or not they are being observed. I want to know what about observation causes this change? Multiple Inheritance in C# Since multiple inheritance is bad (it makes the source more complicated) C# does not provide such a pattern directly. But sometimes it would be helpful to have this ability. For instance I'm able to implement the missing multiple inheritance pattern using interfaces and three classes like that: public interface IFirst { void FirstMethod(); } public interface ISecond { void SecondMethod(); }  public class First:IFirst  {      public void FirstMethod() { Console.WriteLine(&quot;First&quot;); }  }  public class Second:ISecond  {      public void SecondMethod() { Console.WriteLine(&quot;Second&quot;); }  }  public class FirstAndSecond: IFirst, ISecond {     First first = new First();     Second second = new Second();     public void FirstMethod() { first.FirstMethod(); }     public void SecondMethod() { second.SecondMethod(); } }  Every time I add a method to one of the interfaces I need to change the class FirstAndSecond as well. Is there a way to inject multiple existing classes into one new class like it is possible in C++? Maybe there is a solution using some kind of code generation? Or it may look like this (imaginary c# syntax): public class FirstAndSecond: IFirst from First, ISecond from Second { }  So that there won't be a need to update the class FirstAndSecond when I modify one of the interfaces.  EDIT Maybe it would be better to consider a practical example: You have an existing class (e.g. a text based TCP client based on ITextTcpClient) which you do already use at different locations inside your project.  Now you feel the need to create a component of your class to be easy accessible for windows forms developers. As far as I know you currently have two ways to do this:  Write a new class that is inherited from components and implements the interface of the TextTcpClient class using an instance of the class itself as shown with FirstAndSecond.  Write a new class that inherits from TextTcpClient and somehow implements IComponent (haven't actually tried this yet).   In both cases you need to do work per method and not per class. Since you know that we will need all the methods of TextTcpClient and Component it would be the easiest solution to just combine those two into one class. To avoid conflicts this may be done by code generation where the result could be altered afterwards but typing this by hand is a pure pain in the ass. I am a Physics undergrad, and just started studying Topology. How do you define neighborhood and open set in Topology.Wikipedia gives a circular definition.   An  is defined as follows.      In topology, a set  is called an open set if it is a neighborhood of every point    While a  is defined as follows:     If $X$ is a topological space and $p$ is a point in $X$, a neighbourhood of $p$ is a subset $V$ of $X$, which includes an open set $U$ containing $p$   which itself contains the term open set.  How do you define it exactly? Should "each" be followed by a singular or plural possessive? If a possessive noun, which is plural, is preceded by "each", then should it use the singular or plural possessive form?  For example, which of the following is correct?    spend time in each other's presence spend time in each others' presence How do I run Python code as a script? Related questions with over 99 score display incorrectly The score for the 4 questions are 111, 1218, 261 and 5 respectively, but they display 2 digits per line. This is an obvious bug in design. How to change boot priority? Cropping the exact same part of several pictures I have several pictures that are exactly the same except for some small variations. It was one picture that was photoshopped in several different ways. Now, I need to crop them all (13 in total) but I need to crop exactly the same part of it. It needs to be pixel perfect.  How do I do that with Pixelmator? Show that $\frac{1}{x_1^2}+\frac{1}{4\cdot x_2^2}+\ldots+\frac{1}{n^2\cdot x_n^2}\leq\frac{3n-2}{2n-1}$. Let $$x_n=\frac{1}{1^2}+\frac{1}{2^2}+\ldots+\frac{1}{n^2},\;\forall n\geq 1.$$ Show that $$\frac{1}{x_1^2}+\frac{1}{4\cdot x_2^2}+\ldots+\frac{1}{n^2\cdot x_n^2}\leq \frac{3n-2}{2n-1}.$$   I tried to prove it by induction  but I got a contradiction. Identify $E(X\mid X+Y)$ for $X$ and $Y$ independent and Poisson I am currently trying to understand how does an instance of the EM algorithm is derived when there are "hidden variables" in this old paper: .  I don't really understand how the expectation step is derived, and what bothers me the most, is that I cannot prove the following statement (right before 2.11):  $$ \mathbb{E}[X|X+Y] = \frac{(X+Y)\lambda_X}{\lambda_X+\lambda_Y} $$  where $X \sim Poisson\{\lambda_X\}$ and $Y \sim Poisson\{\lambda_Y\}$  To begin, I wrote the discrete expectation as follows: $$ \mathbb{E}[X|X+Y] = \sum_{k=1}^{X+Y} k P(X=k|X+Y)\\ = \sum_{k=0}^{X+Y} k \frac{P(X+Y|X=k)P(x)}{P(X+Y)} $$  Where I can replace $$ P(X+Y=k) = \frac{(\lambda_X+\lambda_Y)^ke^{-(\lambda_X+\lambda_Y)}}{k!}$$ $$ P(k=x) = \frac{\lambda_X^xe^{-\lambda_X}}{x!}$$ $$ P(X+Y=k|x) = P(Y=x-k) = \frac{\lambda_Y^{x-k}e^{-\lambda_Y}}{(x-k)!}$$  but I dont really know how to mix that together, because I don't really see what does the event $X+Y$ stands for, and how does it rely on the x in the integral ?  Thank you very much for you help Why is Euler's Totient function always even? The general consensus is that the single best indicator of a fund's future performance is the its expense ratio . If you look for more than 5 minutes online you discover the  approach to investing; the , etc. It looks like the less you pay for a fund (and therefore the less it's managed), the better it does in the long run.  So why is it that in peoples' 401(k)s there are so many high-cost actively managed funds? Furthermore, why are there so many high-cost actively managed funds in the first place? Shouldn't the market reflect the fact that actively-managed funds typically don't beat the index they benchmark to and and react by purging itself of these crappy funds? What are the most important things I need to do to encourage Google Sitelinks? Including pdf_tex images from inkscape I've recently installed Fedora 19.  is installed. But its own examples don't work. When I enter gedti the output is:  bash: gedti: command not found... Similar command is: 'gedit'   And it works correctly but when I enter powertop, the output is:  bash: powertop: command not found...   With no suggestion about the package. Why? Should I edit some configuration files or update some cache or ... ?