Callback executing before function
How do I return the response from an asynchronous call?
Is “all women who are mothers of daughters” right? Is the expression      All women who are mothers of daughters are here.   correct? I mean every woman who has at least one daughter is here. Mod of numbers with large exponents [modular order reduction] Can photons be detected without being absorbed? I am thinking about a detector that would beep if light passes through it. Is it possible? Discontinuous derivative. Could someone give an example of a ‘very’ discontinuous derivative? I myself can only come up with examples where the derivative is discontinuous at only one point. I am assuming the function is real-valued and defined on a bounded interval. Setting up virtual host Maven artifact and groupId naming Some websites and textbooks refer to $$\Delta x \Delta p \geq \frac{\hbar}{2}$$ as the correct formula for the uncertainty principle whereas other sources use the formula $$\Delta x \Delta p \geq \hbar.$$ Question: Which one is correct and why?  The latter is used in the textbook "Physics II for Dummies" (German edition) for several examples and the author also derives that formula so I assume that this is not a typing error.  This is the mentioned derivation:     $\sin \theta = \frac{\lambda}{\Delta y}$      assuming $\theta$ is small:      $\tan \theta = \frac{\lambda}{\Delta y}$      de Broglie equation:      $\lambda = \frac{h}{p_x}$      $\Rightarrow \tan \theta \approx \frac{h}{p_x \cdot \Delta y}$      but also:      $\tan \theta = \frac{\Delta p_y}{p_x}$      equalize $\tan \theta$:      $\frac{h}{p_x \cdot \Delta y} \approx \frac{\Delta p_y}{p_x}$      $\Rightarrow \frac{h}{\Delta y} \approx \Delta p_y \Rightarrow \Delta p_y \Delta y \approx h$      $\Rightarrow \Delta p_y \Delta y \geq \frac{h}{2 \pi}$      $\Rightarrow \Delta p \Delta x \geq \frac{h}{2 \pi}$   So: Which one is correct and why? Page returns 404 with POST variables, but not without I have a problem with my page. I'm trying to make a "Contact Us" page. It's working perfectly fine design-wise. But when I try to send the form to the same page as origin. It returns 404 error.  It only happens when I'm sending the form. I've tried both with GET and POST requests. Nothing seems to work.  I've even commented out the PHPMailer part. It's caused entirely by the extra variables.  If it helps anything, they're "name", "email" and "message". Showing $d(x,y) = \frac{|x-y|}{1+|x-y|}$ is a distance. Show that $(\mathbb{N}, d)$ is a metric space   with $$d(x,y) = \frac{|x-y|}{1+|x-y|}$$   My attempt:   let $x,y \in \mathbb{N}$,  1) $d(x,y) = 0 \implies |x-y| = 0 \iff x = y$  2) $d(x,y) = d(y,x)$  3) show for $z \in \mathbb{N}$, $d(x,z) \leq d(x,y) + d(y,z)$  Using the triangle ineuqality I managed to get:  $$d(x,z) \leq \frac{|x-y|}{1+|x-y| - |y-z|} + \frac{|y - z|}{1 + |x-y| - |y-z|}$$  but i assume here I must use the fact that $x,y,z \in \mathbb{N}$ but I'm not sure how.  Any hints please:  edit: improvements on solution - Using fact that $|x-y|$ is a metric we have that $$d(x,y) \leq \frac{|x-y|}{1+|x-y| + |y-z|} + \frac{|y - z|}{1 + |x-y| + |y-z|}$$ (Since $|x-z| \leq |x-y| + |y-z|$) Is this correct? From there I can use the fact that $$\frac{1}{1+|x-y|+|y-z|} \leq \frac{1}{1+|x-y|} $$ and $$\frac{1}{1+|x-y|+|y-z|} \leq \frac{1}{1+|y-z|}$$ to conclude? Show that there is a positive integer $n$ such that $G \cong \ker(\phi^{n}) \times \phi^{n}(G)$ Let $G$ be a finite abelian group and let $\phi: G \rightarrow G$ be a group homomorphism. I am trying to show that there is a positive integer $n$ such that $G \cong \ker(\phi^{n}) \times \phi^{n}(G)$.  I know that since $G$ is abelian we have that $\ker(\phi^{k})$ and $\phi^{k}(G)$ are normal subgroups of $G$ for any $k$  I also suspect we have the following towers which stabilize at $m$ and $m'$  $$\phi(G) \unrhd \phi^{2}(G) \unrhd \cdots \unrhd \phi^{m}(G)=\phi^{m+1}(G)=\cdots$$  $$\ker(\phi) \unlhd \ker^{2}(\phi) \unlhd \cdots \unlhd \ker^{m'}(\phi)=\ker^{m'+1}(\phi)=\cdots$$  I know that if given a group of the form $HK$ where $H$ and $K$ are normal subgroups of $HK$ and $H\cap K=1$ then $H \times K \cong HK$. I want to apply this to this situation but I am unable to show how write $G$ as a product $HK$  Resolution One of the comments directed me to the following article:  The last part of which answers the question. Below is what is says:  Choose $n=\max(m,m')$, then we have for $x \in \ker^{n}(\phi) \cap \phi^{n}(x)$, this means that $x=\phi^{n}(y)$ for some $y \in G$. This gives:  $0=\phi^{n}(x)=\phi^{2n}(y)$ which means that $y \in \ker^{2n}\phi=\ker^{n}{\phi}$. and then we have that $0=x=\phi^{n}(y)$.  The answer below kindly points out that every element $x$ is contained in one of the cosets of $G/\ker^{n}(\phi)$, this means that $x=k+g$ for some $k \in \ker^{n}(\phi)$ and $g \in G$. We also have that $g=\phi^{n}(h)$ for some $h \in G$. Writing $x=k+\phi^{n}(h)$ essentially shows that $G=\ker(\phi^{n}) + \phi^{n}(G)$. Using the fact above, the claim follows. Is it possible to unwrap materials made in Vertex Paint? I painted an group of objects in Blender using the Vertex Paint and was wondering if it would be possible to unwrap the mutliple materials(when the objects are joined together using Ctrl+J)? Do I have to paint it all over again? When upgrading to Ubuntu 14.04 from Ubuntu 12.04 I am getting the following error:     W:Failed to fetch    Unable to find expected entry 'non-free/source/Sources' in Release   file (Wrong sources.list entry or malformed file) , E:Some index files   failed to download. They have been ignored, or old ones used instead. Open an app on startup/after booting I need to force a selected application to start up each time my Android-based device is (re)started.  Is there anything I can use (configuration setting, external application etc.) to accomplish this task? Or is this kind of behavior limited to home screen managers only? Lost passport with Schengen visa Trigger a php file on every post or page if a condition is met I was wondering if we can trigger a PHP file on every WordPress post or page if a certain condition is met. Let me detail what I want.   Can we write a simple PHP script that will be automatically loaded on every WP post and page. Once loaded, the script should scan the HTML and if it finds a specific DIV tag with the ID myID it should trigger another PHP file (let's say script.php). Once the target PHP file has been triggered or executed, the target PHP file (script.php) should be able to automatically fetch the URL of the post or page that triggered the file and store it in a variable.   Any ideas?? Sum over multiple indices Is there a dominant gene for right-handedness? Has there been any definitive research about handedness being genetic? Also, why is right-handedness clearly dominant in humans? I'm interested in evolutionary theories, as well as any molecular explanation (if known). What makes Stealing Signs wrong? Migrate database from Postgres to MySQL Why some dragon claw doors do not open?