Do not show ellipsis when not needed in search results

When doing a search, the results page shows an ellipsis when it is not needed. For instance:    The message of that answer is shorter than the text overflow limit, which means the ellipsis (...) should not be shown.


removeAttribute removes all other classes associated with element

I am trying to use removeAttribute() to remove one specific class attribute from an element. The problem is that removeAttribute() seems to remove all of the other defined class attributes on the element.  Example:  HTML  Click

   CSS  .blue {   background-color: blue; }  .dotted {   border: thin dotted grey; }  .width-50 {   width: 50px;   height: 50px; }   JS  var el = document.getElementById('click'); el.addEventListener("click", removeColor, false);   function removeColor() {     var box = document.getElementById('box');     box.removeAttribute('class', 'blue'); }   How can I just remove the one class attribute from the element, without affecting the other class attributes on the element?


Why won't OS X trust GitHub's SSL certificate?

When I go to any github.com page in Chrome, I get a big ugly error:  You attempted to reach github.com, but the server presented a certificate issued by an entity that is not trusted by your computer's operating system. This may mean that the server has generated its own security credentials, which Chrome cannot rely on for identity information, or an attacker may be trying to intercept your communications. You cannot proceed because the website operator has requested heightened security for this domain.  The same thing happens (in Chrome and with curl) when I go to  too. This strange problem started about a week and a half ago. Here's what I see when I click the broken lock icon in the address bar:   But gist.github.com works just fine:   It doesn't work with curl either:  Everything works fine in Firefox. How can I fix my root CA problem? Here's what it looks like in Firefox:   Update: I noticed that the first certificate in the chain is different in my broken Chrome/Safari as compared to Chrome on my other computer.   (There's no nasty red X anymore because I trusted it in Safari.) See how the issuers are different? What can I make of that?


Finding the creation/annihilation operators

Using Minkowski signature $(+,-,-,-)$, for the Lagrangian density   $${\cal L}=\partial_{\mu}\phi\partial^{\mu}\phi^{\dagger}-m^2\phi \phi^{\dagger}$$  of the complex scalar field, we have the field  $$\phi(x)=\int{\frac{d^3 \vec{p}}{2(2\pi)^3\omega_\vec{p}}}(a(\vec{p})e^{-ipx}+b^{\dagger}(\vec{p})e^{+ipx}).$$  I'm trying to now find an equation for the $a(\vec{p})$ and $b(\vec{p})$ (with the final goal of finding an expression for $[a(\vec{p}),b^{\dagger}(\vec{q})]$ using $[\phi(x),\Pi(y)]$).   What I should note is that we are considering all of this in the Schrodinger picture (t=0) so I suppose the very first thing to do is change all the $x$'s to $\vec{x}$ right?  The strategy I'm struggling to implement and failing at many points along the way:   Find the momentum $\Pi^{\phi}(x)=\frac{\partial L}{\partial \dot{\phi}}=\dot{\phi^{\dagger}}$. Add some combination of $\phi(x)$ and $\Pi(x)$ to get rid of one of the creation/annihilation operators.  Do an inverse Fourier transform to find $a(\vec{p})$ in terms of $\phi(x)$, for example.    None of the major text books seem to actually carry this through, and instead write something like "and it's easy to show…". However I don't find it too easy, especially part 3. as I'm not a Fourier transform expert.   Could anyone either direct me somewhere where the above is computed explicitly (in more than 2/3 lines), or help me understand each of the 3 steps above?  (I realise it is easy to find a reference where this is done for the real scalar field, in which case we have $a(\vec{p})$ and $a^{\dagger}(\vec{p})$. Even still, I find it hard to follow parts.)


Is it true that $|a-b|<t \Longrightarrow |a|<|b|+t$

Let $a$,$b \in \mathbb{R}$ be two real numbers and let $t \in \mathbb{R}_+$ a real positive number.  I would like to know if is it true that  $$ |a-b|<t \Longrightarrow |a|<|b|+t $$  Thanks.


Preventing SQL Injection in dynamical SQL

I am forced to generate dynamic SQL.  I realize it greatly complicates matters to do so, and the below example is silly and obviously does not require dynamic SQL, and is just used to illustrate this question.  Escaping user provided data is not enough, and the 3rd query in the below script is suspect to SQL Injection.  I have found that it is generally easiest to design the application so that all user inputs are integers, and simply typecast their input using (int)$_POST['user_input'].  I now have a need where the user_input needs to be text.  What should I do to prevent SQL injection?  One option is PHP's ctype_alpha(), however, I don't want "user,input" to result as FALSE, but should either remain as is or be converted to "userinput" (either scenerio is okay for me).  I am thinking of something like $user_input= preg_replace('/[^a-z0-9,]/i', '', $_POST['user_input']);.  Will this be 100% safe?  EDIT  Note that I am not executing the below query, but inserting it into a database, and as such, prepared statements are not appliable.  You might believe that dynamic SQL generation should never be used, but telling me to use prepared statements is not right.  <?php $id=123; $query='SELECT * FROM someTable WHERE someColumn="'.$_POST['user_input'].'"'; $sql='INSERT INTO meta_table (id,sql) VALUES (?,?)'; $stmt=db::db()->prepare($sql); $stmt->execute(array($id,$query));  $sql='SELECT sql FROM meta_table WHERE id=123'; $stmt = db::db()->exec($sql); $query=$stmt->fetchColumn();  $stmt = db::db()->exec($query); //Prone to SQL Injection $rs=$stmt->fetchColumn(); ?>


My MacBook Pro kernel-panicked with this message, "You need to restart your computer. Hold down the power button until it turns off, then press the power button again."  The same message appears each time I reboot.


How can I upgrade my wildfire s to jellybean? Help anyone? What are the risks? I tried to look up on google but couldn't find anything usefull..HELP!


GeoServer raster tiles are individually contrast-balanced: how to turn this off?

I'm running GeoServer locally as a servlet (in JBoss), and I'm serving a GeoTIFF file through the WMS protocol.  In a webpage running an OpenLayers map, I have the GeoTIFF-WMS layer overlaid above an OpenStreetMaps base layer.  The problem is that it looks like this:    The GeoTIFF is clearly being tiled (good) and each tile is normalized to a given brightness level (bad).  When I zoom in, I can see a similar effect taking place on the smaller tiles, and I know that the original GeoTIFF doesn't have this blockiness: it's a diagonal strip of 16-bit greyscale surrounded by zeros that ought to be transparent.  How do I turn off this brightness-normalization feature (or what is it called, so that I can Google it)?  Even better, how do I tell GeoServer that pixels with zero values ought to be transparent?


I was just reading the responses to a question as to why RAW images look different in lightable and darkroom in Darktable (due to the in camera post processing taking place for JPG files) and I would like to know a little more about this conversion process. I thought the camera only compresses the image when it converts the RAW file to a JPG? But the process also involves manipulating the tones of the image using some algorithm whether I like it or not. Why does it do this? It looks better than the RAW file, why doesn't the RAW file look as good?  Thanks, TheCube


I have been talking to a chick that says she needs 4500 euro in her bank account in order to obtain a 90 day tourist visa to visit Ireland.


How to say that food is hot (temperature) without the listener thinking that I mean "spicy"?

There is an excellent discussion of spicy vs. hot here:   However, having read the previous question, I did not see any answer that tells how to say unambiguously that food is hot (temperature) without being misunderstood.  If I say that my food is spicy, a listener will unambiguously understand that I am referring to the sensation associated with eating.  However, I can't think of a good way to say that my food is hot (temperature) without a listener possibly thinking that I mean spicy.  In the referenced question, a poster described how to unambiguously say that food is spicy.  How can I unambiguously say that food is hot?


Closely spaced nonoverlapping 36 (2x12x2) gears borrowing from music theory. Good idea?

I had an idea.  Why not space gears on a bike the same as musical notes?  For example, in music, if you start on a certain note (let's say C3), you need to go up 12 more half steps (notes) to get to C4, an octave above C3.  The frequency of C4 vs. C3 is exactly double.  The notes are spaced with intervals of 2 ^ (1/12) which is about 1.06. So for a 12 speed bike, you would have 12 closely spaced gears which you could shift individually if you need close ratio or in pairs if you want more normal 12% spacing.  When you run thru all those gears you could then flick a doubler gear (maybe located in the bottom bracket) that then doubles all the ratios and then you repeat all of those 12 gears again in order.  There would also be a doubler gear in the hub.  So for example, in the low mode, you can have gears 0.50 to 0.94  Engage one doubler (either one) and you get 1.00 to 1.92, engage both doublers and you get 2.00 to 3.84.  Notice there is no overlap in the gears.  you will basically have a progressive 36 speed with the option to shift 2 gears at a time (skipping gears) if you want 12% between gears and thus making it a progressive 18 speed.  More likely is you would pick a range (low, med, or high) and use it as a close ratio 12 speed.  You could even use it as a super wide range (4:1) 3 speed.  Just pick a middle cog for example with the halving gear enabled, spin that out then disable it, thus doubling your gear.  After spinning that out actuate the doubler gear and you can go fast.  You can control the overall range by changing the single front sprocket.  For example, 36T could start you out at 0.50 in the low gear but maxes out at 3.84.  If you prefer taller you could run a 45T so you start out at 0.625:1 and top out at 5.00:1. (135 gear inches on a 27" diameter tire).  Also since the gear changes between the 3 ranges are from one end of the shifter (12) to the other (1), you can just twist the shifter quickly, eliminating the need for a precision shift like in a 3x9 progressive shift attempt where you have to "bounce" between chainrings and cogs.  So here is my 1st attempt at getting close to 6% between gears using cogs:  36, 34, 32, 30, 29, 27, 25, 24, 23, 21, 20, 19.  I know for me, I would spend a lot of time in the middle range (1.00 to 1.92) and would love to have the close ratios for when I get a headwind.  What sometimes happens is I would shift from a 16T cog to an 18T but what I really needed is a 17T.  Well my new gearing system would handle that cuz you can shift from a 32T to 34T which is same as going from 16T to 17T as far as gear ratio.  So is this a good enough idea for someone to build this bike?  What would be the drawbacks of it?  Might the efficiency go down significantly with the triple gear setup or should it be ok?  Note that on motorcycles, only about 85% of the power of the engine makes it to the rear wheel so I would think if a bike is 85% or better that is acceptable with 90+% being a target.  Correction:  one will be a halving gear and the other would be a doubling gear.  With both disabled (bypassed), the bike would be in the midrange gears (1.00 to 1.92 for example).  Front sprocket would be size 36T to get midrange to start out at 1.00 (36/36) but of course roadies can adjust larger such as 45T and mountain bikers can adjust lower such as 32T or even 30T.  Extreme hill climbers that want a 7.5" gear (27" diameter tires) would need a 0.278:1 low gear which can be had by replacing the 36T front sprocket with a 20T.  Even with that ultra low first gear, shifting to the highest gear would give about 60 gear inches which is good enough for cruising around.


She is the one whom I love the most.   During an English lesson, this sentence came up and my answer was whom. My teacher told me that it is not the best answer (that is who), it is kind of awkward and she would not use it should she say something like this.  Could anybody comment on the use of whom in Modern English and how acceptable it is?  Is there any case when whom cannot be replaced with who, either stylistically or grammatically?


This is old news ...but I am having trouble understanding why some of Alanis Morisette's examples from her song 'Ironic' are not ironic.  For example: "An old man turned ninety-eight.  He won the lottery and died the next day."  In this case, isn't there an incongruity between what he expected and what happened? He was hoping to win the lottery his whole life...but when he finally did, he ended up dying. Isn't there an outcome in this case that was opposite to what was expected?  Another example: "It's meeting the man of my dreams and then meeting his beautiful wife."  Isn't this ironic because she tries hard to find the right guy but then finds him and that he is married. Isn't his married status opposite to what was expected?  Thank you for answering these questions.


Let $a,b$ be . Is there an efficient algorithm to calculate $a*b$, the nim-product of $a$ and $b$?  The following rule seems like it could be helpful:  $$ 2^{2^m} * 2^{2^n} = \begin{cases} 2^{2^m} 2^{2^n} & \text{if $m \ne n$} \\ 3(2^{2^m - 1}) & \text{if $m = n$} \\ \end{cases}. $$  Juxtaposition denotes ordinary ordinal multiplication here (not nim-multiplication).


How to create another partition on my pc

I want to create another partition in my pc, I shrink the primary partition :E and created a new logical dive :D , But when try same for the :C , I get error that I already have maximum number of partitions.  Here are screenshots to explain this    You can see the logical drive I created earlier, If you look at it it shows another unnamed partition too, I DO NOT KNOW WHERE IT IS , Then I tried to shrink :C and create another logical drive but I get this error.    Now my question is HOW CAN I CREATE ANOTHER PARTITION OR IF IT IS NOT POSSIBLE IS THERE ANY WAY I CAN ADD THIS SHRINKED SPACE TO :D or :E ?  I tried my self but there is no such option . I am using win7, core i5 laptop, toshiba .


Here's a module with castellated pads attached to an eval board:  (source: ) Looking closely at the wires interfacing with the castellated pads, they're clearly soldered to the eval board. However, they don't look like they're soldered to the module, but rather they're being pressed against the pads with the tension in the wire. It also looks like the free end of the loops are protruding down into a channel cut in the PCB. Do these kind of connectors/metal loops have a name?


This might look funny but this is disturbing me for quite a while, that is,  why $$f'(z)=u_x+iv_x.$$ Why the partial derivatives $u_y$ and $v_y$ are being ignored? From the following limit: $$\label{1} f'(z)=\lim_{h\to0, \>h\in{\mathbb R}}{f(z+h)-f(z)\over h}={\partial f\over\partial x}(z)=u_x(x,y)+iv_x(x,y)\ ,\tag{1}$$   I can understand that the infinitesimal $h$ is real and this corresponds to increment in $x$ variable only, but why the variable $y$ is being ignored? If this is the case, then won't the limit \eqref{1} would only be defined in the horizontal neighborhood of $0$, without considering increments in vertical or any other direction in complex plane?


Why reject, not accept $H_0$ when $p$ value less than $\alpha$?

Let's say ABC drug company claims their medicine cures 90% of patients. Now a doctor conducts a trial by taking a random sample of 15 patients. Result shows 11 of them are cured but 4 are not.   In this case, $H_0$ should be: $p=0.9$. And $H_1$ is: $p<0.9$. If we use $X$ to represent the number of people cured in the sample, then $X \sim B(15,0.9)$.   If significance level ($\alpha$) is set as 5%, the critical region in this case should be defined as:     $P(X<11)<\alpha$ where $\alpha=5\%$   , $H_0$ will be rejected if the expression is true.   This really confuses me. The smaller of $P(X<11)$ is, the larger of $P(X>11)$ should be. Then the more patients should be cured and more likely H0 should be accepted. Anything wrong with this?    To me, it seems to make more sense if $P(X>11) < \alpha$  proves to be true to reject $H_0$.


Do you say "I like apple" or "I like apples"?

When stating a general fact/preference on countable nouns, singular or plural is more suitable and natural? Example 1 :  I like apple. or I like apples.  Example 2:  I like eating apple. or I like eating apples.


A pendulum with an hollow bob full of flowing sand

THE PROBLEM  Consider a pendulum with an hollow spheric bob of negligible weight filled with 1.1 kg of fine sand and hanging from an inextensible wire of negligible mass and $l= 30 m$ long. At the point which is diametrically opposite to the point where it is hung to the wire, the sphere has a small hole from which the sand can come out with a constant flow of 1 g/s.  In the rest position the hole is at a distance $h = 1 m$ from the horizontal floor. At time $t = 0$ the sphere is placed at a distance $d = 30 cm$ from its rest position, the hole is opened and the sphere is let go (see the drawing for a better understanding).  Neglecting any friction and referring to a Cartesian axis that runs along the floor in the direction of the motion of the sphere and whose origin is at the point closest to the rest position of the sphere, compute:   the position where the sand falls as a function of the time $t$; the maximum distance at which the sand is deposited; the points where the greatest amount of sand is accumulated; the distribution of the mass of sand on the floor.   Assume that the sand remains exactly at the point where it touches the floor.  HINT Some useful trigonometric formulas: $$cos(arctan(x))=\frac{1}{\sqrt{1+x^2}}\qquad\qquad \sin(arctan(x))=\frac{x}{\sqrt{1+x^2}}$$    (WORKING ON) THE SOLUTION  I suppose that the first thing to notice is that the little-angle approximation can be used since the starting angle $\vartheta_{\text{MAX}}$ (at $t=0$) is easily computed as $$\vartheta_{\text{MAX}}=arcsin(d/l)=arcsin(0.01)\simeq 0.01000017$$  and it's very small. Hence $sin(\vartheta)$ can be approximated with $\vartheta$ and $cos(\vartheta)$ with $1$.  In this approximation, it is well known that the pendulum period is $$T = 2\pi\sqrt{\frac{l^*}{g}}$$ Now, strictly speaking, $l^*$ should be the distance between the point in which the wire is hung and the center of mass of the bob. At $t=0$ this means $l^* = l+R$, where $R$ is the radius of the hollow sphere. With the sand flowing away, the center of mass will shift downwards, increasing $l^*$ and hence increasing the time period only to be back at its initial position $l+R$ when there's no sand left inside the bob.  However, since the problem does not give the value for $R$, I assumed that a point-like approximation for the bob could be used, hence using $l^* = l$ regardless of how much sand is left inside the sphere.  I guessed this is what who wrote the problem was asking for since the period so computed is $T \simeq 11s$: a number matching too well the $1.1 g/s$ of the constant flow of sand to be a coincidence (giving the sphere emptied in $100$ periods).  Assuming all of the above is right, I went on to write the equations of motion for the flowing sand:   \begin{array}{ll}         x(t) &= x_s + v_x t = l\,sin(\vartheta(t)) + l \dot{\vartheta(t)} t \simeq l\,\vartheta(t) + l \dot{\vartheta(t)} t\\         y(t) &= y_s + v_y t - \frac{g}{2}t^2= h + l(1-cos(\vartheta)) + l \dot{\vartheta(t)} sin(\vartheta(t)) t - \frac{g}{2}t^2 \simeq h + l \dot{\vartheta(t)} \vartheta(t) t - \frac{g}{2}t^2         \end{array}    Then I'd like to set $y(t)=0$ in order to solve for $t$ and substitute inside the equation for $x(t)$...but I don't know how to proceed. Plus, how should the given HINT be useful?  Any help to solve this would be extremely appreciated!  EDIT (why this is not a duplicate)  This question is not a duplicate because I'm not asking of how the period of pendulum varies with the flowing of the sand but, assuming it does not vary (an approximation), I'm asking about the position where the sand falls as a function of the time $t$; the maximum distance at which the sand is deposited; the points where the greatest amount of sand is accumulated; the distribution of the mass of sand on the floor.


$AB=BA$ and $A$ has $n$ eigenvalues. Prove $B$ is diagonalizable

Question:  A and B are matrices size $n\times n$  given $AB=BA$ and A has n eigenvalues, prove $B$ is diagonalizable.  I would have written what I tried to do, but It's really nothing worth reading..  Any help would appreciated,  Thanks.


Prove or disprove: If $H$ is normal in $G$ and $H$ and $G/H$ are abelian, then $G$ is abelian.

My counterexample I wanted to try is $D_{8}$ and its center $Z(D_{8})$. However, is $Z(D_{8})$ abelian? I am guessing it is because it is cyclic? I am not very knowledgeable with dihedral groups.


I'm on Windows 10. Android studio version 2.3.3   How can I launch the AVD Manager with-out opening the Android Studio and creating a project ?  I remember it was possible for earlier version of Android Studio. I found the avdmanager.bat file in Android\Sdk\tools\bin but running it won't launch the avdmanger UI that we get from the Android Studio.  Anyone here faced the same issue and found a way to launch AVD manager from command line ?


How to check the correlation between categorical and numeric independent variable in R?

Just wondering if i need to check correlation between categorical and numeric independent variable in R, is there any specific package available in R. Or should i just find the correlation between the numerical independent variable?


I have to change /proc/sys/kernel/yama/ptrace_scope value in order to use gdb attach. Whenever I change it with sudo nano or sudo gedit, it says: no permission or gives me an error and when I restart my PC it resets back to 2.


Restoring Partition Table and Files After Failed DISKPART Acrobatics

A friend of mine wanted to convert his MBR boot drive to GPT to use UEFI. He accessed DISKPART over the command prompt within the Windows installation environment using SHIFT + F10 and used clean then convert gpt on his disk. After that he proceeded with the setup partitioning his disk and installing the system. What methods can we try to restore the partition table and files?


Which one is correct:     Someone like me...   or     Someone like myself...   Is "like myself" ever correct?


how can you easily check if access is denied for a file in .NET?

Basically, I would like to check if I have rights to open the file before I actually try to open it; I do not want to use a try/catch for this check unless I have to. Is there a file access property I can check before hand?


Passing variable in function in Javascript

When you pass variables in Javascript functions, what is the difference between '$name' and 'name'.  For example,  var myFunction = function(name){   name.a = "a";  };  var myFunction = function($name){   $name.b = "b"; };


Ubuntu 20.04 installer stuck at “running dpkg”

I've got a HP probook 430 g4 with an 64x architecture. I deleted (accidentally) the OS that it had. I tried to install Ubuntu 20.04 Desktop with the “try Ubuntu” and something else way. The HDD was empty so I partitioned the disk into /boot (1Gb), / (10Gb), /home (970Gb), /var (12Gb) and swap area (2Gb). The installation goes well until the “running dpkg” part after “looking for other OS”. What could I do ? I've been four days doing what I read on internet and nothing works. Graphics: Intel graphics 620. I try with internet conection and without.


Many requests over port 445 on Ubuntu VPS, what could it mean?

I own a small VPS hosted by Hetzner on which i run a small Minecraft game server. The VPS is running on Ubuntu, and the only software i installed are Java JRE and the required software to run a Minecraft game server (+ additional plugins).  I ran a tcpdump over night and here is the result:   Could anyone help me read it?  Is it regular?  First of july i received a mail from abuse@hetzner.com (my host) stating that Columbia University sent them an automated notice regarding unwanted traffic coming from my ip address.  Here is the original Columbia University message:   But it also said:     It is possible that this alert is the result of a reflection attack against your network with a spoofed origin matching Columbia   University's network.   Details are provided below.  Please take all   necessary steps to mitigate such attacks, or ignore this notice if   this traffic is spoofed.   So could that be just a random occourrence? Or is my server hacked?


I have a problem with an app that i try to run. I have a listview which is made from names that i add in an edittext of a class. When there are no items, when i move to listview the app crashes and i get that error:  java.lang.NullPointerException: Attempt to invoke interface method int java.util.List.size() on a null object reference  While I have one or more items in listview I can see them without crashes or errors. Can you help me please? Below is my code.  public class ListAdapter extends BaseAdapter { Context context; List<Student> valueList;  public ListAdapter(List<Student> listValue, Context context) {     this.context = context;     this.valueList = listValue; }  @Override public int getCount() {     return this.valueList.size(); }  @Override public Object getItem(int position) {     return this.valueList.get(position); }  @Override public long getItemId(int position) {     return position; }  @Override public View getView(int position, View convertView, ViewGroup parent) {     ViewItem viewItem;     convertView = null;      if(convertView == null)     {          viewItem = new ViewItem();          LayoutInflater layoutInfiater = (LayoutInflater)this.context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);          convertView = layoutInfiater.inflate(R.layout.listviewitem, null);          viewItem.TextViewStudentName = (TextView)convertView.findViewById(R.id.textView1);          convertView.setTag(viewItem);      }     else     {         viewItem = (ViewItem) convertView.getTag();     }      viewItem.TextViewStudentName.setText(valueList.get(position).StudentName);       return convertView;}} class ViewItem{TextView TextViewStudentName;}   The error is located in command return this.valueList.size();. If you need i can post the other classes of my code too. Thank you in advance!


SAN Storage shared disk, files copied from other servers cannot be seen without re-mounting

I have a SAN Storage connected to my servers using fibre HBA. Using multipath, I've successfully mapped the device, formatted it as ext3, and mount it to my file system.  But the problem is, the host can't see the files other hosts copy to the shared disk without re-mounting the device.  I'm using CentOS 6.4


"Parsing filters unsupported" error during extraction of RAR file

I have received an .rar which I wish to unpack as it contains something rather important to me that I need to really have now. However even though I can view the contents of the .rar archive in the Archive Manager, I am unable to extract it due to this error:    The archive should contain two folders within it, each though contain at least 10 audio files as well as a PDF file each (I don't know what the contents exactly should be except for there should be audio files in there, and the content I have described is what I can see from the Archive Manager's view). So the only thing I am left with except the error is one of the folders and one of the audio files, but it says it has 0 bytes in it.  So how exactly do I fix this problem? I am running Ubuntu GNOME 16.04.1 with GNOME 3.20.  Information Update:  In reply to a comment requesting the output from the dpkg -l unrar unrar-free command:  Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name           Version      Architecture Description +++-==============-============-============-================================= un  unrar          <none>       <none>       (no description available) dpkg-query: no packages found matching unrar-free


Factorial Proof by Induction Question: $ \frac1{2!} + \frac2{3!} + \dots+ \frac{n}{(n+1)!} = 1 - \frac1{(n+1)!} $?

$\text{Use the PMI to prove the following for all natural numbers n.}$     $ \frac{1}{2!} + \frac{2}{3!} + \cdot \cdot \cdot + \frac{n}{(n+1)!} = 1 - \frac{1}{(n+1)!} $   So for this question I get stuck because I cannot seem to make the left side and right side be equivalent.    $\color{Green}{Proof} :$   $\mathbf (I) \; Basis \; Step :$  Show $p(1).$ For $n=1$  $\frac{1}{(1+1)!} = 1- \frac{1}{(1+1)!} \Rightarrow \frac12 = \frac12$  $\mathbf (II) \; Inductive \; Step : $   Assume $p(k)$ for a PAC $k \in ℕ ,\; \; \;\; n=k$  $ \frac{1}{2!} + \frac{2}{3!} +\cdot\cdot\cdot + \frac{k}{(k+1)!} = 1-\frac{1}{(k+1)!} \; \;  \text{Induction Hypothesis}$  Left Hand Side : We need to show : $p(k+1)$ i.e. $n = k+1$  $\frac{k}{(k+1)!} + \frac{k+1}{(k+1+1)!} \Rightarrow \ $  $\frac{(k+1)}{(k+1+1)!} +1 - \frac{1}{(k+1)!} $  Right Hand Side: $ n =k+1$   $\left(  1- \frac{1}{(k+1+1)!}\right) = 1- \frac{1}{(k+2)!}$  This is where I have made my mistake because I think I have made an arithmetic mistake on the left side because I cannot get them to be verifiable. Any hints on how to correct the  error would be appreciated. Have a good one.


Can I play on my Xbox one with someone else that is on a Xbox 360?

Am I able to play my Xbox one online and join my friends game who is playing on a Xbox 360? If so what games?


Resetting Debian Password without restarting at all?

My company has a Debian server that holds and runs some important stuff that cannot be shut down... The previous Joe before me, didn't seem to have a password logged or even passed on the information about it, so we're at a loss. Is there a way to recover/change/get into the computer files without resetting the server?


Somewhat related to ...  It appears the combined flair has space for about 7 Stack Exchange sites (I'm estimating, I've only got 4 on there now).The combined flair can fit 7 different Stack Exchange sites. What happens if a user has more than 200 rep on more sites than the seven sites that fit on the flair? Does the flair   Use what first went on and ignore anything beyond what fits? (Mine currently seems to be ordered based on how old the profiles are) Use the top-repped accounts, and order them by rep? (Mine may be doing this, but I can't tell at this time, since rep order and age order are the same) Break? Randomly select some sites?   Has anyone encountered this before, or is it unusualy to have 200+ rep on that many different Stack Exchange sites?


Minimum passport validity for travelling to Japan

I'm planning to travel to Japan and I just realised my passport will have less than six months validity at the time I travel.  I know some countries require at least 6 months validity for entry. Is this likely to be a problem for Japan?  (As an Australian citizen I don't require a visa for short term tourist entry)


When driving on a wet highway at night, any surface emitting or reflecting light will have a reflection right under it that is blurry and seems to stretch to infinity.  This is not exactly what I am picturing in my mind, but I couldn't find better images. Anyway, I think it'll do.    Does anybody know why it is such a long reflection? I never figured it out myself.


How do I access my software updater if it doesn't display anywhere?

I'm really struggling to update my ubuntu os... I've got three different versions of it on my pc namely Blackbox, twm & Kde/ kubuntu. However I can't access my software updater from any of them neither will my normal auto updates show.  Any suggestions please


How to add a cross-out "/" to any latex symbol?

I want to type something like this    How to add a / in a latex symbol in general? Like the \nexists, \notin.


Are Borg Drones able to adapt to projectile weapons?

The drones are able to adapt to energy weapons, but what about kinetic weapons like bullets or rail guns?


My bad questions are holding me to perpetual question bans. Revised

Everything I tried is in vain. If I ever want to ask a question I will have to open another account and never visit my old account again. This time I'll not make the same mistakes not to ever get banned again.  The below was written in hast. It is another question that is locked in by an answer that doesn't really help me but keeps me from deleting this question thus gaining more down votes.  I wish there was a way to get a full reset without abandoning this one?  I am asking for help is reestablishing my privileges asking questions on SE sites so I ca ask better constructed questions again. Will someone help me decide which questions on Meta can be improved and which are a total loss?   I understand asking which questions I asked are the lowest quality is broad but hopefully I can get direct guidance in specific questions I asked that needs the most revision.


How do I install dkms package without internet?

Just installed Ubuntu 20.04 on my laptop, replacing windows 10. My laptop's WiFi adapter (RTL8821CE) drivers weren't installed automatically, and I have no ethernet port so I have to manually do it. I found a guide online on how to download it but it assumes I have internet to download dkms. So I wanted to ask how do I manually download that as well?


Does anyone know the title of a book where an individual or group ventures through an Earth that is continually swept by timewaves which transport to different era?


Article: Author information when occupation has changed

I'm currently the main author of a paper. The work was performed when I was working at university X. However, I will start at a new university Y in one month, and the conference I'm presenting the work at is in two months. So, while presenting the paper I will be working at university Y (but the work was performed during my time at university X).  My question is the following, how would you present the author information:  A)     Both universities in the main information.  First name, Lastname (1, 2)    (1) University X  email@university_X.com    (2) University Y  email@university_Y.com   B)    Name and previous affiliation (where the work was completed) as the main information and the current affiliation in a footnote.  First name, Lastname  (Footnote: 'Currently working at University Y, email@university_Y.com')   University X  email@university_X.com     or C)    Name and current affiliation as the main information and the previous affiliation (where the work was completed) in a footnote.  First name, Lastname  (Footnote: 'Work completed at University X, email@university_X.com')   University Y,  email@university_Y.com     Or do you have any other suggestions?


Ubuntu 21.04 - how do I turn off hot top edge maximising windows

How do I turn off the top edge of the display from maximising windows in Ubuntu 21.04?


I have two small equations that I want to put into two columns, to save space. From this:   To this:


Illustrator - Text to SVG paths without fill

When I create text in illustrator and export it to SVG with the option Convert to Outlines, I get the following:    This is fine, except in the generated svg file there is inline CSS with the following:  <style>.cls-1{fill:#231f20;}</style>  If I change that to .cls-1{fill: none; stroke: #231f20;}, I then get the following:    This proves that the generated SVG is actually an outline around the letters, instead of the path through the letters. How can I get illustrator to generate the latter option?  Edit: Since no answers so far, here's more detail on what I'm trying to do. If I convert text to outlines, I get the following:    What I'm not clear is on the next step. Suppose I want to create "inner" paths that are lines and curves halfway between the inner and outer lines. Here's an example for the letter A:    In this case, 3 line paths are needed for the letter A.  Is there a way to generate these inner paths using a command or set of commands in illustrator?


Determine the group $\text{Aut}(\Bbb{Q}(\sqrt{2})$,where $\Bbb{Q}(\sqrt{2})=\left\{a+b\sqrt{2}:a,b\in \Bbb{Q}\right\}$.   First, identity and conjugation which is $a+ib\mapsto a-bi$. But I don't know whether there are some other elements in $\text{Aut}(\Bbb{Q}(\sqrt{2}))$. If we can prove that there is no other element, then $\text{Aut}(\Bbb{Q}(\sqrt{2}))\cong \Bbb{Z}_{2}$.


Tonight's Stack Exchange Android app isn't rendering correctly, and crashes more often, on Lenovo 10" Yoga

When viewing questions, regions of the screen paint over each other. And the app is falling on its face more often; I'll try to make sure you get trouble reports.  Removing/reinstalling didn't solve the rendering problem.


One way to show that there are infinitely many primes is to show that for $\forall n \ge 3$, there is a prime p such that $n \lt p \le n!-1.$ I thought of assuming that the numbers in the sequence $n+1, n+2,... n!-1$ are all composite and deducing a contradiction, but I don't know how to do this.


Is it correct to use "no?" after a question to get some kind of confirmation

We are going to the club tonight, no?   Is it correct?


Lenovo laptop: Is it ok to leave the battery charging while it is being used?

Is it ok to leave the battery charging while it is being use? Or is it ok to keep the power plugged in with full charged battery while the laptop is in use? Can this shorten battery's lifespan?


java.lang.NullPointerException: Attempt to invoke virtual method 'int android.widget.LinearLayout.getLeft()' on a null object reference

i got this error when i tried to implement Circular Reveal Effect. Does anyone have an idea?  private void ChooseFile() {      int cx = (mRevealView.getLeft() + mRevealView.getRight());         int cy = (mRevealView.getTop() + mRevealView.getBottom())/2;    // int cy = mRevealView.getTop();      int radius = Math.max(mRevealView.getWidth(), mRevealView.getHeight());


Unmet dependencies while trying to install python3-pip in Ubuntu 18.04

lokesh@lokesh-pc:~$ python3 --version Python 3.6.5 lokesh@lokesh-pc:~$ pip3 --version bash: pip3: command not found lokesh@lokesh-pc:~$ sudo apt-get install python3-pip [sudo] password for lokesh:  Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  python3-pip : Depends: python-pip-whl (= 9.0.1-2) but 9.0.1-2.3 is to be installed                Recommends: python3-dev (>= 3.2) but it is not going to be installed                Recommends: python3-wheel but it is not going to be installed E: Unable to correct problems, you have held broken packages.


What is the application/use to know about the order and degree of a differential equation?

A degree of a polynomial tells us the maximum number of possible roots of the equation. But what is the use to know about the order and degree of the differential equation. Like, what does it really tell us about the equation we are working with? For Example: If I am working with a polynomial of degree 3, and I tell that to you, you will be expecting, at most 3 roots of that polynomial. Degree of a polynomial only tells us about the number of roots, and so, x3 and x3 + 3x2 + 5 both are equation of degree 3 and tells it will have a maximum of 3 roots. But what does telling you that I am working with a differential equation of order 3 and degree 2 really tell you about the equation because you can not predict what the equation is, but then what can you predict with the data I give you? I am new in the Journey of Differential Equations and wanted to know about the things (and reasons) that I am learning. Thanks in advance for your answer. :)


No Terminal No Dashboard and No Window border in Ubuntu 14.04

I upgraded Ubuntu 12.02 to 14.04 and upgraded all packages with command sudo get-apt -f install. I dont know what happened but I am not even able to open Terminal or any applications. I can't see dashboard and window border. I dont know what to do? Please help me out from this problem.


$G/N = \{ gN  | g \in G \}$ is factor group where $N$ is normal subgroup of $G$. My doubt is that is it subgroup of $G$ ? Though I found it is not a subset of $G$. But how, my claim is that if we take $x \in  G/N$ so $x= an$ for some $a \in G$ and $n \in N$. We know $n$ belongs to $G$ as it is element of normal subgroup $N$. So $x= an$ should belongs to $G$.


Limit as $x\to 2$ of $\frac{\cos(\frac \pi x)}{x-2} $

I am a kid trying to teach myself Calculus in order to prepare for next year.   I have the expression  $$\lim_{x\to 2}\frac{\cos(\frac \pi x)}{x-2} $$  There is a hint that says to substitute t for $(\frac \pi2 - \frac \pi x)$ and WolframAlpha evaluates this expression as $\frac \pi4$. However, I got the answer of $1$. Can someone clarify the steps to solving this problem.


So I am currently a graduate student at the University of Colorado. I love math. From calculus to category theory to everything in between, I have tried and, for the most part, loved it. However, I also feel like it is important to help other people (particularly those less privileged.) My first thought was to work somehow with the World Bank  in some kind of applied math capacity, but I thought I would ask people here, what kinds of jobs can a mathematician aim for that will help other people, especially the poor? Thanks!! -DJ


Certainly a stupid question. I have a newcounter defined normaly, that is   \newcounter{sharc}   How can I call a specific value of this counter with a command like label/ref ?  Exemple  blabla  `\thesharc`  blala blabla  `\thesharc`  blabla blabla  `\thesharc`  blabla <- I want to refer to this value blabla  `\thesharc`  blabla


What's the shortest domain using HTTP (not HTTPS)

I'm usually dealing with different captive portals and having to sign in to have free WiFi. Sometimes the browser (Firefox for Android) or the OS detects the portal and redirects you to log in but other times that just doesn't happen and you have to visit one website so it can detect the captive portal. The problem is that when the web is a HTTPS website it takes longer or you just receive some annoying security warnings that require extra clicks. But also many times still the captive portal is not recognized. When that happens visiting a HTTP website just for detecting the portal makes everything more straightforward but nowadays fortunately there aren't left so many HTTP domains but for this purpose they can be useful. I'm visiting one domain that contains 11 characters that I won't mention because the website could be considered spam. So, in short, do you know any domain that is less than 11 characters that still uses HTTP? Thank you!


My company is evaluating becoming a Microsoft Dynamics Partner to do Dynamics installs.  We'll probably start with NAV 2009, because it seems to be the easiest to develop for.  However, we can't even find out what a typical Dynamics NAV 2009 license costs.  This is pretty important for us to know so that we can start to identify our market before investing in training, etc.  Does anyone know how much Dynamics NAV 2009 costs?


I want to have zero margin in my document, but there is no way I can't move it. Right now I can see that Document Margins have left: 0 in  However, I can see that there is some weird margin applied, but I don't know where it is set. I can not move the blue tip (see image)  Where am I supposed to move that tip to the left? Right now is 'blocked'.    Here is another picture to show what is going on...


Minecraft 1.16 Nether Fortress Location/Generation

The new Nether update has been released. I am asking about what is known about how the generation of nether fortresses will've been affected by this update. My old strategy for quickly locating a nether fortress was to travel in the x direction as one is most likely to appear this way. I've launched up multiple worlds and have attempted to use that strategy but it is to no avail - I often travel thousands of blocks without finding one. What is the most efficient way to now locate nether fortresses in Minecraft 1.16? Are they significantly rarer? Is it inevitable that on runs of Minecraft I'm pretty much always going to have to travel thousands of blocks for them?


How would I integrate  $$\int_{-\infty}^{+\infty} \frac{\sin^{2}(x)}{x^{2}}\,dx$$  using Fourier Transform methods, i.e. using Parseval's Theorem ?   How would I then use that to calculate:  $$\int_{-\infty}^{+\infty} \frac{\sin^{4}(x)}{x^{4}}\,dx$$?


I am trying to do a fancy resume and I want to include in it a pie skill chart (see image below). Any Idea on How Can I create this image in Latex.  Thank you for your help, Cheers


Using a high-end lens on a mid-range camera

Can I install Canon 1.2 lens on Canon eos 30d instead 5d and expect the same results?   In short, is it advisable to buy expensive lens and put it on medium range camera or both should be of equal stand to arrive at the best results?   Please answer both. Thank you.


Beamer: Trying to print a handout with notes, and it shrinks to like half the size

I am refloating  and will give a good bounty if somebody can solve it, cause it has been bothering me for the longest time, and cannot find a solution to it...  I have some problems when trying to make my Beamer presentations in handout format with notes, for printing and study them before the presentation day.  While the PDF seems to be generated with no problem, when trying to print it IT SHRINKS, and this happens with ALL THE PDF VIEWERS I HAVE TRIED, including Okular and Acrobat... This tells me that there is an inherent problem with the PDF itself...  This is the MWE I currently use:  \documentclass[handout]{beamer} \usepackage{pgfpages} \pgfpagesuselayout{2 on 1}[a4paper,border shrink=5mm] \setbeameroption{show notes on second screen=bottom}  \setbeamercolor{background canvas}{bg=pink}  \mode<presentation> {     \usetheme{Singapore} } \begin{document}   \begin{frame}[plain]     \titlepage   \note{     Notes for the title page } \end{frame}   \section*{Outline} \begin{frame}[plain] \frametitle{Outline}     \tableofcontents  \note{     Notes for the table of contents } \end{frame}   \section{Frame 1} \begin{frame} \frametitle{Frame with notes 1}     FIRST FRAME CONTENTS  \note{     Notes for the first frame } \end{frame}   \section{Frame 2} \begin{frame} \frametitle{Frame with notes 2}     SECOND FRAME CONTENTS \note{     Notes for the second frame } \end{frame}   \section{Frame 3} \begin{frame}     \frametitle{Frame with notes 3}     SECOND FRAME CONTENTS     \note{         Notes for the third frame     } \end{frame}   \end{document}   When I open the PDF with Okular, for example, it seems to open correctly (though the navigation links do not work):    But just going to the PRINT PREVIEW (same when actually printing), look what happens:    It shrinks to like half the size, and it has nothing to do with my printing properties, or with the printer...  Please help!!


Can I add to the blender ICONS? Where are the blender ICONS in window?  thanks


What is correct : 72 hour or 72 hours? In a article I have seen 72 hour rather than 72 hours.


Middle name missing on flight reservation, can I still fly?

As per passport my name is Manish Kumar Ahuja, but by mistake I book a ticket with the name of Manish Ahuja. My middle name is not on the ticket. Can I fly on this ticket? Because the airline can't add the name and they say that the ticket is non-refundable.


Formula for an ARIMA(1,1,1) solving for y

I have an Arima(1,1,1) model with  var1+var2+var3, but am struggling with how to write the equation. The problem is that on all of the sources I see a variation of the following is given.  $$\left( 1 - \sum_{i=1}^p \phi_i L^i\right) (1-L)^d y_t = \delta + \left( 1 + \sum_{i=1}^q \theta_i L^i \right) \varepsilon_t . $$  Is there a way to write the equation solving for $y_t$? I find that the above equation is difficult to understand. Though I have the model saved in R the users of the forecast want the coefficients so they can plug them into excel and I don't have a good way to explain the formula solving for $y_t$


How do I get rid of this orange selection box?

All i did was hit cntrl+b... Please help!


Show $\frac{1}{4}\leq \mu(A\cap B \cap C)$

Let $\{X,\mathcal{A},\mu\}$ be a probability space. Let $A$, $B$, $C$ be sets in $\mathcal{A}$, which satisfy $$\mu (A\cap B)\geq \frac{1}{2}, \quad \mu (A\cap C)\geq \frac{1}{2}, \quad \mu (B\cap C)\geq \frac{1}{2}.$$ Show that $\frac{1}{4}\leq \mu(A\cap B \cap C)$.  I've managed to show in a previous assignment that $$\mu(A\cap B \cap C)\leq \min\{\mu (A\cap B), \mu (A\cap C), \mu (B\cap C)\},$$ but now I'm stuck with the above inequality. I've tried to draw it, but still no luck. Any hints?


Community user badges on Sound Design and MathOverflow are not hidden like on all other sites

The Community user has badges on  and  .  While they are partially hidden, they are still visible, and they are also visible in the .  I guess this is partly because these sites have been imported in the SE network, not been created through the Area 51 process.


I want to make any elements inside of div to be centered vertically and horizontally.  Here's my HTML :  <!DOCTYPE html>   <title>Login</title>
     <form action="prosesLogin.php" method="post">
Login

Username	<input type="text" name="username">

Password	<input type="password" name="password">

<input type="submit" value="Login"> <input type="reset" value="Batal">

Belum memiliki akun ? Daftar

     </form>
     and this is my CSS :  .login{    height: auto;    margin: 0 auto;    border:1px solid blue; }   But it doesn't work, please tell how to make it. Thank you.


In quantum mechanics, how exactly do we associate Hermitian operators to classical observables?

In a first course on quantum mechanics, everybody learns some version of the following statement:     Postulate: To every classical observable $A$ of a physical system, there corresponds a Hermitian operator $\hat{A}$ such that a measurement of $A$ performed on  a system in state $|\psi\rangle$ is expected (in the probabilistic sense) to return $\langle \psi | A\psi \rangle$. Possible outcomes of the measurement correspond to eigenvalues of $A$...   One then learns that $\hat{x} = x$ is the operator corresponding to position, $\hat{p} = -i\hbar\frac{\partial}{\partial x}$ is the operator corresponding to momentum, and from these, one can construct the operators for the kinetic and potential energies, angular momenta, etc.  But what happens if we want to find the operator corresponding to some more complicated classical observable, say, $$ A = \frac{e^{\sin(x^2 p)}}{x+xp} + \cos\left(\frac{p}{x}\right)? $$ (Assume here that we've scaled $x$ and $p$ by some characteristic length and momentum, so that they become dimensionless.) Granted, this bizarre quantity might not have a compelling physical interpretation, but it is still in principle a classical observable, that can be computed with knowledge of $x$ and $p$. It seems to me that if we are to take this postulate seriously, there ought to be a well-defined procedure that associates to any function of $(x,p)$ a Hermitian operator acting on the appropriate Hilbert space. What is this procedure?  More generally, if we have some classical system $S$ with configuration manifold $M$, it seems to me that any real-valued function $f: T^*\!M \to \mathbb{R}$ on the phase space of $S$ (i.e., cotangent bundle of $M$) defines (in principle) a classically observable quantity. (Or does $f$ need to be continuous/smooth?) Quantum mechanics ought to prescribe a mechanism  that associates to any such $f$ some Hermitian operator $\hat{f}: L^2(M) \to L^2(M)$. What is this mechanism, and how does it work in general?


How can I send a private message to someone on Stack Overflow?

I cannot find a way of private messaging SO members, is it possible?


How to get client date and time in ASP.NET?

When I use DateTime.Now I get the date and time from the server point of view. Is there any way to get the client date and time in ASP.NET?


Tabs vs spaces in listings: what's the difference and should I care?

This is a follow-up question to . Why do I experience problems when I copy and paste code inside the lstlisting environment? Should I be careful about tabs or spaces in listings? And if yes, then why is that? How exactly do tabs and spaces affect horizontal spacing in source code typeset with the listings package?


how to add extra wallpapers to your desktop in ubuntu GNOME

i have recently switched to GNOME from unity and i just want to know how to add new background in it as it does'nt show the plus sign as shown in unity is there any other way to do it


List of names of standard fields as seen in report/layout metadata

If you look at the metadata for a related list in a page layout, you might see something like this:    <relatedLists>     <fields>Nopulous_Gateway__c</fields>     <fields>Status__c</fields>     <fields>Surripedous_Lair__c</fields>     <fields>Contact__c</fields>     <relatedList>Slomonious_Regency__c.Flubops__c</relatedList> </relatedLists>   However, if you are using a standard object, some objects and fields will be in all-caps and will not reflect their API Names:  <relatedLists>     <fields>TASK.SUBJECT</fields>     <fields>TASK.WHO_NAME</fields>     <fields>TASK.WHAT_NAME</fields>     <fields>ACTIVITY.TASK</fields>     <fields>TASK.DUE_DATE</fields>     <fields>TASK.STATUS</fields>     <fields>TASK.PRIORITY</fields>     <fields>CORE.USERS.FULL_NAME</fields>     <relatedList>RelatedActivityList</relatedList> </relatedLists>   You see these same all-caps names used in report metadata.  Where are these all-caps names documented?  If nowhere, what are the all-caps names that I can expect to see?


Coefficients in Shamir's Secret Sharing Scheme

Sorry if this is a stupid question, but: in Shamir's scheme, we construct a polynomial and make our secret $S$ the zero-th coefficient $a_0$. What, if anything, necessitates this - in other words, can we make include $S$ as $a_1$ or any other coefficient?


Let $f$ be a continuous mapping of a compact metric space $(X, d)$ onto a Hausdorff space $(Y, \tau_1)$.  If $d$ is a metric on $X$, how to show that  $$d_1(y_1, y_2) := \inf\{d(a, b) : a \in f^{-1}(y_1)\text{ and }b \in f^{−1}(y_2)\}$$ is a metric on Y?  I can see that it is never $0$ when $y_1$ is not equal to $y_2$. But how should I go about showing that it satisfies the triangle inequality?  I am actually reading the following page from a book.


I have two particular questions regarding the inflationary scenario. They are:  What is the physical origin of the inflaton field?  Why has the potential of the inflation field its particular form?


The twin paradox in a universe with a torus topology

It's a question that was bothering me for some time. In special relativity one can consider the "twin paradox", where one twins leaves earth and returns, staying young while the twin left behind grows older. This is not a paradox because the twin in the spaceship accelerates to change his direction when turning back- therefore he is not in an inertial frame.  However, in a universe with the geometry of a flat torus, one can go "around" the universe and return to earth without accelerating or experiencing any intrinsic curvature of the universe. In this situation the paradox rises again: which twin is older and which one is younger, considering that both twins' frames of reference are valid?


sort list of dictionaries based on "sub-string" present within dict's value string

I have a list of dictionaries in python, called all_data. The structure of each dict object hold by all_data is:  {     'href': u'http://malc0de.com/database/index.php?search=c.img001.com',      'type': u'text/html',      'rel': u'alternate',     'title': u'c.img001.com',      'summary': u'URL: c.img001.com/re58/girlshow_20300025849.exe, IP Address: 14.215.74.85, Country: CN, ASN: 58543, MD5: 31d5f481153ccd2829558720f8d90d81',      'title_detail': {         'base': u'http://malc0de.com/rss/',          'type': u'text/plain',          'value': u'c.img001.com',          'language': None      } }   I want to perform sorting base on the name of 'Country' which is present as sub-string to the value of 'summary' key. The content of string is like:  u'URL: c.img001.com/re58/girlshow_20300025849.exe, IP Address: 14.215.74.85, Country: CN, ASN: 58543, MD5: 31d5f481153ccd2829558720f8d90d81',    I want to sort the list of dicts based on the Country name in the alphabetical order.


Convert Xamarin Essentials (Preview) MediaPicker into a Byte[]

I want to take the new implementation of taking a photo then converting it into a byte[] using the preview version of Xamarin Essentials See below the code I have to take the image then load it. async Task TakePhotoAsync() {     try     {         var photo = await MediaPicker.CapturePhotoAsync();         await LoadPhotoAsync(photo);         Console.WriteLine($"CapturePhotoAsync COMPLETED: {PhotoPath}");     }     catch (Exception ex)     {         Console.WriteLine($"CapturePhotoAsync THREW: {ex.Message}");     } }  async Task LoadPhotoAsync(FileResult photo) {     // canceled     if (photo == null)     {         PhotoPath = null;         return;     }     // save the file into local storage     var newFile = Path.Combine(FileSystem.CacheDirectory, photo.FileName);     using (var stream = await photo.OpenReadAsync())     using (var newStream = File.OpenWrite(newFile))         await stream.CopyToAsync(newStream);      PhotoPath = newFile; }  I want to take the image and convert it into a byte[]


I just started learning about $L^p$ spaces today and I have this question: Let $(X,\scr{M},\mu)$ be a measure space. Let $f:X\rightarrow \mathbb{C}$ be measurable. Consider $\eta:]0,\infty[\rightarrow[0,\infty]$ that sends $p$ to $||f||_p$. Is $\eta$ continuous ?  My approach was to show that the function $p\rightarrow \int_X |f|^P d\mu$ is continuous by showing that for every sequence $\{p_n\}$ that converges to $p$ we have  $\int_X |f|^{p_n}d\mu$ converges to $\int_X |f|^p d\mu$ using Lebesgue's dominated convergence theorem, but I couldn't as I wasn't able to find a dominating function. I also think that the claim of my approach is stronger than the claim "$\eta$ is continuous".  Thank you


What are the differences between Linux and Windows .txt files (Unicode encoding)

I am only using the 128 character set defined in the original ANSI standard.  But as a whole how are the files implmeneted differently.    I am not concerned with the display, i.e. if a tab is displayed with 6 or 8 characters but the actual internal representation in memory  One difference I've heard is the use of \r\n (Windows) vs. \n for line termination (Linux).


Let $g(x)=1+x+2x^2+2x^3+3x^4+3x^5...=\sum_{n=0}^{\infty} \lceil {\frac{n+1}{2}} \rceil x^n$ (the ceil function). What is the radius of convergence of this function? I attempted this question by using the root test: $\lim_{n \to \infty} \frac{x^{n+1} \frac{n+2}{2}}{\frac{1}{x^n}\frac{2}{n+1}}$. i simplified the terms and got limit $= 1$. So the radius of convergence is 1?


I am cloning dom with jQuery append. Then I check the input value. The change and keyup functions do not work. But the input I created with jQuery append is not perceived. Can you help with this ?  Html      $(".email-address").on('change keyup', function (e) {         alert("test");         });   jQuery      $('.add-extra-email-button').click(function() {         var newDiv = $('

');          newDiv.html('
<input type="email" class="form-control email-address" name="email[]" placeholder="E-Mail">
');          $('.clone').append(newDiv);     });


Sometimes one needs two disjoint copies of a given set $X$. This can be canonically done by taking $\{0\} × X$ and $\{1\} × X$. Sometimes we want to identify one of the copies with the original set $X$. So I wonder, is it possible to take a disjoint copy of $X$ straight ahead? And can this be done canonically? More precisely, are the following claims true? $ \def\dom{\operatorname{dom}} \def\rng{\operatorname{rng}} \def\On{\mathbf{On}} $   For every $X$ there is a one-to-one function $f$ such that $\dom(f) = X$ and $\rng(X) ∩ X = ∅$. There is an explicit formula $φ(X, f)$ such that for every $X$ there is exactly one $f$ satisfying $φ(X, f)$ and this $f$ satisfies 1. for $X$.   Since such construction of a disjoint copy is intuitively trivial, I'm interested in proofs of 1. and 2. without using regularity, choice, or infinity.   Some ideas:   We may simply put $f(x) := (x, X)$, but we need regularity to show that $(x, X) ∉ X$. We may consider $α = \sup(X ∩ \On)$ and pair members of $X$ with some ordinals above $α$, but we need AC to well-order $X$, and we need global choice to obtain 2. Let $<$ be the transitive hull of $∈$. If the relation $<$ is narrow, i.e. $\{y: y < x\}$ is a set for every $x$, then we may choose $z ∉ ⋃\{(\leftarrow, x)_<: x ∈ X\}$ and put $f(x) := (x, z)$ since $(x, z) = y ∈ X$ would imply $z < y$. Note that we don't need the axiom of infinity to define $<$, but I don't know how to prove its narrowness without infinity.


I am currently working on converting my logo vectored as a SVG to a 3D model using the 2.72 version. I ran into a problem with my logo because it contains a black stroke and an orange stroke (see both images below), but currently all I have is the interior color of each shape. I was wondering whether or not there was a simple way to add in these strokes, and how exactly to go about creating the strokes. Thank you in advance community!


Excel text alignment with custom formatting

Is there anything in a custom formatted formula which defines the text alignment?  I know the different parts of the formula is numbers, negative numbers and so on, but I need to set the alignment.  Example:  _*# ##0_;_*(# ##0)_;_*"-"??_;_@_


Show that $X$ can be represented as a union of disjoint equivalence classes

Let $X$ be a set. Let $\sim$ be an equivalence relation on $X$. Show that $X$ is the union of disjoint equivalence classes $\{x\}$ for $x \in X$.  What I have tried:  claim: $X = \bigcup_{x\in X} \{ x \}$  indeed, $\{x \} \subset X ;\forall x$ hence $ \bigcup_x \{x \} \subset X$.   Suppose $y \in X$ then here I am stuck - is it OK to write that $y \sim y$ so $y \in \{y \}$? I am not sure I can do that, but if I could it would finish the proof. Any help please


We're rolling out a new "Quick Start" guide to help new users learn the basics

on Ask Different.  We've been working hard on ways to help improve the experience of new users, and one of the best ways to do that is to help teach them the basics about how our sites work before they run afoul of them.  This will improve their odds of having a good first experience, speed up how quickly they can become contributing members of community, and head off the frustrations they sometimes have as a result of crashing into one of the many things that make us... different.  So We've just rolled out the first version of our new "quick start" guide. It's designed to help teach new users the absolute minimum they need to know to get started and have a good experience. How we're different from discussion boards, the basics of rep, what you can do right off the bat, why some questions aren't allowed, etc.  We spent a LOT of time on trying to get to the absolute minimum length that will still cover the key things new users need to know to be successful, but if you have feedback, please share it.


Change the Python3 default version in Ubuntu

I am using Ubuntu 16.04 LTS . I have python3 installed. There are  two versions installed, python 3.4.3 and python 3.6 . Whenever I use python3 command, it takes python 3.4.3 by default. I want to use python 3.6 with python3. python3 --version shows version 3.4.3 I am installing ansible which supports version > 3.5 . So, whenever, I type ansible in the terminal, it throws error because of python 3.4 sudo update-alternatives --config python3 update-alternatives: error: no alternatives for python3


How to prove this Fibonacci sequence statement: $F^2_{n+1} - F^2_{n-1} = F_{2n}$

So the statement is:  Prove: $$F^2_{n+1} - F^2_{n-1} = F_{2n}$$  How could this be proven with induction?  What about without induction?  For induction I got here: (already tested $n=1$, and assumed $n=k$ held true)  $$F^2_{k+2} - F^2_{k} = F_{2k + 2}$$ $$(F_{k+1} + F_{k})^2 - (F_{k-1} + F_{k-2})^2 = F_{2k+1} + F_{2k}$$ Then you get some cancelation based off the $n=k$ case $$2F_{k+1}F_k + F_k^2 - 2F_{k-1}F_{k-2} - F_{k-2}^2 = F_{2k+1}$$  This is where I am stuck for the induction proof.  I have no idea where to begin with the non-induction proof.


Dealing with non-linear variable in multiple linear regression model

I have a multiple linear regression model which should explain the variation store price elasticities using consumer characteristics of the market area surrounding a store. Therefore, my dependent variable are 74 different PE. My independent variables are income (log median income), education level, elderly and household size. The problem I am dealing with is that income and PE show a non-linear (parabolic) relationship in my category (beer).     The values of income range from 9.8 to 11.2. Now my professor gave me two options:   Tranform the variable (square)   demoreg <- lm(pe ~ squaredincome + income + educ + hhlarge + age60, data = demo) summary(demoreg)   I feel like there is a mistake but how can I interpret the income coefficient(s)?  Coefficients:               Estimate Std. Error t value Pr(>|t|)     (Intercept)  64.588934  34.506386   1.872 0.065735      sqincome      0.569562   0.315751   1.804 0.075892      income      -12.437625   6.592960  -1.887 0.063696      educ          0.019858   0.005524   3.595 0.000626     hhlarge      -0.029244   0.013254  -2.207 0.030886     age60         0.012861   0.005902   2.179 0.032947  Residual standard error: 0.2441 on 65 degrees of freedom Multiple R-squared:  0.5755,    Adjusted R-squared:  0.5428  F-statistic: 17.62 on 5 and 65 DF,  p-value: 5.376e-11  Option:  Create two variables one for all income levels that show a negative relationship and one for all income levels that show a positive relationship so I get two coefficients that show how much the PE changes if the median income changes 1%.  PE = β0 + β1* income_low + β2* income_high   As the low is at 10.6, I created a dummy variable:  data$dummylow  <- ifelse(data$income <= 10.6,1,0) data$dummyhigh <- ifelse(data$income >10.6,1,0)  data$low       <- ifelse(data$dummylow ==1, demo_clean$income, NA)  #$ data$high      <- ifelse(data$dummyhigh ==1, demo_clean$income, NA)   If I include now both variables in the regression equation I get the error code:  demoreg <- lm(pe ~ low + high + educ + hhlarge + age60, data = demo) lm.fit(x, y, offset = offset, singular.ok = singular.ok, ...) All cases NA   I want to include both variables in the equation as I need two coefficients, but I don't know how to do it.


Sense of humor allowed in academic writing?

I'm reading a paper at the moment and very bored and then I thought if I write a paper, I would like the writing style to be not so boring or having some kind of humor. Is that allowed in academic writing?  "Why so serious?" - Joker.


An Infinite Double Summation $\sum_{k=1}^{\infty} \sum_{n=1}^{\infty} \frac{1}{n^2k^2(n+k)^2}$?

While Solving some integral problem, I encountered the following infinite series:  $$\displaystyle \sum_{k=1}^{\infty} \sum_{n=1}^{\infty} \frac{1}{n^2k^2(n+k)^2}$$  I have tried many methods including partial fractions... I seek help! Please provide hints if you don't have the complete answer.


I know this is incorrect: John and me will be giving a birthday treat.  I know this is correct: John and I will be giving a birthday treat.  But what when the voice is changed? Birthday treat from John and I? Birthday treat from John and me?


I am using a  and am unable to eject the hard disc from my laptop .   I have tried to right click and eject but i get the following error message :    I have tried the following from  but it does it work also.   Is there any other way to eject my disc ???


reaction numbering with chapter numbers chemmacro

I am trying to use the  reaction environment from chemmacro. How to get the numbers with chapter number like for equation numbers (e.g 1.1, 2.1 and so on)  \chapter{The First Chapter} \begin{reaction}     a + b = c \end{reaction}  \begin{equation}  a + b =2 \end{equation}


game object disappears when I add OnTriggerEnter script

I'm setting up collision detection for my enemy objects and projectile. When I add the detect collision script below, my enemy object just disappears. Projectile has the same detect collision script and also disappears. I get this error code: NullReferenceException: Object reference not set to an instance of an object MoveForward.Start () (at Assets/Scripts/MoveForward.cs:16) This is a copy of my prefab settings for enemy object:  I'd appreciate any advice. Thank you Detect Collision Script using System.Collections.Generic; using UnityEngine;  public class DetectCollision : MonoBehaviour {   // Start is called before the first frame update   void Start()   {    }    // Update is called once per frame   void Update()   {    }    private void OnTriggerEnter(Collider other)   {     Destroy(gameObject);     Destroy(other.gameObject);   }  }   Move Forward Script using System.Collections; using System.Collections.Generic; using UnityEngine;  public class MoveForward : MonoBehaviour {   public float speed = 20f;   public GameObject Trump;   public GameObject Player;   private Rigidbody enemyRb;   // Start is called before the first frame update   void Start()   {     enemyRb = GetComponent<Rigidbody>();     Player = GameObject.Find("Player");     this.transform.LookAt(Player.transform);     }    // Update is called once per frame   void Update()   {     transform.Translate(Vector3.forward * Time.deltaTime * speed);            } }


What Sith Lords were turned to the Light Side?

I have heard of a ton of Jedi who have turned to the Dark Side and became a Sith (Exar Kun, Darth Malak). I've even heard of a few Jedi who have turned to the Dark Side and then found their way back to the Light (Revan, Anakin, Qel-Droma). But I cannot seem to recall any Sith who turned to the Light Side. I think I might have read of one, but I cannot remember the name or story.  Are there any Sith who have turned to the Light? Hell, have there even been any Sith that have turned to the Light Side and then returned to the shadows of the Dark Side?


I have more media that can possibly be stored on my iPhone, so I assume that most of it is stored in iCloud and downloaded when required (when I view it).   What happens if I cancel/downgrade my iCloud storage plan?  How do they decide what media is going to be deleted, so that the amount falls within the free plan?   Is there a time period where I can cancel and then sign back up and it'll be as if nothing has happened?


I know that a gas is made of atoms or molecules moving freely in space.  When these particles hit the walls of where they're kept in they cause something called pressure.  But these particles never pile up on each other and push a surface down by their weight so that we can measure it as weight, not pressure.  So why do gases have weight?


Another question on almost sure and convergence in probability

Convergence in probability implies convergence on a subsequence almost surely.  But this means we fix a subsequence, such that $X_{n_k}$ converges for almost every $\omega$, right? The subsequence we pick does not depend on the $\omega$ right?


I have two layers. Layer 1 contains points (x,y) and layer 2 contains one polygon. All points in layer 1 are positioned within the polygon of layer 2. The points in layer 1 contain an attribute with information on the topography/elevation at the specific point. Can I color the polygon in layer 2 based on attributes from the points in layer 1 in order to create an elevation map?


How do you mark a struct template as friend?

I have code like this:  template <typename T, typename U> struct MyStruct {     T aType;     U anotherType; };  class IWantToBeFriendsWithMyStruct {     friend struct MyStruct; //what is the correct syntax here ? };   What is the correct syntax to give friendship to the template ?


I know that on windows you can index your files to find things faster. Is there something like this for Ubuntu because when I search for something like /usr under files it says searching and it takes really long.


count number of ones in a given integer using only > + | & ^ ~ ! =

How to write a C program using only << >> + | &  ^ ~ ! = That counts the number of ones in a given integer?


I want to verify integrity of folder. The folder has so many files and folders. How to calculate hash value of directory as a whole on Ubuntu. md5sum calculate at only file level.


Im arguing with some friends whether it is necessary to put parenthesis around a sum in an integral: can we write $\int_a^b x^2+x ~ \mathrm d x$ or do we need to write $\int_a^b(x^2+x)\mathrm d x$?  My friends are arguing that we are not integrating $f$ but rather the differential form $f\cdot \mathrm d x$. Since this is a product we need parenthesis if $f$ is replaced by a sum.  My argument is, that i see the integral as an operator $\int_a^b \cdot \mathrm dx: L^1\to\mathbb C$, so the full notation would be $\int_a^b (x\mapsto x^2+x)dx$. Both of the suggestions above would then just be shortcuts to save some time and the necessity of paranthesis would then just be an arbitrary cut of how much of a shortcut is allowed.  I think both arguments do have some validation.   So my questions: Do we need them or don't we?


How do I get the modified date/time of a file in Python?


Why does all the current flow through a short circuit if its voltage drop is considered zero?

I know the path of least reisistance has been clarified already However, to derive the equations you need to assume that the voltage of each parallel component is equal. But we know for a short circuit current the voltage is zero (By Ohm's law!) So there is a glaring contradiction!


How to engage in the scientific committee of a conference?

I have published few papers with high impact factors in power systems already and graduated with M.Sc. couple of years ago. I am a reviewer in couple of top journals like IEEE as well.   I thought it would be exciting to enroll in scientific committee of a conference in my field, electrical eng. power systems, specially abroad. Well my question is:      How can I find a conference to engage in their scientific committee?   What qualifications should one have for that?   Is it normal to apply for this by email online? and how?


In some legacy code I see this, that an overbroad exception is being caught, and then thrown again, Is this a good practice?  Does throw e; rethrow the same exception, or create a new one ?   catch (Exception e) {         StringBuilder sb = new StringBuilder(                             "Oops. Something went wrong with id: ");         sb.append(id);         sb.append(". Exception is: ");         sb.append(e.toString());         System.out.println(sb.toString());         throw e; }


I think I'm having a compiler problem. If I try this:      \documentclass[11]{article}  \usepackage{cite} \begin{document}  \bibliographystyle{plain} \bibliography{mybib}  \end{document}   Having made a mybib.bib file as:  %%%%%%%%%%% mybib.bib %%%%%%%%%%%%%%%%%%% @BOOK{HK,  AUTHOR={H. Kopka and P. W. Daly},  TITLE={A Guide to LaTeX},  PUBLISHER={Addison-Wesley},  ADDRESS={Reading, MA},  YEAR=1999.  } @BOOK{MG,  AUTHOR={M. Goossens and F. Mittelbach and A. Samarin},  TITLE={A LaTeX Companion},  PUBLISHER={Addison-Wesley},  ADDRESS={Reading, MA},  YEAR=1994.  } @ARTICLE{Pan,  AUTHOR={D. Pan},  TITLE={A Tutorial on MPEG/Audio Compression},  JOURNAL={IEEE Multimedia},  YEAR={1995},  VOLUME= {2} ,  PAGES={60-74},  MONTH={Summer}. } @INPROCEEDINGS{Boney96, AUTHOR={L. Boney and A. H. Tewfik and K. N. Hamdy}, TITLE={Digital Watermarks for Audio Signals}, booktitle={Proceedings of the Third IEEE International Conference on Multimedia}, PAGES={473-480}, MONTH={June}, YEAR={1996}. } %%%%%%%%%%%%% end %%%%%%%%%%%%%%%%%%%%%%   When I compile, I don't even generate a .pdf file. Why so?


Where do I find the current C or C++ standard documents?

For many questions the answer seems to be found in "the standard". However, where do we find that? Preferably online.  Googling can sometimes feel futile, again especially for the C standards, since they are drowned in the flood of discussions on programming forums.  To get this started, since these are the ones I am searching for right now, where are there good online resources for:   C89 C99 C11 C++98 C++03 C++11 C++14 C++17


Calling method using JavaScript prototype

Is it possible to call the base method from a prototype method in JavaScript if it's been overridden?  MyClass = function(name){     this.name = name;     this.do = function() {         //do somthing      } };  MyClass.prototype.do = function() {       if (this.name === 'something') {         //do something new     } else {         //CALL BASE METHOD     } };


How do I make the following in a TeX file? I try a lot of things but still don't work.


Suppose that $I=(-a,a)$ for some $a>0$. A function $f:I \to \mathbb{R}$ is said to be even if and only if $f(-x)=f(x)$ for all $x \in I$, and said to be of odd if and only if $f(-x)=-f(x)$ for all $x \in I$ Prove that if $f$ is odd and differentiable on $I$ ,then $f^\prime$ is even on $I$ since $f$ is differentiable on $I$,  by definition for all $b \in I$ $$f^{\prime}(b) :=\lim_{x\to b} \frac{f(x)-f(b)}{x-b}=\lim_{x\to b} \frac{-f(x)+f(b)}{-x+b}=\lim_{-x\to -b} \frac{f(-x)-f(-b)}{(-x)-(-b)}=f^{\prime}(-b)$$ for all $b \in I$ thus $f^{\prime}(x)=f^{\prime}(-x)$ Is that correct? I know taking derivative of $f(-x)=-f(x)$ is also correct but I want to check this


My prisoners wont move from the holding to cell to the actual cell

I have a cell block with 25 cells but none of my prisoners will move there from the holding cell. I have working power and water beds and toilets they are separate from each other it has all the requirements why wont it work? Any ideas?


How to use a JSON ENCODED data to Javascript array?

I have some pages on the web which echo results like:  [{"id":"1","company":"Gaurishankar","bus_no":"JHA 12 KH 1230"}, {"id":"2","company":"Gaurishankar","bus_no":"BA 2 KH 2270"}]   I want to use this json_encode data to be used in Javascript array like:  var data = http://api.mywebsite.com/get_data.php; for (i = 0; i<data.length; i++){ //Do something here }   How is this possible. I know its easy but I cant make this. I am a new learner. Plz help


I am updating record on the base of sub query but it giving me error      you can't specify target table for update in from clause   my query is   UPDATE paymentinfo set customer_id =  (    SELECT transation.transactionid     FROM paymenttransaction AS transation     LEFT JOIN paymentinfo as payment     ON (transation.paymentinfoid=payment.paymentinfoid)     where payment.hash="0b576d33c57484692131471a847eab7c" )  WHERE hash="0b576d33c57484692131471a847eab7c"   where am i wrong and what will be perfect solution for that problem


Identify a story about running from a relentless chasing machine or bot

I am trying to identify a story I read decades ago that I visualize this way and often think about when I am cross country running:   There is a machine that I visualize as round, with some way to destroy people (such as injecting them with something) that relentlessly chases the protagonist to run him down.   I seem to associate the name Ruun with the story.


I'm not sure if I have an issue or if what I am seeing is by Apple-design.  I have an iPad Pro (11.4) that I have the Personal Hotspot switched on.     My iPad Pro is active and screen on. I connect my iPhoneX (11.4) to the iPad Hotspot. Everything works fine.  I sat working on laptop and then the iPhone X and iPad screen locked.  After X minutes I then unlock iPhone to check email etc..  The iPhone X has disconnected from the hotspot and is back to using the cellular plan on my iPhone.  If I go to Settings -> Wi-Fi then my iPad is not listed.  To make the hotspot reconnect I have to go back to my iPad and toggle the Personal HotSpot switch (On -> Off -> On).   Is this by design or not?  Should the iPhone remain connected if the devices screen lock?


In US with multiple entry tourist visa. Can I go to Mexico and come back without issues?

I am an Indian Citizen currently visiting US on a Multiple Entry tourist visa. I am planning a short ( 6 days) trip to Mexico and then return to US. Do I need a Mexican visa? Will there be any problem while re-entry to US?


A list of different measures of distance/difference/dissimilarities/similarity of two probability distributions?

I wanted to know more about the different methods for comparing the similarities of two probability distributions P and Q.  I wanted a list of the different methods that exist for comparing probability distributions.  For example, the two that I am aware that exist are:   KL-Divergence EMD (earths mover's distance)   I was wondering if people knew about more different measures and if they could provide maybe a good reference for learning about it. Also, on top of providing the distance measure that you are suggesting, if you could provide a brief intuition on it before I research it more, it could be very helpful!


Convergence of a Series $\sum_{n=1}^{\infty}\left(\frac{n}{n+1}\right)^{n^2}$- Which Test?

I tried root and ratio tests but it didn't work. Also, i can't use integral tests (and other "uncommon" ones) in this homework.   (Prove that the series is convergent) $$\sum_{n=1}^{\infty}\left(\frac{n}{n+1}\right)^{n^2} = \frac{1}{2} + \left(\frac{2}{3}\right)^4 + \left(\frac{3}{4}\right)^9 + ...$$


Determining if $A(B(x))$ is a formal power series

I know that by a theorem, $A(B(x))$ is a formal power series if $b_0=0$. I wasn't sure if it works the other way around.  Can I also say that if $b_0\ne0$, $A(B(x))$ is not a formal power series?  If it doesn't work the other way around, what other techniques can I perform to determine if $A(B(x))$ is a formal power series when $b_0\ne0$?


How to connect a Nokia Lumia 730 to Ubuntu 14.04?

I have trouble to connect my new Nokia 730 to Ubuntu 14.04.  I tried some solution I found searching WEB (like this one: ) but nothing helped. My File-Manager Thunar (I am using XFCE) shows also that something is mounted, but when I click on each icon, following error appears:  In German:     Der Datenträger »Lumia 730 Dual SIM (RM-1040)« konnte nicht eingehängt werden. Fehler beim Initialisieren der Kamera: -1: Unspecified error.   English (automatically translated from askubuntu):     The disk » Lumia 730 Dual SIM (RM -1040 ) " could not be mounted. Failed to initialize the camera : -1: Unspecified error   The Nokia is plugged in but recognized wrongly, as a camera!  With Android I had no problems and the two icons in Thunar pointed respectively to the phone and to the card. The MTP worked with Android and I don't think is a missing MTP tools. I tried and installed all I needed, but with Windows phone does not work correctly.  Can anyone help me and give me a solution?  My Systemlog shows following informations:   kernel: [  461.933996] usb 3-10: new high-speed USB device number 12 using xhci_hcd  kernel: [  461.965116] usb 3-10: New USB device found, idVendor=0421,  idProduct=06fc  kernel: [  461.965125] usb 3-10: New USB device strings: Mfr=1, Product=2, SerialNumber=3  kernel: [  461.965130] usb 3-10: Product: Lumia 730 Dual SIM (RM-1040)  kernel: [  461.965134] usb 3-10: Manufacturer: Microsoft  kernel: [  461.965138] usb 3-10: SerialNumber: 1100000058BE4FB90000000000000000  colord: Device added: sysfs-Microsoft-Lumia_730_Dual_SIM__RM-1040_  colord: Device added: sysfs-(null)


"I am done" or "I have finished" or "I am finished" or "I finish"

I was trying to say the following and got bewildered with the different choices.     I have "To Kill a Mockingbird" on my list. I will write you about it when I am finished reading it.      I have "To Kill a Mockingbird" on my list. I will write you about it when I have finished reading it.      I have "To Kill a Mockingbird" on my list. I will write you about it when I am done reading it.      I have "To Kill a Mockingbird" on my list. I will write you about it when I finish reading it.   I am not sure which one to pick. I am confused with the exact meanings of these various choices. Could someone also shed some light on what meanings the different tenses convey in a context like this.


Why did Snoke’s ship’s weapons arc like this?

As the       Resistance ships are running away and the transports are being picked off one by one   the shots fired travel in what appears to be a parabolic trajectory, arcing “up”, then back “down” to hit their targets. But since in space there’s no up and down defined by a main gravitational force, why would the projectiles not simply travel in a straight line?  Cinematically the visual effect seems to be derived from something like a catapult or trebuchet. But why in the Star Wars world would a weapon behave like that? In-universe answers only, please.


Citing multiple authors with alternate separator than "and" using BibTeX

I'm using LyX on Linux Mint 14 ...  Using BibTeX with the apalike style and some modifications in the preamble, I've managed to get the bibliography as it should be except for one thing. When I cite a work with multiple authors it gets printed with the separator "and" which isn't correct for my language (Danish). Curiously it's displayed correctly in the user interface of Lyx - for example "(Wittgenstein og Waismann 2003 - which led me to believe everything was ok but in the pdf the separator "and" is used both in the reference and in the bibliography.  Is there any way to fix this using BibTeX, or can it only be done with biber 1.5, as suggested in the last comment here:   I really hope their is because getting biber to work using the following guide has thus far proven to be impossible:   Help much appreciated ... I really hope I won't have to relapse into setting my master thesis up in LibreOffice.


How can a router log in to a wireless network that requires an in-browser password?

At our apartment complex there's a wi-fi network for all the residents.   There's no password to access the network itself (no WPA password, for example).  Instead, there's a password that you have to enter using your browser in order to access the internet. Each apartment can only log on with one device.   I'm planning to set up a wireless network in my home that lets me connect multiple devices to it (as described in my ).  How can my router / wireless repeater become the one device connected to the complex's network, since it doesn't have a browser interface to enter a password in.  In short,  How can my router enter an in-browser password?  (Strange idea)  Could I log in with my laptop, then tell my router to change its MAC address to match my laptop's?  Would that cause a problem, for my laptop and wirelss router to have the same MAC address?


Use the Fitch system to prove the tautology (p ∨ ¬p). Stalled for days

I'm having trouble solving this one. I've been stuck in step 9 for days now. Any help is very much appreciated.


What is a good Read, Eval, Print, Loop implementation for C#?

Some programming language implementations provide a Read, Evaluate, Print Loop interactive shell to allow the programmer to evaluate expressions and program fragments, and to program in an incremental, interactive manner.  What implementations of a C# REPL have you used, and liked? It would be nice to have one that could integrate with Visual Studio as well.  I have found, but not tried, the  and


Time of Day, Day of Week and Question Popularity

In my experience, question popularity has a lot to do with what time-of-day it's asked. Also, I suspect that the day of the week is important too. These are just suppositions, however. Does time of day and day of the week in which a question is asked affect its popularity? If so, when and how?


Can't install git and openssh-client - "held broken packages" and "no installation candidate"

I am trying to install git on Ubuntu 14 with the following code  sudo apt-get install git   I get this output :  The following packages have unmet dependencies:  git : Depends: liberror-perl but it is not installable        Recommends: ssh-client E: Unable to correct problems, you have held broken packages   I am trying to install ssh-client by the following code:  sudo apt-get install openssh-client   then get this error:    Reading package lists... Done Building dependency tree        Reading state information... Done Package openssh-client is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source  E: Package 'openssh-client' has no installation candidate


Is 50 minutes enough time to transfer between Terminal A and C at Newark (EWR)?

We'll be arriving at Newark airport (with two kids under 7) at Terminal A and our flight connection is in Terminal C. Is that enough time to catch the connecting flight?  Update: both flights are on United.


Variable expansion did not happen in /etc/environment

I changed the /etc/environment to add more directories to the PATH variable. But looks like $PATH in double quotes were not expanded and I could find any command from the shell and /usr/bin/command-not-found is run.  $ cat /etc/environment  PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games" PATH="$PATH:/home/user/technical/java/maven/bin" JAVA_HOME="/home/user/technical/java/jdk7"   so from the tty,  $ echo $PATH $PATH:/home/user/technical/java/maven/bin   why did not the expansion happen?


Villager trade issue with canplaceon item

I have this command: /summon villager -179 64 95 {VillagerData:{profession:farmer,level:2,type:plains},Invulnerable:1,NoAI:1,CustomName:"\"Gardener\"",Offers:{Recipes:[{buy:{id:gold_nugget,Count:3},sell:{id:wheat_seeds,Count:3,CanPlaceOn:["farmland"]},rewardExp:0b,maxUses:9999999},{buy:{id:wheat,Count:1},sell:{id:gold_nugget,Count:3},rewardExp:0b,maxUses:9999999}]}}  Formatted: /summon villager -179 64 95 {   VillagerData {      profession:farmer,     level:2,     type:plains   },   Invulnerable:1,   NoAI:1,   CustomName:"\"Gardener\"",   Offers:{     Recipes:[{       buy:{         id:gold_nugget,         Count:3       },       sell:{         id:wheat_seeds,         Count:3,         CanPlaceOn:["farmland"]       },       rewardExp:0b,       maxUses:9999999     },{       buy:{         id:wheat,         Count:1       },       sell:{         id:gold_nugget,         Count:3       },       rewardExp:0b,       maxUses:9999999     }]   } }  It works pretty well, but these seeds being sold cannot be placed on farmland. anybody understand why it doesn't work?


If I want to print multiple figures in figure, I'm using subfigure in the figure environment. This work quit well and is looking smart, if all figures have the similar height. Now there is this figure which is more than two times higher than the other ones. I would like to order the subfigures like its shown in the following picture:     But I don’t know how to get this into Latex.   My regular code for four subfigures:  \begin{figure} \centering \begin{subfigure}{0.32\textwidth}    \centering    \includegraphics[width=\textwidth]{highone}    \caption{}    \label{fig:a} \end{subfigure} \begin{subfigure}{0.32\textwidth}     \centering     \includegraphics[width=\textwidth]{b}     \caption{}     \label{fig:b} \end{subfigure} \begin{subfigure}{0.32\textwidth}     \centering     \includegraphics[width=\textwidth]{c}     \caption{}     \label{c} \end{subfigure} \begin{subfigure}{0.32\textwidth}     \centering     \includegraphics[width=\textwidth]{d}     \caption{}     \label{fig:d} \end{subfigure} \caption{Blabla.} \label{fig:abcd} \end{figure}   Thank you for your help!


Relation between the angles of two projectiles landing in the same spot

Given that two projectiles are fired at the same velocity, from the same spot, and land at the same point following different trajectories, how can I find the difference between the two angles of projection and the times taken for the projectiles to land?  EDIT: Not a duplicate since this one involves two projectiles and two different angles rather than trying to find one unique one.


Is using DeclareMathOperator for functions the right thing to do?

I'm wondering if I use the \DeclareMathOperator for the wrong things.  For example I have a cost function cost(x,y) which takes two arguments. I would declare it as \DeclareMathOperator*{\cost}{cost} and use it later with $\cost(x,y) = ...$.  If this is correct, why do I never see the function f(...) typeset in roman? If it's not correct when should the \DeclareMathOperator* be used instead?


I'm trying to install the latest WINE, and I'm reading the readme, it's telling me to do the ./configure thing but when I do I get this message  bash: ./configure: No such file or directory   What am I supposed to do, and how do I fix it, I'm running Ubuntu 14.04, anything newer than this runs into some problems this is an old computer.


Prove determinant of $n \times n$ matrix is $(a+(n-1)b)(a-b)^{n-1}$?

Prove $\det(A)$ is $(a+(n-1)b)(a-b)^{n-1}$ where $A$ is $n \times n$ matrix with $a$'s on diagonal and all other elements $b$, off diagonal.


Why do *nix filesystems support file names with newlines?

According to :     File names in Linux can contain any characters other than (1) a forward slash ( / ), which is reserved for use as the name of the root directory (i.e., the directory that contains all other directories and files) and as a directory separator, and (2) the null character (which is used to terminate segments of text). Spaces are permitted, although they are best avoided because they can be incompatible with legacy software in some cases.   Great, both restrictions make a lot of sense. Since it is clearly possible to forbid the inclusion of certain characters in file names, why were newlines allowed? As far as I can tell their only use is to . Is there ever a valid reason to have a new line in a file name?


Is a reboot the only way to get back into the GUI after pressing "CTRL+ALT+F12"?

I just read . It was helpful, but I'm left with the question:  If you accidentally press "CTRL+ALT+F12" is the only way out of the virtual terminal to reboot the machine?  I tried every combination of (CTRL, CTRL+ALT, CTRL+SHIFT, CTRL+ALT+SHIFT, ALT, ALT+SHIFT, SHIFT) + each of the F1-12 keys to try and get back to the GUI. Nothing worked. Is the only way back into the GUI to reboot the machine?


What are some of the best missions to do on Grand Theft Auto 5 online

What are some of the best missions to do on Grand Theft Auto Online, like which missions will give you the most money/rp


Public key Issue - same key pair as existing one?

My question is a bit naive, but what if someone generates the same RSA key pair as someone else? This person would have the same private key and so would be able to decrypt messages not intended to him.   I bet that the answer will be: “It is very unlikely”, but I would like a more persuasive answer to realize that it can't happen in practice.  A related question: when someone generates a key pair, how can he/she be sure that nobody has already generated this key pair? Would the answer again be, that it is “very unlikely”?


What is the difference in below sentences between "would" and "used to"?      1) When he was free, he would go to the movies.      2) When he was free, he used to go to the movies.   And     3) When I was in 10th Std you would teach me English.      4) When I was in 10th Std you used to teach me English.


is a decomposition of galilean transforms of the form $x\mapsto Ax+y.$ Why are they all of this form?    $T$ galilean is distance preserving so it is also injective. Take $B_r(a)$ the closed $r-$ball at $a$, similarly $B_s(b)$ with $r+s=|a-b|.$ Then just as $B_r(a)\cap B_s(b)$ is singleton, their inverse-maps under $T$ must also be singleton. Varying $r,s$ holding their sum constant, one sees the inverse map of the line segment between $a$ and $b$ is another line segment. So $T$ preserves lines. But why must $T$ have the above formula?


In Rogue One, the Guardians of the Whills were mentioned. According to , they were the protectors of the ancient Temple of the Kyber.  was also known as the Temple of the Whills, or simply the Kyber temple.   Does this mean that in Disney canon "a Whill" is equivalent to "a Kyber (crystal)"? In Legends, Whills were an alien species of Force shamans, but was this changed for the current canon?


Is $\frac{\sin(x)}{x}$ continuous at $x=0$? Whats the value at $x=0$?

Is $\dfrac{\sin(x)}{x}$ at $x = 0$  continuous?  Whats the value at $x=0~?$


Asking a Question about Fonts for Web Development

I would like to ask a question about converting fonts for use on a web site.  The question will involve the existence of suitable software, as well as a question on the legality or suitability of the license.  Where is the best place to ask this?  Edit:  This is the actual question (I don’t expect it to be answered here, of course):  I would like to convert a font which uses the Open Font License to WOFF for use on a web site. My understanding is that this conversion probably contravenes the license. However, I have also read     Please note that most WOFF conversion tools and online services do not meet the two requirements listed above   —  (section 2.2)  This suggests that some tools do meet the requirements.  Can anybody suggest any software tools which meet this requirement? Preferably Open Source, and available on Linux or Macintosh.


Where is the OS X Volume Change Feedback Sound File located?

I upgraded Yosemite, and turns out they changed the "pop" sound that plays when you change the volume. I have another Mac, which is on Mavericks, and I would like to get the old sound back.  I saw , and it is NOT there in Macintosh HD ▸ System ▸ Library ▸ Sounds  Any help would be appreciated.