Find $\sum_{i=1}^{n-1}\frac{1}{2-a^i}$ if $1,a,a^2,...,a^{n-1}$ are the n$^\text{th}$ roots of unity

If $1,a,a^2,...,a^{n-1}$ are the n$^\text{th}$ roots of unity, then prove that$$\sum_{i=1}^{n-1}\frac{1}{2-a^i}=\frac{(n-2)2^{n-1}+1}{2^n-1}$$   $$ \alpha_r=e^{i\tfrac{2\pi r}{n}}=a^{r-1}\\ x^n=1\implies x^n-1=(x-1)(x-a)(x-a^2)...(x-a^{n-1})=0 $$  $$ \sum_{i=1}^{n-1}\frac{1}{2-a^i}=\frac{1}{2-a}+\frac{1}{2-a^2}+\frac{1}{2-a^3}+....+\frac{1}{2-a^{n-1}}\\ = $$ Note: This is solved using derivative of logarithm in  which is good, but I am looking for more of a direct and easier way to find the solution.


Having a bit of difficulty identifying the appropriate ARIMA model by looking at ACF/PACFs.   I know that AR(1) models, the ACF has a geometric progression from its highest value at lag 1 and the PACF has a spike at lag 1 and then then cuts off afterwards.   Could someone possibly explain how I identify the rest? AR and MA please?!?


Isn't Factory Reset exactly the same as wiping /data and /cache?

According to ,      /data ... Wiping this partition essentially performs a factory reset on your device, restoring it to the way it was when you first booted it, or the way it was after the last official or custom ROM installation. When you perform a wipe data/factory reset from recovery, it is this partition that you are wiping.   What about /boot, /system, and /recovery, and /cache?    If Factory Reset wipes only /data, then I wish it were called something else, because if you've rooted your phone, it will still be left with whatever custom ROM you flashed even after a Factory Reset.    On the other hand, if Factory Reset does indeed wipe /boot, /system, and /recovery as well, especially /boot, what does it restore those from?  Do all phones come with stock images in a real internal ROM somewhere that it can re-flash those images from?    I can somehow imagine manufacturers not wanting be burdened with the extra cost that such a spec for hardware-recoverable images might have cost them, so it got left out of the standard and left out of most phones, which is why it's so easy to brick them.  So, instead, they give you the option to wipe /data and /cache only, and call that a "Factory Reset" because you're not supposed to be foolish enough to root your phone in the first place according to their way of thinking.  Since rooting my Android and reading hundreds of posts, I've found that many of the terms I learned and accepted as a Computer Science grad student in the 80's don't quite mean the same thing anymore so I have to verify what everything really means before I do something.    Comments to  answer the first part of my question.  But they don't really answer the second part of my question which is really a complaint:  Why call it "Factory Reset" if it doesn't really restore your phone to it's stock factory state?    At this point, the question is merely rhetorical.  I think I already answered this in my question, unless someone can correct me.


I am visiting USA on a holiday next week. We would like to use a prepaid sim in our own mobile phones - Motorola G and a Samsung s4 mini. What is a recommended provider that will provide unlimited usa calls, free data up to 500mb and some talktime on international mobile phones?


What to upgrade to achieve a higher top speed?

I enjoy going fast and my current bicycle tops too early, what kind of upgrades would I need to make to achieve a taller final gear?


using **kwargs to create Class attributes

here is my beginner problem: I want to create a class with numerous attributes using a dictionary. Instead of using def init(self, att1, att2...) I'm trying to do: class Promo:     def __init__(self, **kwargs):         for k in kwargs:             self.k = kwargs[k]  passing a dictionary {att1:'xxxx', att2:'yyyy' , .....} as argument. Since I have a dozen of named arguments in each dictionary, how can I use **kwargs in my code? Thanks for you advice!! de716


Creepy user digs my old questions and downvotes them once a day

There is a creepy user who answered my question on Stack Overflow that I haven't accepted the answer with. He then keeps leaving a comment for like three consecutive days, asking for updates on his answer (which I interpret as basically asking me to accept his answer already). He also edits my old questions several times which I assume he is doing to get my attention. Well, he did.  My reputation count has been silent over the years with only occasional upvotes from old questions. Now ever since this creepy user started nagging me, my old questions suddenly gets a downvote once a day straight for a whole week now.  The thing is I've been here On Stack Overflow for 8+ years, and I've never encountered this. My silent reputation count suddenly getting downvotes along side with him nagging me makes me suspicious that it's probably his doing.  I understand that similar downvote attacks has been reported and systems are in place to detect this, but I think this creepy user could be deliberately doing it once a day at different times as to not trigger any alarms or he may even be using dummy accounts. Is there a way we can manually check on this?


\boxed math expression makes font too large when used in nested fractions or exponents

Using the \boxed environment in mathtools seems to ignore the default size considerations LaTeX makes with nested fractions: \[ \frac{\frac{1}{2}}{\boxed{\frac{1}{2}}} \]  I would like the \boxed 1/2 to be the same size as the numerator, instead, the following is produced:  How can I resolve this, preferably in a general way so that \boxed doesn't change affect the font size in any situation? EDIT: This also happens for exponents, as in the following: \[ e^x, e^{\boxed{x}} \]


How can I hide the first equation number as in the picture in latex?

How can I hide the first equation number as in the picture in latex    \documentclass{article} \begin{document} \begin{align} R=p(S\text{ working})&= p(i\text{ working}) p(S\text{ working}|i\text{ working})\\ &+ p(i\text{ faild})p(S\text{ working}|i\text{ faild}) \end{align} \end{document}


the sequence $n!+2,...,n!+n$ is made up of only composite numbers

I have found the claim that given that $n\geq2$, we have that the sequence of $n-1$ numbers $n!+2,n!+3,...,n!$ is made up of only composite numbers. Is there a proof of this? I found this pretty fascinating but I am not sure how to go around it. It seems to hold for the first few examples  $n=2$:  $S=\{4\}$  $n=3$: $S=\{8,9\}$  $n=4$: $S=\{26,27,28\}$


Why is my reputation bouncing up and down?

Please find the attached screenshot    My current reputation is 895, and the reputation tab summary also confirms it. My question is why  '905' points is displayed next to my name for some time ???  Is this a bug ? (or) If my reputation was reduced from 905 to 895 why is it not recorded in reputation tab ?  my profile link   can someone explain the behavior ?


What does the @ symbol represent in objective-c?

I'm learning objective-c and keep bumping into the @ symbol. It is used in different scenarios, for example at the start of a string or to synthesise accessor methods.   What's does the @ symbol mean in objective-c?


My web server has configuration 16 GB RAM 8vCPU (Hexcore). Apache version 2.4.  There will be massive site visit. So what will be the best and recommended Apache tuning configuration ? I am using worker MPM.  My current configuration:  <IfModule mpm_worker_module>     ServerLimit             550     StartServers             8     MinSpareThreads          90     MaxSpareThreads         350     ThreadLimit              80     ThreadsPerChild          64     MaxRequestWorkers        512     #MaxClients             448     MaxRequestsPerChild   10000 </IfModule>   Hoping for you quick and genuine response. :-)


I'm thinking of extracting the "best" parts of my home video files. Why? Because my videos has a lot uninteresting footage that I don't need wasting disk space.  I thought I'd use -ss and -t to specify the part I want, and -codec copy. Example:   ffmpeg -i iphone4sFullVideo.mov -ss 00:00:10 -t 10 -codec copy iphone4sGoodPart.mp4   I have of course tested this and know this creates a new file with a length of 10 seconds that plays in vlc.  With doing this I think I am getting no loss in quality, and being able to use the mp4-video in a GUI video editor (like Adobe Premiere Elements) later. I was planning to do this with my video files from different phones and camcorders. I got .mts, .mov and .mp4.   My question is kind of advice seeking. Is what I'm thinking of stupid? Will my files be ok after copying a part to an mp4 container?


Suppose that a set has an odd number of elements. Explain why half of the subsets will have an odd number of elements .  Now assuming set A is the set with an odd number of integer elements{1,2,3,4,5}  Subset b ={1,2}  subset c={3}  Subset d={4,5}  Now there are two subsets with even number of elements and one subset with an odd number of elements.It seems to contradict the earlier theorem that i have to prove.I think that i am missing something.


Problem:   Prove that a set of nine consecutive integers cannot be partitioned into two subsets with same product   My attempt:  This problem would be solved if it could be proven that 9 consecutive numbers cannot exist such that all the numbers are of the form $2^a  3^b  5^c  7^d$ where $a,b,c,d$ are integers.  A suitable hint would be appreciated, I don not want a complete solution.  Edit:  If there existed a prime factor greater than $7$ of any number present in the set, then its multiple cannot exist b/c $22-11>9$  Edit 2: As mentioned by Erick, my reasoning is not valid for numbers $1-9$ and $2-9$, let this be an exception.


So I took an introductory abstract algebra course a few semesters ago, and we were shown that groups and rings can both be made into products, i.e. if I have some group $G$ (resp. ring $R$) and some indexing set $I$, then I can make a group $G^{I}$ (resp. ring $R^{I}$) with the appropriate cardinality. However, it was also demonstrated that for fields, you cannot keep the multiplicative inverse under a product structure, i.e. if I have fields $F_{1}, F_{2}$, then $F_{1} \times F_{2}$ will still be a ring, but you will not (not just "not in general", but won't) have multiplicative inverses for all non-zero (i.e. not $(0, 0)$) elements, as you could pick $(0, x)$, where $x \neq 0$. According to Wikipedia, an ultraproduct will preserve field structure, but I'm not sure what the cardinality of $\prod_{i \in I} F_{i} / \mathscr{U}$ would be in general.  I saw  that said you could make a field of arbitrarily large cardinality by extending a given field through throwing in a whole bunch of "transcendental" elements. The example given was that if I had $\mathbb{Q}$, I could start by dumping in the complexes, but then I suppose after that I'd just start throwing in dogs and cats or something; I'm really not sure what that responder meant, and ceteris paribus, my dogs tend to stay inside, so I'd rather keep them out of my fields, particularly the large ones the thread was interested in.  Moreover, the thread mentioned earlier seemed more concerned with just making the fields big. My question is a bit more nuanced: Given any cardinality $\kappa > 1$, can I generally construct a field $F$ of a cardinality $\kappa$? Moreover, how vague do I have to be about it (i.e. do I have to use some really choicy methods, or can I make it a bit more straightforward)?  Thanks.  EDIT: Sorry. I am aware that for finite fields, you are limited to powers of primes. I meant for infinite cardinals.


I'm working on a piece of server software. Usually it runs with RSS ~250 megabytes, but occasionally gets killed by the OOM, and looking at kernel log, it happens when the RSS grows to about 700 megabytes. I understand that it's not possible to get the kernel to generate a core dump when it handles an OOM. Are there perhaps other ways to get a core dump? One thing I tried was to set MemoryMax=500M in the server's systemd unit file, hoping that this would trigger before the kernel OOM and hopefully produce a core dump. Regrettably, this does not seem to be the case. I also tried adding special code to the server itself, a loop to check its total memory allocation and report that (to begin with), but doesn't seem to trigger. This check runs every 15 seconds (at the moment), probably means that when memory usage balloons, it happens quite fast. The server is written in Go, at this time it has about a thousand coroutines doing stuff, so I really need to debug with a coredump. Without a coredump, I'm blind. The OS is Debian 10.6 with systemd-coredump installed and enabled, 64 bit, running on a VPS. Any suggestions?


How much effect does having information from more than 4 satellite increase the accuracy of a 3D fix

I know that a GPS receiver requires at least 4 satellites to locate its position in 3D, and I have read elsewhere that having more than 4 satellites would increase its location accuracy. My question is is there a way to calculate how much of a reduction in error is gained due to the increased number of satellites?


Let $x$ be a whole number. Show that $x(x-1)(x+1)$ divided by $6$ is a whole number.

Proving things in mathematics is very difficult for me. I don't quite understand what to do here:  Let $x$ be a whole number Show that $x(x-1)(x+1)$ divided by 6 is a whole number  I really appreciate any help


Prove that $p_{AB}(\lambda) = p_{BA}(\lambda)$

Characteristic polynomial of square matrix $A \in \mathbb{R}^{n \times n}$ is defined like this $p_{A}(\lambda) = \det(\lambda I - A)$. I have to prove the following:  $$p_{AB}(\lambda) = p_{BA}(\lambda)$$  I know that it's easy to prove if just one of $A$ or $B$ is non-singular by using $AB = A^{-1}(AB)A$ and $p_{PAP^{-1}}(\lambda) = p_{A}$.   But I struggle to prove it for the case of both matrices being singular. I am trying to compare coefficients of $\lambda^i$ from both sides. And I see that it's true for $\lambda^n$, $\lambda^0$ and $\lambda^{n-1}$ since the coefficients for them are $1$, $(-1)^n \det(AB)$ or $(-1)^n \det(BA)$ which is the same and $-trAB$ or $-trBA$ which is also the same.  But for any $\lambda^i$ the formula of coefficient is $(-1)^{n-k} (\sum _{i_1<i_2...<i_k} \det R_{i_1,i_2,...,i_k})$ where $R_{i_1,i_2,...,i_k}$ is $AB$ or $BA$ with crossed $i_1,...,i_k$ rows and columns.  I'd like to add that I am just at the beginning of studying linear algebra so I'am not aware of fields, ranks or any concept past determinants.


How to automatically typeset a table in three columns?

With the following, I can get a table in "two columns" - it is possible to make it three? It is possible by splitting the whole table by human hand, but there should be some automatic solutions. \documentclass[twocolumn]{article} \usepackage{xtab,booktabs} \usepackage[textheight=10cm]{geometry}   %% just for this example.   \begin{document} \topcaption{This is top caption} \bottomcaption{This is bottom caption} \tablecaption{this is table caption} \tablefirsthead{\toprule First&\multicolumn{1}{c}{Name} \\ \midrule} % \tablehead{% \multicolumn{2}{c}% {{\bfseries  Continued from previous column}} \\ \toprule First&\multicolumn{1}{c}{Name}\\ \midrule} % \tabletail{% \midrule \multicolumn{2}{r}{{Continued on next column}} \\ \midrule} \tablelasttail{% \\\midrule \multicolumn{2}{r}{{Concluded}} \\ \bottomrule} \begin{xtabular}{ll}     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text comes\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text\\     content & some text comes here too \\     content & some text\\     content & some text\\     content & some text\\     content & some text \end{xtabular}% \end{document}


Proving $2$ generates $(\mathbb{Z}/19\mathbb{Z})^*$ by only looking at a few powers

So I'm first asked to compute, mod 19, the powers of 2,   $$2^{2},2^{3},2^{6},2^{9}$$  which I compute as   $$4,8,7,18$$  respectively.    I'm then asked to prove that 2 generates $(\mathbb{Z}/19\mathbb{Z})^{*}$ based on the above.  I'm not seeing how you can only look at these powers to know that 2 generates the group.  Of course I could compute the rest of the powers of 2 and show that all $1\leq a\leq 18$ are congruent to $2^{k}$ for some integer $k$, but I get the impression that this is not what I'm supposed to be seeing here.  What I am noticing is that I've basically computed $2^{2}$ and $2^{3}$ and then a few combinations of them.  Trivially I can get $1$ as $2^{0}$ and 2 likewise, and I'm allowed to take negative integer powers so I must get $2^{-1}$.  If I somehow knew that $2^{-1}$ were not $4, 8, 7,$ or $18$ then that would be nice, but I don't see how I can be assured of that without explicit calculation--and I get the feeling this is supposed to be an exercise in not explicitly calculating these.  Maybe this is supposed to be "half calculation", like showing that because I can get $4\cdot 8=32$ and $4\cdot 7=28$ I must therefore be able to obtain ... I don't know what.  Any hints?  Or am I over-thinking this and I should just calculate every power of 2?


Does convergence in $L^p$ imply convergence almost everywhere?

If I know $\| f_n - f \|_{L^p(\mathbb{R})} \to 0$ as $n \to \infty$, do I know that $\lim_{n \to \infty}f_n(x) = f(x)$ for almost every $x$?


Positive integer solution such that $7^m - 3^m$ is prime

Find all $m \in \mathbb{Z}$, for which the expression $7^m - 3^m$ a prime. What would be the general strategy for solving this? I have no clue where to begin. I tried picking $m$ and checking some values but I don't see any relation between them. This question can be solved using modular arithmetic as well but im not sure how. What I do know is that $7^m - 3^m > 1$.


I have this flash drive that I grabbed from work that has a few files on it I would like to delete.   It is a 32GB flash drive and when trying to delete the data I get this error message:     "This Drive is write protected."   Is there a way to change this on a Mac? I have tried erasing the drive and get this error.     Here is all the information about this Drive. Any ideas?    I have tried changing this on a Windows as well by going into regedit and changing the WriteDefault to 0, I had to actually create that 32-WRD key because there was none initially. I restarted the computer and no luck. I also tried going into Command Prompt and clearing the partitions on it with no luck either.


Why can't I see keyframes in the timeline?

I was doing some animation, when I didn't know how to animate using edit mode. Someone showed me a tutorial on YouTube by using hooks. It managed to work, but then I began to realise that the keyframes were not showing AT ALL in the timeline , despite clicking on the selected object with the auto-keying. Have I done something wrong?


Idiom for someone who got a tiny fraction of power and abuses it?

Is there any idiom for a person who somehow obtained a (usually small) power to control people and is using it in every possible way to make problems for people around him?


Determining application path in a Python EXE generated by pyInstaller

I have an application that resides in a single .py file.  I've been able to get pyInstaller to bundle it successfully into an EXE for Windows.  The problem is, the application requires a .cfg file that always sits directly beside the application in the same directory.  Normally, I build the path using the following code:  import os config_name = 'myapp.cfg' config_path = os.path.join(sys.path[0], config_name)   However, it seems the sys.path is blank when its called from an EXE generated by pyInstaller.  This same behaviour occurs when you run the python interactive command line and try to fetch sys.path[0].  Is there a more concrete way of getting the path of the currently running application so that I can find files that are relative to it?


How can I pass *args from one function directly into another one called within it and maintain its functionality?  If I do it like this:  def parent(*args):     child(args)  def child(*args):     print(args)   I get this output:  >>> parent(1, 2, 3, 4) >>> ((1, 2, 3, 4),)   but:  >>> child(1, 2, 3, 4) >>> (1, 2, 3, 4)   I want the parent function to print out the same as if I called the child function directly.  Thanks!


Show that the sequence $a_n\leq a_{2n}+a_{2n+1}$ diverges

We are given a sequence $(a_n)$ such that $0\lt a_n\leq a_{2n}+a_{2n+1}$ for all natural numbers $n$. Show that $\sum_{n=1}^\infty a_n$ diverges.    I attempted the question as follows. Consider, say, $$\begin{align} S_7 &=  a_1+(a_2+a_3)+(a_4+a_5)+(a_6+a_7)\\   &\geq a_1+a_1+(a_2+a_3)\\   &\geq a_1+a_1+a_1 \end{align}$$  But I have no idea how to generalise this to show that the sequence diverges.


What is the difference between ionisation enthalpy and work function?

The energy required to remove an electron from the surface of a metal is less than that required to remove an electron from a free atom. Why?The electron is bound to the nucleus in an atom by electrostatic forces. How is an electron 'free' on a metal surface?


Can I "map" or define a record on a file?

In the olden days of DEC/HP VMS Vax Basic, there was a way to define a record's fields and "map" that definition to an open file. When a record was read, the fields defined in the map were populated for that record without coding the parsing and setting. It used to look like this:  MAP (Bec) STRING Owner = 30%, LONG Vehicle_number,    &           STRING Serial_number = 22% OPEN "VEH.IDN" FOR INPUT AS FILE #2%,                 &       ORGANIZATION SEQUENTIAL FIXED,                  &       MAP Bec, ACCESS READ INPUT "Which record do you want";A% WHILE (A% <> 0%)    GET #2%, RECORD A%    PRINT "The vehicle number is", Vehicle_number    PRINT "The serial number is", Serial_number    PRINT "The owner of vehicle";Vehicle_number; "is", Owner    INPUT "Next Record";A% NEXT CLOSE #2% END   I cannot find if there is anything similar in a .Net environment, specifically C#.


Mongodb: Possible to enlarge a capped collection?

If a collection is created as capped, is it possible to increase the cap without losing data?  Or to increase the cap without recreating the whole collection?  Thanks


Meta Stack Overflow needs a Meta Meta Stack Overflow

Meta Stack Overflow has gotten a bit (well, not just a bit) out of hand, what with all of the ponies, the perfect freehand circle obsessions, the parakeets, the haikus, the ponies, the circle and the haikus, and that's only half of the problem.  I'm not suggesting anything at all similar to , since I seriously want to be able to talk about how weird Meta Stack Overflow really is.   My only hope is that MMSO will not get as screwy as MSO is right now, since then we'd be on our way to an infinite (or rather, 411 time) recursion, unless we can define a base case of some sort.  Any ideas? And please no ponies.


Equation exceeds single column of IEEE template

The equation is attached here.  \begin{multline}\label{eq6} MI\left( {E,{E^t},E_k^n,E_l^m} \right) =  \sum\limits_i {\sum\limits_j {p\left( {{E_i=0},E_j^t=0,E_k^n=0,E_l^m=0} \right) {{\log }_2}\left(  {\frac{{p\left( {{E_i=0},E_j^t=0,E_k^n=0,E_l^m=0} \right)}} {{p\left( {{E_i=0}} \right)p\left( {E_j^t=0} \right)   p\left( {E_k^n=0} \right)p\left( {E_l^m=0} \right)}}} \right)} } +{p\left( {{E_i} = 0,E_j^t = 0,E_k^n = 0,E_l^m = 1} \right) {{\log }_2}\left(  {\frac{{p\left( {{E_i} = 0,E_j^t = 0,E_k^n = 0,E_l^m = 1} \right)}} {{p\left( {{E_i} = 0} \right)p\left( {E_j^t = 0} \right)   p\left( {E_k^n = 0} \right)p\left( {E_l^m = 1} \right)}}} \right)} \end{multline}


Get the generated SQL statement from a SqlCommand object?

I have the following code:  Using cmd As SqlCommand = Connection.CreateCommand     cmd.CommandText = "UPDATE someTable SET Value = @Value"     cmd.CommandText &= " WHERE Id = @Id"     cmd.Parameters.AddWithValue("@Id", 1234)     cmd.Parameters.AddWithValue("@Value", "myValue")     cmd.ExecuteNonQuery End Using   I wonder if there is any way to get the final SQL statment as a String, which should look like this:  UPDATE someTable SET Value = "myValue" WHERE Id = 1234   If anyone wonders why I would do this:   for logging (failed) statements for having the possibility to copy & paste it to the Enterprise Manager for testing purposes


Ubuntu 16.04 WIFI not working after install

I have tried installing 'additional drivers' and going through several of the posts on the forum looking for a solution.  However, I cannot figure it out.  Can someone please help me get my wifi working?  lspci -knn | grep Net -A2 08:00.0 Network controller [0280]: Broadcom Limited BCM4352 802.11ac Wireless Network Adapter [14e4:43b1] (rev 03)     Subsystem: Lenovo BCM4352 802.11ac Wireless Network Adapter [17aa:0623]     Kernel driver in use: bcma-pci-bridge     Kernel modules: bcma, wl   And then  sudo lshw -C network   *-network                       description: Network controller        product: BCM4352 802.11ac Wireless Network Adapter        vendor: Broadcom Limited        physical id: 0        bus info: pci@0000:08:00.0        version: 03        width: 64 bits        clock: 33MHz        capabilities: pm msi pciexpress bus_master cap_list        configuration: driver=bcma-pci-bridge latency=0        resources: irq:17 memory:d1600000-d1607fff memory:d1400000-d15fffff   *-network        description: Ethernet interface        product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller        vendor: Realtek Semiconductor Co., Ltd.        physical id: 0        bus info: pci@0000:09:00.0        logical name: enp9s0        version: 10        serial: f0:76:1c:5b:c8:2d        size: 1Gbit/s        capacity: 1Gbit/s        width: 64 bits        clock: 33MHz        capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation        configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=rtl8168g-3_0.0.1 04/23/13 ip=192.168.1.90 latency=0 link=yes multicast=yes port=MII speed=1Gbit/s        resources: irq:30 ioport:3000(size=256) memory:d1804000-d1804fff memory:d1800000-d1803fff


JQuery $(this) not recognized after HTML is modified

I have a website consisting a few href links and 2 buttons that can change what those links are.

Classical Mechanics

Position, Velocity, Acceleration

Newton's Laws

Friction

Choose Dificulty:         <button type=“button" onclick=“beginerButtonAction(this)">Beginer</button>         <button type=“button" onclick="intermediateButtonAction(this)">Intermediate</button>

   After the original html is loaded, when links are clicked, the alert function in the javascript file is triggered.   $(function(){   $(".topic_link").click(function(){     alert($(this).text());   }); });   And everything works fine.  The problem arises after the buttons are pressed and the href are changed.  function beginerButtonAction(id) {      $( "div.links" ).remove();      var newLinks;         newLinks= '
'+          '
Classical Mechanics
'+               '
'+                 '
Moment of Inertia
'+               '
'+            '

'+               '
'+                 '
Drag Force
'+                   '
'+       '
';      var $jNewLinks = $(newLinks);     $("body").append($jNewLinks); }  function intermediateButtonAction(id) {      $( "div.links" ).remove();      var newLinks;         newLinks= '
'+          '
Classical Mechanics
'+               '
'+                 '
Torque
'+               '
'+            '

'+               '
'+                 '
Momentum
'+                   '
'+       '
';      var $jNewLinks = $(newLinks);     $("body").append($jNewLinks); }   After the html is modified the href no longer triggers the alert.  I want the alert to fire after html is changed. Any thoughts?


Can a 4th level or higher Dispel Magic dispel the effects of a Duration: Instantaneous spell?

When cast at 3rd level, dispel magic ends a spell that is currently affecting the target:  Choose one creature, object, or magical effect within range. Any spell of 3rd level or lower on the target ends. For each spell of 4th level or higher on the target, make an ability check using your spellcasting ability. The DC equals 10 + the spell's level. On a successful check, the spell ends.  Notably, this does not work on effects from spells with instantaneous duration, as those spells have already ended. But when cast at 4th level or higher, it appears as though it should end spell effects from spells having Instantaneous duration:  When you cast this spell using a spell slot of 4th level or higher, you automatically end the effects of a spell on the target if the spell's level is equal to or less than the level of the spell slot you used.  Is this the correct ruling? Does a 4th level dispel magic end spell effects from instantaneous duration spells?


I'm from Russia and I've got a problem with writing a letter. Can I use the phrase "glad to hear such news" if I'm not speaking with a person? Isn't it better and more correct to use "glad to know"?


The probability that no person has the same birthday month

If there are $12$ people in the room what the chances are that no two people will have the same birthday month?   I tried to think of it in this way:  The total number of options is $12^{12}$  The option that no one will have the same birthday month is:  $12 * 11 * ... 1$ which means $12!$  So I think the answer is:  $$\frac{12!}{12^{12}}=0.0000537$$  What do you think?   Thank you!


I am just starting with WSL2, installed everything as per:  Ran the Ubuntu 18.04 in my windows, everything looked good. I tried to access the rootfs from LocalState, but found an ext4 VHD instead. I double clicked on it, and my Ubuntu, stopped working. Got an error like "This file is currently being used". Figured it could be because VHD was mounted or something, restarted the system. Now I get the following error instead: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. I have made the Hypervisor launch as automatic using: bcdedit /set hypervisorlaunchtype auto I dont know why I am getting the error. Any workarounds ? Or should I reinstall Ubuntu or something ?


What is a better explanation for why $\sum\limits_{n=2}^{\infty}\frac1{n\ln(n)^{1.01}}$ converges?

So I want to show that $$\sum_{n=2}^{\infty}\displaystyle\frac{1}{n\ln(n)^{1.01}}$$ converges.  I suppose if $$\ln(n)>n^{0.01}$$then $$n\ln(n)>n^{1.01}$$ and so $$\displaystyle\frac{1}{n\ln(n)^{1.01}}<\displaystyle\frac{1}{n^{1.01}},$$ meaning that   $$\int\limits_{2}^{\infty}\displaystyle\frac{1}{n\ln(n)^{1.01}}\mathrm dn<\int\limits_{2}^{\infty}\displaystyle\frac{1}{n^{1.01}}\mathrm dn.$$   And since the RHS of the inequality converges by the $p$ test, the right hand term also converges, and so the series converges. Is this correct? If it is, is there a better (e.g. more straightforward/obvious/elegant...etc.) way of showing that the series converges?


Would one say "...a vendor who..." or "...a vendor that..."?

What is the correct way to form a relative clause after the word "vendor" in the following sentence?   Our machines are serviced by a third party vendor who checks the machine during regular service.  Our machines are serviced by a third party vendor that checks the machine during regular service.


I’m trying to add Products to my OrderLine (which is held by an Order) but when I try I get the NullPointerException.  import java.util.*; public class OrderLine;  private HashMap<Integer, Integer> products = new HashMap<Integer, Integer>();  //setter and getter for products  public void add(int productNbr, int amount) {     int newAmount = this.products.get(productNbr) + amount;     this.products.put(productNbr, newAmount); }   And my Main-tester;  public class Main {  public static void main(String[] args) {  OrderLine ol = new OrderLine(); ol.add(1, 661); ol.add(1, 5); //key 1 should hold value 666 System.out.println(ol.getProducts()); //Should print out {1, 666}   But all I get is "Exception in thread "main" java.lang.NullPointerException".  I get the feeling that it works if I define/initiate the value before I add anything to it, but I shouldn't have to do that every time. Any ideas?  UPDATE: Fixed version;  public void add(int productNbr, int amount) {     if (this.products.get(productNbr) != null) {         int newAmount = this.products.get(productNbr) + amount;         this.products.put(productNbr, newAmount);     } else {         this.products.put(productNbr, amount);     } }


How to change the refresh rate at which the network manager updates the wireless access points

Sometimes it takes too long for the network manager to update to see new wireless AP. Is it possible to change the time interval between checks?


What is the Taylor series representation of $f(x) = \sqrt{x}$ about $c = 1$ without use of double factorial?

Hey all I know this question has been asked before, but the other thread has not answered the question I am looking for. I think I found a series representation of $f(x) = \sqrt{x}$, but it uses the double factorial $$1 + \frac{1}{2}(x-1)+\sum_{n=2}^{\infty}(-1)^{n-1}\frac{(2n-3)!!(x-1)^n}{2^nn!}$$  I am fairly sure this representation is correct, but my professor has never introduced us to double factorials so I have a feeling this is not the way he wants us to approach this problem. I have been introduced to binomial series and I feel that might be a better representation, but I am still unsure how to write it as a binomial series, any pointers? Thanks!


Does a Fighter's Action Surge stack with the Haste action?

A fighter, once per rest, can use Action Surge to gain an additional action on his turn.  The target of a Haste spell also gains an additional action on his turns (until the spell ends).  If a fighter is Hasted by a fellow mage and then uses his Action Surge, does he gain two additional actions on his turn (for a total of 3 actions, plus the eventual bonus action & reaction) ?


How to close on screen keyboard from menu bar option “A” near the spotlight search via applescript for mojave, sierra, high sierra, el capitan

I got one solution for the same question previously. But i am facing problem with other mac os. Something which will work on Big Sur, Catalina, Mojave, Sierra, High Sierra and El Capitan. At least for Mojave for now. This is solution I got from this link and it worked in Catalina and Big Sur as I told him only for Catalina and Big Sur:  Its just I am looking for something which will be working even in Mojave, Sierra, High Sierra and El Capitan.


Are temporary hit points counted when considering total damage?

For some damage like a vampire's bite attack or the  spell, your maximum HP is reduced based on the damage taken. What happens if some or all of that damage is absorbed by the target's temporary hit points? Does that count as damage taken or not?


Proving trigonometric equation $\cos(36^\circ) - \cos(72^\circ) = 1/2$

Please help me to prove this trigonometric equation.  $\cos \left( 36^\circ \right)-\cos \left( 72^\circ \right) = \frac{1}{2}$  Thank you.


I'm trying to get my head around modules, and there's a problem that's bothering me regarding scalar multiplication from the left vs from the right.  In many books/articles I've read, the author may refer to a left $R$-module $M$, and then continue to talk of terms such as $xr$, where $x\in M$, $r\in R$. What is right scalar multiplication in a left module? Does it even make sense to talk about it?  I've been trying to show that over a commutative ring, right scalar multiplication and left scalar multiplication are the same thing, but I've not managed it so far. I've googled it to no avail, and I can't see why the distinction between left and right modules disappears when the base ring is commutative.  Thanks for any replies!


Without a map or miniatures, how to best determine line-of-sight, etc?

I think the title says it all. Let's say you're mastering a game without the benefit of miniatures, maps, or any kind of physical representation of the environment. How would you keep track of details like line-of-sight, ranged attack viability, and all the other small nuances which go with creating a "believable-enough" environment in which your PCs live and thrive?  (I admit that @LoganMacRae, who is my own DM, is an inspiration for this question. He does this with panache, and in my one-off, I feel like I have some mighty big shoes to fill!)


How to create an infinite plane in cycles?

I have already found one similar , however it doesn't correctly address what I am talking about. Please see , example to know exactly what I'm talking about. I have only found , and , but both use a curved plane to do the trick, which would work unless the object is to be rotated(in animation) to view from every angle.      Yes, again we could rotate the object instead of the camera but, what about a large array of object, that would really distort the scene and setting the camera accordingly would be very difficult.    Setting the camera at this angle would be good even for a large array of objects: , but what if we need a more acute view like this:  , (even if we set the world background color to white this would be impossible to actually blend if taking the lighting into account, as it would emit light and the edges of planes would be visible.)    I don't know if there is a workaround with the lightpath node with this to only make the area where the shadow falls visible. And I don't know how to take only the shadow information into the compositor to make this?    Primarily focusing two problems: 1) how to make such a world in cycles, infinite, only the shadow information and the object? 2) How to make such a world in cycles, infinite, only the shadow information and the object and a slight gradient in the infinite world?  Therefore, I resolved here.


How to call two function from "action" attribute of command button

I have two function which needs to be called from one button. Currently I am doing this by creating two button one "Confirm" and another "Save". but I don't want two button I want only one button "Save", on click of Save first the method called by "Confirm" button should be called and then the method called by "Save" button.  Below is my code:  <apex:commandButton value="Confirm" action="{!save}"/>    <apex:commandButton value="Save" action="javascript:top.window.opener.closeFunction()" ></apex:commandbutton>


What does free -m shows and how to explain it?

My free -m  free -m               total        used        free      shared  buff/cache   available Mem:           7971        1834        2878          79        3257        5713 Swap:          8179           0        8179   What is Mem and what is Swap?


How to insert a listing inside a definition in LyX

My problem is that when I want to insert a list after having inserted a definition, LyX seems to end the \begin{defn} block and start the \begin{itemize} block. What I want is to have the \begin{itemize} block inside the \begin{defn} one. How can I do this whithout having to modify tex code?


Ubuntu 20.04 Network Performance Extremely Slow

I just upgraded from Ubuntu 18.04 to 20.04 on one of the  machines, and the network performance is abhorrent. Internet speed is very fast from a google speed test (>300Mb/s for both upload and download).     However, whenever I try to browse a website or even run sudo apt update the connection will often time out. My internet is very fast on all other devices and I really don't know how to debug this problem.  sudo lshw -class network -short && nmcli device status    shows  H/W path           Device           Class          Description ============================================================== /0/100/1c.6/0      wlp2s0           network        Wi-Fi 6 AX200 /3                 br-96f5b790e29e  network        Ethernet interface /4                 br-15e76fb81c05  network        Ethernet interface /5                 docker0          network        Ethernet interface  DEVICE           TYPE      STATE         CONNECTION       wlp2s0           wifi      connected     CSA HQ           br-15e76fb81c05  bridge    connected     br-15e76fb81c05  br-96f5b790e29e  bridge    connected     br-96f5b790e29e  docker0          bridge    connected     docker0          p2p-dev-wlp2s0   wifi-p2p  disconnected  --               lo               loopback  unmanaged     --               gpd0             tun       unmanaged     --                Solution:  It seems like this is a pretty common problem, and one without a definitive cause. For me, it was because Ubuntu resets the TLP configuration, and the power management went back to "on". I disabled Wi-Fi power management directly by editing:  sudo nano /etc/NetworkManager/conf.d/default-wifi-powersave-on.conf   Then changed the value from 3 to 2, saved changes and rebooted.  I actually got this solution from Reddit and this worked for my case specifically but it seems like it could be caused by a bunch of other things. Read all the proposed solutions below!


Add a segment that will always stay in Google Analytics' "Audience overview"

If you go in Google Analytics' Audience overview, you can Add segment:    Once done, click "Save". The new segment is now displayed:    Now close the browser, and open the browser again, Audience overview: the segment is no more there! You have to do Add segment once again manually!  How to add a segment once for all that will stay in Google Analytics' Audience overview?


On   while browsing Meta Stack Overflow, I have encountered the phrase information porn, typically used by Jeff Atwood. What does it mean?


Merging attributes from point with containing polygon?

I need to develop a process for merging the attributes of each point in a SDE feature class with a polygon in a SDE feature class that contains the point to create a third feature class. The third feature class should contain the attributes of the point with the geometry of the polygon. This seems to be a spatial join. Is that assumption correct?  The points represent incident locations. The polygons represent counties. The team is requesting I intersect the incident with the county to create the third feature class. There will be multiple incidents per county so they expect to see a row for each incident and the county geometry will be repeated.  I've been using ArcToolbox > Analysis Tools > Overlay > Spatial Join. Setting the Target Feature to the incidents layer and the Join Features to the counties layer yields the correct number of rows but the geometry is a point. I need a polygon. Switching the Target Feature and Join Features yields the correct geometry but not the correct number of rows.  How should I be approaching this?


Which word can be used for the person who is challenged (in a contest)?

The words "challenge" and "challenger" are well-known, but is there such a term as "challengee" - as I read somewhere? In other words, what would be an appropriate term to describe the person challenged, for instance, to play a challenge match? Unsure whether to ask for the "antonym" of challenger.


How do you find a square matrix $X$ from an equation of the type  $AX = XB$?  ($A$ and $B$ are known square matrices)  How do I scale the solution up to multiple $A$s and $B$s for a single unknown $X$, i.e.  $\forall_{i=1...n} A_i X=XB_i$  Besides finding a solution, I would like to know what the problem is called. I am sure it pops up in lots of different research areas, and must have been solved before, but I don't know what exactly to ask Uncle Google.  Thanks you all in advance.


App can't be moved to SD Card , Option not available

I've installed a app called PyDroid 3 from Play Store, but  I don't have much space available on my internal memory so i wanted to move the app to SD Card. But Move To SD Card option is available on this app.  Using Android 5.1 on Samsung J2


Are Stack Exchange 1.0 Sites still available for creation?

Can you still get the software to make a 1.0 site in return for a payment? I would assume they remove the method after switching to 2.0. But I was wondering if it's still a method that is an alternative to Area 51.


Let $f:[0,1] \rightarrow \mathbb{R}$ be continuous. Show that $\int_{0}^{1} x^n f(x)dx \rightarrow 0$

Idea: I thought of using the Mean value theorem for integrals   It says that if $f:[a,b] \rightarrow \mathbb{R}$ and $g:[a,b] \rightarrow \mathbb{R}$ are two integrable functions, and if $g(x)$ does not change sign on $[a,b]$.  Then $\int_{a}^{b} f(x)g(x) dx = \alpha\int_{a}^{b}g(x)dx$ where $m \le \alpha \le M$ .  Now take $g(x) = x^n$ and the above problem reduces to $\lim_{n \rightarrow \infty} \alpha\int_{0}^{1}x^ndx$.  Now if we evaluate $\int_{0}^{1}x^ndx$ we get $\frac{1}{n+1}$ which whe $\lim_{n \rightarrow \infty}$ is taken gives $0$.  Is the approach correct?  Can the integral be evaluated before taking the limit?


How did Odin know about the Infinity Gauntlet?

In Thor, there is a scene where you can see what looks like the Infinity Gauntlet in Odin's vault. Later (in Avengers: Age of Ultron, IIRC) you learn that Thanos actually has the Infinity Gauntlet, raising some questions about the one in Odin's vault, which are answered in Thor: Ragnarok when Hela sees it in the vault, knocks it over, and proclaims it to be a fake.  After all this, Kevin Feige  how the Gauntlet in Odin's vault was originally mostly just an easter egg, but also gave an in-universe explanation for Odin having a fake Infinity Gauntlet; essentially that Odin was pretending to have it so people on Asgard wouldn't worry about it being used against them.  However, in Infinity War, Eitri tells Thor how Thanos came to Nidavellir and forced him to make the Infinity Gauntlet, then killed everyone and chopped off Eitri's hands, putting an end to everything there. It seems that no one was aware that Nidavellir was shut down or that any of this had happened, and seeing as how the Gauntlet was made for -- and went directly to -- Thanos, how did Odin come to know that it even existed and get details of what it looked like in order to create a fake for his vault?


Can I omit the "neither" in a neither/nor construction?

Considering this sentence:     Something was awry but neither Alice nor Bob knew what.   Can I omit the neither here?     Something was awry but Alice nor Bob knew what.   It sounds reasonable, but I found it strange that it requires a list to make this negation work.  When it's just Alice, more words are required to express negation:     Something was awry but Alice did not know what.


Does mixing alcoholic drinks really make you more drunk?

There is plenty of anecdotal evidence ("beer after wine and you'll feel fine, wine after beer will make you feel queer") that mixing alcoholic drink types leads to a stronger effect, but I can't find any true studies.   In fact the only studies I found are looking at mixing energy drinks and alcohol (mixing with energy drinks increases motivation for more alcohol (in college students) []), and discussed mixing caffeinated beverages with alcoholic ones [].  Are there any studies specifically looking at mixing alcoholic drinks? They would have to compare people drinking the same amount of alcohol, but some people mixing, others drinking the same thing. Maybe even a cross-over study design? Same people do both, one after the other? The only way to get an unclouded answer!  I am also interested in the follow-up why question: Why does mixing some drinks make you more drunk? Presumably it is something in wine (for example) that interacts badly with something in beer at the chemical level (the metabolites maybe)?   Marczinski CA, et al, (2012). Mixing an Energy Drink with an Alcoholic Beverage Increases Motivation for More Alcohol in College Students. Alcohol Clin Exp Res, epub. doi:  Touyz LZ, (2011). Mixing drinks and concocting troubles. Curr Oncology, 18(6):262-3. ; .


Code after for loop does not execute (Java)

I have a small snippet of code that is supposed to check the inputted codename and password against what is stored in a text file. If there is a match, it will start the game and everything is fine. But if there is no match, a dialog is supposed to pop up asking the user if they want to try logging in again.   int input=0; //yes  do {     codename=JOptionPane.showInputDialog(null,"Enter Codename: ");     String password=JOptionPane.showInputDialog(null, "Enter Password: ");      for(int i=0;i<users.length;i++){         if((codename.equals(users[i].getCodeName())) && (password.equals(users[i].getPassword()))){             System.out.println("\n\nCorrect");             new Game();         } else {             System.out.println("\n\nIncorrect");         }        }     input = JOptionPane.showConfirmDialog(null, "Incorrect User name/Password\nWould you like to try again?");           } while(input==0); //run while input is yes   The problem: the code after the for loop does not execute. If I check the variables against users[i] the code after the for loop does not run, but if I check against users[2] for example, then it works fine.  Not sure if this matters but I always get this error:   Exception in thread "main" java.lang.NullPointerException     at com.ramtin.Game.logOn(Game.java:505)     at com.ramtin.Game.main(Game.java:397)   I get it even when the password and codename match and the program runs perfectly.  FULL CODE for the above code:      public static void logOn(){         //ASK FOR CODENAME & PASSWORD FROM TEXTFILE BEFORE GAME BEGINS         //read from text file          UserData[]users=new UserData[20];         int countU=0;          try{             BufferedReader readU = new BufferedReader(new FileReader("userdata.txt"));              String line;              while((line=readU.readLine())!=null){                 String []parts=line.split("#");                  String codeName = parts[0];                 String password=parts[1];                  //              System.out.println(parts[0]);                 //              System.out.println(parts[1]);                 users[countU]=new UserData(codeName, password);                 countU++;             }             readU.close();         }         catch(FileNotFoundException e){          }         catch(IOException e){          }          //PASSWORD & CODENAME          int input=0; //yes          do{             codename=JOptionPane.showInputDialog(null,"Enter Codename: ");             String password=JOptionPane.showInputDialog(null, "Enter Password: ");              for(int i=0;i<users.length;i++){                 if((codename.equals(users[i].getCodeName()))&&(password.equals(users[i].getPassword()))){                     System.out.println("\n\nCorrect");                     new Game();                 }                 else{                     System.out.println("\n\nIncorrect");                 }                }              input = JOptionPane.showConfirmDialog(null, "Incorrect Username/Password\nWould you like to try again?");                    }         while(input==0); //run while input is yes     } }   FULL CODE for UserData:  public class UserData {      private String codename;     private String password;      UserData (String codeName, String password)     {         this.codename = codeName;         this.password= password;     }       String getCodeName()     {         return codename;     }       String getPassword()     {         return password;     }       public String toString ()     {         String temp = "\nCode name: "+codename+"\nPassword: " + password;         return temp;     }     }


Log in Windows 8 account automatically, keeping it locked

I want my PC to automatically log into my Windows 8 account and run all the startup programs, with out me giving my user name and password. (I have done this myself).   But I also want my PC to be locked until I log in myself. I don't want it to be in an insecure state.


Are double negatives like 'he's never not been in the family' grammatically correct?

I'm asking this question because I was taught not to use double negatives, because they are ungrammatical and that people who use them sound uneducated. However, today here on this site I found an answer with a double negative and asked my self is it correct to use double negatives? Well my doubts arose since this answer has eight positive votes. Even though I understand the meaning of it, I still wonder if it is correct or not. Below is the answer I'm talking about as well is the link to it.  Answer:     "It might add the subtle extra nuance of meaning that since you were born he's never not been in the family."   Link:   P.S. Not trying to put this site and the people from it in doubt, just clarifying and making sure to learn well this beautiful language.


Do Skill Feats and Rogue's Expertise stack?

So there's  that features skill feats. Taking one will provide proficiency for its relevant skill and if you are already proficient, you double your proficiency bonus. However, this functionality is already provided by the Rogue's Expertise class feature.    Which begs the question, how do these two features interact? If my Rogue has expertise in Stealth and takes the Stealthy feat, what is my total bonus for Stealth checks? x2 (doesn't stack), x3 (proficiency is added twice), x4 (bonus is doubled and doubled again), or something else?


Can I use the Ubuntu font in a proprietary application?

Huge Ubuntu fan here, I really like the Ubuntu font, but as far as I know you may only use it in open-source applications. I want to use it in an iPhone/iPad app. Due to Apple's contracts, I can't make the project open-source.  So, the question actually is, is it allowed to use/distribute the Ubuntu font in an iPhone/iPad application (free or paid)? Would be great if that's allowed!


i run into some problems with the shading in the tail of the airplane. but i did not know what cause the problem. can any help?


Oracle/PostgresQL nextval procedure - the simplest realisation

What wrong here? I'm looking the simplest way to realise sequence nextval over true primary key ID, stored into the table  DECLARE smth NUMBER; LOOP    smth := (select gen_ns_ces_id.nextval from dual);    EXIT WHEN smth > (select MAX(ID_NS_WORK) from CES.NS_CES) END LOOP;      CREATE SEQUENCE  "CES"."GEN_NS_CES_ID"  MINVALUE 1 MAXVALUE   9999999999999999999999999999 INCREMENT BY 2 START WITH 1837 NOCACHE    NOORDER  NOCYCLE ;   ID    NAME 1845  JONNY ..    ....


I am a first-year Math undergraduate and have been searching online for books in Analysis and have found two which seem to be good for an introduction.  Ross' Elementary Analysis:The Theory Of Calculus. Abbott's Understanding Analysis.  I did a quick skim at the content and it seems that Abbott's Understanding Analysis has more content（breadth) but Ross' seems to go deeper? I am not sure which book to choose (self-study) and any other recommendations/suggestions are welcome and highly appreciated!


How to get one's creative juices flowing again?

I wanted to post this in case anyone else is going through what I am experiencing. I haven't done a lot of artwork in the past few years. I was trying to get back into a grove. But, I found that I was trying to do these big projects that I would always stop shortly after starting. (I do 3D projects in SketchUp and also do a lot of pencil and pen drawing. I sometimes use Paint.Net. I have started to work with Inkscape. Many years ago I took some college classes on Photoshop, Illustrator and some other graphic programs. Having worked as a board artist and having done a lot of pen and ink drawing in the past before there were computers, I really thought the Pen tool was the coolest thing ever. I still enjoy using it. )  OK - So...I was trying to get back to doing some creative work. I found a Zentangle book in the library just by chance. I flipped through it and saw some nice ink work. I took it home and tried it out. It got me going again. I am pretty sure that it was because you work with a small space (3.5" x 3.5") and go through a sequence of steps to get going. And, that's what it did: It got me going. I was able to actually finish some Zentangle projects. I took photos of some designs and I'm planning on reworking them in Inkscape. I am also going to try to do some bigger works. The more I do the little squares, the more I see that ideas are coming to me more easily. I don't really copy the ideas in the books. But, I do flip through them and try to modify some of the basic ideas.


Rings in which every maximal ideal is finitely generated

Suppose that $R$ is a commutative ring with unity in which every maximal ideal is finitely generated. Then is $R$ Noetherian?


Let $\alpha$ be an ordinal , and define $X_{\alpha} = \alpha \times [0,1)$ to be a topological space with the lexicographic order.  Denote by $\omega$  the first countable ordinal and $\Omega$ the first ordinal that is not countable.  I need to prove the following :  if $\alpha$ is countable then $X_{\alpha}$ is isomorphic to $[0,1)$ as ordered set and to conclude that $X_{\alpha}$ is homeomorphic to $[0,1)$.  and, for each point in $X_{\Omega}$ except the min. element there is a neighborhood that homeomorphic to $R$.  Im a bit stuck on this question, for the first part i thought sending $(n,x)$ to $x$ but this does not work. i tried also sending $(n,x)$ to anywhere in the interval $(1/(n+1) , 1/n)$ - this also does not work.  I would really appreciate a detailed answer , as im not familiar that much with ordinals.  Thanks for helping.


How to describe this unrecognizable content?

In programming, I got the following content which is unrecognizable in the output. When communicating with others, how should I describe the issue I encountered in more natural way? In fact, this unrecognized contents should be other languages, like Japanese. For example, DeltaGundamk デルタガンダム。But the program didn't deal with this correctly.    Is garbled characters the term to describe these characters?  Chinese developers call it 乱码. Japanese developers call it .  Links: 1.


can a character take a dash action multiple times in one round?

if a character is given the ability to take the dash action as a bonus action or take multiple actions on the same turn, can said character use all of them to take the dash action?  considering a wood-elf, monk-fighter multiclass with a bunch of wizard friends about to take part in an Olympic event. the wizards sneak up and caste haste, longstrider, and expedited retreat on him at the same time. the person would have a base movement of 65 feet + 10 feet for longstrider and 3 dash actions per turn. (5 with action surge) with a movement speed of 225 ft per round (37.5 ft per second) or 375 ft/round (62.5 ft/s) with action surge. other than local traffic laws is this scenario valid RAW.  addendum; if it is possible to take multiple dash actions on the same turn, can a rogue attempt to hide multiple times on a single turn?


How to remove execute flag from ntfs drive

Recently, I installed Ubuntu 17.04 on a new ssd (standard installation with ext4), no other drive was connected at that time. After I connected my data hdd (ntfs formatted, it's a dual-boot setup with win7), I noticed that every single file on it got the execute flag (had a dual-boot with 14.04 before, but did not have this problem).  If I toggle the flag off on a single file, it is immediately reset. Also, every file that I copy to the hdd gets the flag and if I create a link to a hdd folder on my ssd, the link itself gets the flag after a renoot, making it unusable until I remove the flag (it is reset on the next reboot).  The entry for the ntfs drive in /proc/mounts :  dev/sdc1 /media/brad/mydata fuseblk rw,nosuid,nodev,relatime,user_id=0,group_id=0,default_permissions,allow_other,blksize=4096 0 0    Why did this happen (I did not do anything that should have caused this/how to prevent it from happening next time)? How do I safely undo it for the whole drive at once without touching/changing each file (also without changing file date stamps)?   Re:duplicate:  I don't see what this would have to do with chmod, I don't want to change file or folder permissions, I need to correct how ubuntu is seeing the whole drive because that has been changed and I think that change was a very bad decision. So now I have to edit fstab to get the pre-16.10 behavior back. There is no mention of this situation or of the 'correct' (old) permissions one has to set in "How do I use 'chmod' on an NTFS (or FAT32) partition?". While renaming this question to "Reverting ntfs permissions to pre-16.10" might make it more unique, somebody with the same problem does most likely not know about the reason and therefore would not find this thread, so I keep it like it is.  Still waiting for the wrong "Duplicate" note to be removed. This is how a duplicate looks:


Resize thousands of images all to different sizes in batch. Name and size are given in excel file. How to do it?

Pardon me if this is a duplicated question even though I could not find a solution yet. I have about 1000s images. I need to resize them, each to a specific size. There are no patterns to those sizes. They are different. I have the file names and the sizes in an excel file. Manually it will take a lot of time. I was wondering if this can be done in a batch process. Maybe Photoshop Scripting or something else.   I do not know how to script but have the general idea of how it works.  What I want to do is indicate the folder and the excel/csv/text file and the batch will run and resize each file to the given height keeping the proportion.  Example:  1000s of Image files.  Named: file1, file2, file3, file4. etc...  file1 will have 975 px height  file2 will have 486 px height  file3 will have 846 px height  All keeping the proportions.  Hope that clarifies what I'm trying to achieve.


How do i add a variable as the name of the variable i want to checks value. My code is as below, when i run this i get the error:  [: A_variable: integer expression expected   I think this is because when doing an if on a variable the proper syntax should be: if [ $A_variable -eq 1 ]; but i am not able to put the dolla sign in front of my variable because i am putting a different variable in the value of my variable.  Its almost like it should be: if [ $${letter}_variable or some mix of this but i dont know what?  array=("A" "B" "C")  A_variable=1 B_variable=2 for letter in "${array[@]}" do  if [ ${letter}_variable -eq 1 ]; then ...


How to write "smart" "phone" in British English?

In British English, how do you write smartphone? Is it:   Smart phone Smart-phone Smartphone


Which one is correct?     I ride a motorcycle.      I drive a motorcycle.


Is there a script that can list the fonts used in hundreds of ai files?

I have several hundred packaged .ai files but I need to know all of the fonts used is there a script or something that can generate a list of all the fonts?


In which levels are the Warp Zones located in Super Mario Bros. and how do you get to them?


How do I reformat datetime to ('DD/MM/YYYY')?

I have the following DateTime format that is outputted from an API.  2021-04-28T10:21:56.656Z  I want to be able to convert to the following format:  DD/MM/YYYY  I have tried using the datetime library but getting no where. Using python3 Thanks in advance


Tell KDE to store network secret in unencrypted file via commandline

I have run into a situation where I'd like to get my wireless working without the benefit of a monitor, by sshing in.  I have KDE on the system, have enabled autologin for one of the users and would now like to set up the wireless to automatically connect without kwallet prompting me for a password.  (That way I can ditch my ethernet cable and move my computer out of the way).  I assume that this requires me to store the password in an unencrypted file; that's just fine with me.  I've run across some ways to do that via the gui () but, for my circumstances, I need to be able to pull this off via ssh.  Would anyone know how to accomplish this?  It would be much appreciated.


Is overheating actually a risk for hardware, with all the internal safeguards now present?

Most computers now have safety things that turn them off if they get too hot (for example, according to the Intel website, my Intel T4400's T Junction is 105 degrees C).  With most internal safeguards most computers just shut off before they get too hot.   Thus, why is overheating considered to be so bad, when they turn off anyway before any real damage can be done?


List of countries an Indian can visit without applying for visa

Are there any countries an Indian citizen can visit without a visa?


In what order are chained implications evaluated? (i.e. $a \implies b \implies c$)

Implication does not appear to be associative:  a  b  c | (a -> b) -> c | a -> (b -> c) F  T  F | F             | T F  F  F | F             | T   Is $a \implies b \implies c$ evaluated as $a \implies (b \implies c)$ or $(a \implies b) \implies c$?


Sequential Least Squares for Tikhonov Regularization

Given a  problem where the cost function is given by:  $$ J = { \left( x - H \Theta \right) }^{T} {C}^{-1} { \left( x - H \Theta \right) } $$  There is a Sequential Solution for the cases we get a sample by sample of $ \left\{ x \left[ 0 \right], x \left[ 1 \right], \cdots x \left[ N \right] \right\} $  Namely, given $ x \left[ N + 1 \right] $ we can derive $ \hat{\Theta} \left[ N + 1 \right] $ by  $$ \hat{\Theta} \left[ N + 1 \right] = \hat{\Theta} \left[ N \right] + K \left[ N + 1 \right] \left( x \left[ N + 1 \right] - {h}^{T} \left[ n \right] \hat{\Theta} \left[ N \right] \right) $$  With the appropriate choice of $ K \left[ N + 1 \right] $ (Very similar to ).  The question is, can we have a sequential form to a  problem where the cost function is given by:  $$ J = { \left( x - H \Theta \right) }^{T} {C}^{-1} { \left( x - H \Theta \right) } + \lambda {\left \| W \Theta \right \|}^{2}_{2} $$  Is there such form?


Which site can I use to request example code for subjects that I'm new to?  I've tried Stack Overflow and Programmers in the past and my questions always get closed and voted down so I'm not sure if there is an appropriate site for this or not?  edit:  Some advantages of learning a new topic using examples:   Clearly defined starting point Start with what works, not what doesn't Working code provides motivation to explore more and learn more Provides only what you need, when you need it Differentiating between good articles and bad ones becomes easier (execute the code, see the result and either stick around or move on)


Is $f(x)=e^x$ the only solution to $f(f'(x))=f'(f(x))$?   In particular I'm interested in the qualitative properties of the such solutions.


I have a 100x45 dataset and I'd like to perform feature selection and classification/regression.   I'm currently using various techniques to check which one has the best performances, but I have a doubt about how to treat PCA + SVM or random Forest or CART. With other feature selection methods and elastic net, I'm performing Cross Validation (CV) to select the hyperparameters and to test the model, since I have few records and at the moment I'm not in the condition to increase them.   With PCA which is the best course of action? Train-test or CV? Should I perform PCA on the train set and then use the number of PCs on the test set? In the case of CV how can I proceed?


Why is gravity called the weakest force? How do we even compare forces? I am not talking about the natural values of the forces that we normally experience in our daily lives.... I mean to say, we don't know the magnitude of any force to it's extremity, right? It can always be larger... So on what basis do we compare forces in general? What is the basis for a fair comparison in this case?


Find the next element that is not immediate?

I want to find the first span element after class counter, in code something like this:

    It seems like the next() function only finds the immediate next element, so something like this:  $(".counter").next("span")   Won't work. The way I have been using is a bit lengthy and I was wondering if there was a shorter way, it is this:  $(".counter").nextAll("span").eq(0)   I think the closest() method in jQuery 3 will do the trick, but I am using 1.2.6 -- is there a better way to do this (am I just using next() wrong?)


I have a model that looks like   lm(y ~ lag(x, -1) + lag(z, -1))   So basically, this is a time series regression with exogenous variables, and I want to carry out a rolling analysis of sample forecasts, meaning that: I first used a subsample (e.g., 1990-1995) for estimation, then I performed a one step ahead forecast, then I added one observation and made another one step ahead forecast, and so on.  I have tried to work with rollapply, defining the model as arima(0,0,0) with xreg=lags of the other variables, but that doesn't work.   Your help would be much appreciated!


Java: can't properly implement custom Iterator

UPD:  is no help at all. My question is not about what is NullPointerException. I have asked with hope that someone will show me, what am I missing in in my Iterator class, so it gets a null refference. I suppose you should unmark my question so I can get an answer to my very question.   I decided to make my own implementation of one-way linked list without any java built-in classes or interfaces. At first, I created classes MyList and Nodes, and implemented some functionality for MyList, such as: adding new element to the end of the list, removing some element, checking, if the list contains some element, etc. It worked just well, you can see the whole project .  After that I thought I'm gonna need the iterator to go through the list. So, i have writted this class:   public class Iterator<T> { private Node currentValue; private MyList list;  public Iterator(MyList list) {     this.list = list;     this.currentValue = null; }  public T next() {     if (!list.isEmpty())     {         if (currentValue == null) currentValue = list.head;         else currentValue = currentValue.next;         return (T) currentValue.value;     }      return null;  }  public boolean hasNext() {     if (currentValue.next.equals(null)) return false;     return true; } }   I think the code of the Node would be useful here:  public class Node<T> {  public T value; public Node next;  public Node(T value) {     this.value = value; } }   Then, I've made a class for execution of the program:  public class ExecutiveClass { public static void main(String[] args) {     MyList<Integer> list = new MyList<Integer>();     list.add(5);     list.add(10);     list.add(15);     list.add(20);     list.add(60);      System.out.println(list.containts(10));     System.out.println(list.containts(50));      Iterator iterator = new Iterator(list);      while(iterator.hasNext())     {         System.out.println(iterator.next());     }  } }   And it seems like my Iterator doesn't work properly, because I've got this for output:  true Exception in thread "main" java.lang.NullPointerException false  at com.my.list.model.Iterator.hasNext(Iterator.java:40)  at com.my.list.engine.ExecutiveClass.main(ExecutiveClass.java:24)  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)  at   sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:483) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)   Process finished with exit code 1   So, how do I fix the Iterator, so it will work as expected?


C++ Inheritance - calling overrides from constructor

I'm trying to understand how method overrides work when the to-be-overridden method is called from a constructor.  (Using VS2012)  Given the test program:  #include <string> #include <iostream>  using namespace std;  struct Foo {     Foo()     {         cout << "\tFoo::Foo()" << endl;         Initialize();     }      virtual void Initialize()     {         cout << "\tFoo::Initialize()" << endl;     }  };  struct Bar : public Foo {     Bar()  {          cout << "\tBar::Bar()" << endl;      }       void Initialize() override     {         cout << "\tBar::Initialize()" << endl;     } };   int main(int argc, char *argv[]) {     cout << "Creating Foo" << endl;      Foo foo;      cout << endl;      cout << "Creating Bar" << endl;      Bar bar;      std::getchar();      return 0; }   I get the following output:  Creating Foo         Foo::Foo()         Foo::Initialize()  Creating Bar         Foo::Foo()         Foo::Initialize()         Bar::Bar()   I would expect the second section to be:  Creating Bar     Foo::Foo()     Foo::Initialize()     Bar::Initialize()   <---- Not called.     Bar::Bar()   I'd expect that, when the Foo ctor is called, and it calls ::Initialize(), that the override Bar::Initialize() is actually called.  Now, I can guess why this is happening: When Foo::Foo() is called, before the body of Bar::Bar() is executed, there's no guarantee that items needed by Bar::Initialize() have been allocated, much less initialized.  The Question  Can I override a method that is called by a base constructor, and have that override execute when instantiating a derived class? That is, is there any way to modify the above code so that Bar::Initialize() will be called?  The alternative I'm using at the moment is to remove the ::Initialize() from the Foo constructor, and do something like this:  Bar bar; bar.Initialize();   and modify Bar::Initialize() to  void Bar::Initialize() override { Foo::Initialize(); ///... bar-specific initialization here }   Is this the best or only way to do this?


ORIGINAL POST   This I would imagine is going to be a simple answer. I have Apache2 running on my Ubuntu server but it seems PHP is not installed. When I try to load a php page it does not load properly.   Example:  (My Site)   At first I thought the php module was simply not loaded but when I try to run sudo a2enmod php but it did not work and I get this error: ERROR: Module php does not exist!  Thanks for help in advance!   EDIT  After trying to load a simple PHP page to show the php version I have gotten a new error trying to load the page. that error is visible here:  . This makes me think I have more of an Apache issue than a php issue. I have a main Apahce sever that proxys all incoming traffic to each server inside my network. The Apache config for the main server looks like this:   <VirtualHost *:*>         ServerName MaxKulik.net         ServerAdmin max@maxkulik.net         ProxyPreserveHost On         ServerName "www.MaxKulik.net"         ServerAlias "MaxKulik.net"         ProxyPass / http://192.168.1.5/         ProxyPassReverse / http://192.168.1.5/         ErrorLog ${APACHE_LOG_DIR}/error.log         CustomLog ${APACHE_LOG_DIR}/access.log combined </VirtualHost>  <VirtualHost *:*>         ServerName MaxKulik.net         ServerAdmin max@maxkulik.net         ProxyPreserveHost On         ServerName "www.MaxKulik.net"         ServerAlias "MaxKulik.net"         SSLProxyEngine On         SSLProxyCheckPeerCN on         SSLProxyCheckPeerExpire on         ProxyPass / https://192.168.1.5/         ProxyPassReverse / https://192.168.1.5. </VirtualHost>  <VirtualHost *:*>         ServerName USI         ServerAdmin max@maxkulik.net         ProxyPreserveHost On         ServerName "www.UrbanTurtles.servegame.com"         ServerAlias "UrbanTurtles.servegame.com"         ProxyPass / http://192.168.1.28         ProxyPassReverse / http://192.168.1.28         ErrorLog ${APACHE_LOG_DIR}/error.log         CustomLog ${APACHE_LOG_DIR}/access.log combined </VirtualHost>


Number of partitions of an integer into four parts

I'm interested in the following question: find the number of partitions of an integer (for example, 1000) into 4 parts not exceeding given bound (for example, 511). How to approach this? If there was no restrictions for parts, the answer would be  $C_{1003}^3$, but I don't know how to take into account those restrictions. Any suggestions?  Edit: parts don't have to be distinct.


I just want to check how safe (if at all) my PHP-MYSQL queries are, I'm using user data which is coming through $_POST and then validating - the validation process of all data includes using mysqli_real_escape_string() on the string and trim(). The nature of some of my inputs however means that I don't restrict any characters on user input. Is what I'm doing safe and if not how could it be improved.  An example of an insert query (where $name and $description are $_POST data values which have been through a validation function.)      $sql = "INSERT INTO company(company_name, company_description) VALUES('".$name."', '".$description."')"; $result = mysqli_query($con, $sql);   An example of a select query (where $companyid is user input, real_escaped and stripped)      $sql = "SELECT * FROM events WHERE event_company=".$companyid.""; $result = mysqli_query($con, $sql);   Thanks in advance.


I don't like _____ eating.   What will be better to use, them or their. I want to say  their way of eating .But, i want to cut it short, according to context.  Can I use the sentence this way, using 'them or their.


How to automate SSH login with password? I'm configuring my test VM, so heavy security is not considered. SSH chosen for acceptable security with minimal configuration.  ex)  echo password | ssh id@server   This doesn't work.  I remember I did this with some tricks somebody guided me, but I can't remember now the trick I used...


Any field automorphism of $p$-adics is continuous?

How do I see that any field automorphism of $\mathbb{Q}_p$ is continuous?


How can I solve this indefinite integral for an arbitrary integer $n>0$?  $$ \int{x^n e^x dx}$$  I could partially integrate it for small $n$, but that's not really a solution.    Edit: (TB) This question is closely related to: , but it is more elementary, because $n$ is an integer here.


Let $E=\mathbb{Q}(\sqrt{2},\sqrt{3})$ and $$ L = E \left( \sqrt{ ( \sqrt{2}+2 ) ( \sqrt{3} + 3)} \right) \ . $$ I want to show that $L/\mathbb{Q}$ is a Galois extension with the Quaternion group as its Galois group.   I know $E/\mathbb{Q}$ is Galois and $L/E$ is also Galois, but it is not true in general that if $K_1/K_0$ is Galois and $K_2/K_1$ is Galois then $K_2/K_0$ is Galois (take $K_0 = \mathbb{Q}$, $K_1 = \mathbb{Q}(\sqrt{2})$ and $K_2 = \mathbb{Q}(\sqrt[4]{2})$ as a counter-example).


Is it possible to change the keys windows uses for mousekeys?

Windows has a feature called . Is there any way to make it use other keys?  For example rather than use the numberpad I'd rather use QWE/ASD/ZXC instead of the 789/456/123 that it comes with.  I'm interested particularly in modern versions of windows (7/8/10)  This is slightly different from  as that solution isn't easy to toggle; with the built in mouse keys you can toggle the keys on/off with NumLock but for that answer you have to logout/reboot for it to take effect.


How to draw a rectangle with variable vertical height after a line of text?

I need to draw a rectangle (or a framed box) in several pages after some blocks of text. The rectangle must span horizontally the whole \linewidth after the text and vertically until the end of the text area of that page. The height must also be dynamically adjusted for the free space depending on the amount of text before. I've tried doing it with the tikz package but, honestly, that's way beyond my tex knowledge.  MWE  \documentclass[]{article}  \usepackage{lipsum}  \begin{document}  \section{Section 1}  \lipsum[1]  % Draw rectangle here with linewidth and that spans vertically  % until the end of the area text of this page  \newpage  \lipsum[2]  % Draw rectangle here with linewidth and that spans vertically  % until the end of the area text of this page  \end{document}


How to show the number of domains the disk is split into is $1+ C_n^2 + C_n^4$?

Assuming there are n points on a circle, then there are $C_n^2$ chords. If any three chords don't intersect in circle. How to show the circle will be divided into $1+ C_n^2 + C_n^4$ domains?  Picture below is a example of 5 points on circle.


With Photoshop, how to batch replace white background with transparent in the image

I have got hundreds images of products with clear white backgrounds. I would like to change the white background color to become transparent.   Is there a means of batch processing this particular process with Photoshop or any other applications?


How do I get Google search request completion suggestions from console?

When one starts typing a search request on Google search page, Google shows a dropdown with some popular completion suggestions. There are often useful or funny things there.  How do I get that list without GUI?  Expecting something like:  $ curl https://www.google.com/.... "How do I" ... | ... how do I love thee how do I get a passport how do I craft this again how do I live without you


In combat, what can change the order or value of initiatives?

I'm wondering if there is something that can modify initiatives in combat, something like "Slow" or "Haste" spell (they do completely different things, though). I'm thinking something that can add +5 initiative to overtake certain character turn. It does not have to be a permanent modifier.  I'm aware that initiative was meant to be . I also do not want the initiative for each creature to be re-rolled. Only modified.


How to determine whether a number can be written as a sum of two squares?

I know the following theorems:   A number can be represented as a sum of two squares precisely when $N$ is of the form $n^2 \prod p_i$ where each $p_i$ is a prime congruent to 1 mod 4 If the equation $a^2 + 1 \equiv a (\text {mod} p)$ is solvable for some $a$, then $p$ can be represented as a sum of two squares.  A positive integer $n$ is the sum of two squares iff each prime factor $p$ of $n$ such that $ p \equiv 3 (\text{mod} 4)$ occurs to an even power in the prime factorization of $n$   My problem is often which one to use and exactly how to use it.  Here is an example of a question:  Determine whether the following integers can be written as the sum of two squares. a) 363 b) 700 c) 34300 d) 325  For example, I figures 363 can not be written as a sum of two squares as it is of the form $4k +3$ where $k = 90$  For 700, which is not in the above stated form, I found $ 700 =2^2 \cdot 5^2 \cdot 7$ and 7 is the only factor $ p \equiv 3 mod 4$ and it is definitely not to an even power. Does this mean I'm done showing it is not the sum of two squares?  c) $34300 = 7^3 \cdot 5^2 \cdot 2^2$; again the power of 7 is not even.  d) Then I have $325 = 13 \cdot 5^2$ which has no prime factors congruent to 3 modulo 4. BUT $325 = 5^2(13)$ where $13 \equiv 1 mod 4$ and 5 is the $n$ mentioned in the first theorem. Is this enough to conclude that 325 is a sum of two squares?


how using regular expression for numeric not alphabets

Hello i want to validate that user can enter only digits and the digit may be a integer or decimal but not alphabets just decimal no how can i write the regular expression for this. help me thank you


Can someone tell me how I can show the following:      Consider the symmetric group $S_5$ and show that $(12345)$ and $(12)$ generate the group.


'Open in browser' redirects me back to the app

I'm using the SE app on an Android phone (Galaxy S5 OS 6.0).  When I try the option to view a question in a browser, it simply opens the same question in the app. It doesn't even try opening the browser.  Is this a common issue, or am I the only one experiencing it?  Things I've tried:   clearing defaults for the SE app, clearing defaults for my browsers, clearing data for the SE app, restarting my phone   Here's the option I'm talking about:


Is there a specific term for nullifying an intentional insult by accepting it as a compliment?

For Example: 1.) Women turned Trump’s insulting “Grab’em by the pussy!” into “Pussy Hats” that they sported proudly in The Women’s March. 2.) Trump also attempted to humiliate Hillary Clinton by comments about her pantsuits, and both men and women rallied by founding “The Pantsuit Nation” and by proudly wearing pantsuits to express their support of HRC.


In other discussions, e.g.  it is claimed that a polynomial in a field $K$ with degree greater than $1$, having a root in $K$, must be reducible. So by this criterion $X^3-1$ would be reducible over $\mathbb{Q}$ since it has a root $1 \in \mathbb{Q}$.  However other sources, e.g.  say that a polynomial in $\mathbb{Q}[X]$ is reducible only if it can be factored into two non-constant polynomials also in $\mathbb{Q}[X]$. So by this criterion it looks as though $X^3-1$ is actually irreducible, because although one factor is $(X-1)$, the other factors are $(X-e^{2\pi i/3})$ and $(X-e^{4\pi i/3})$ which are clearly not in $\mathbb{Q}$.  Is either of these definitions of irreducibility either wrong or non-standard, or are they in fact equivalent? If the latter, what have I overlooked?


CS6 Illustrator on Mac OSX 10.15 Catalina - anyone managed to run it?

I was browsing Internet for some hints, but did not find anything yet. And the communication is a bit missleading, one say it won't work, becuase of 32-bit references, another claim it should work, because CS6 Illustrator itself is 64-bit.  Ended up after install with:     and after clicking the icon:     “Adobe Illustrator CS6” needs to be updated.     according to      Adobe Mercury Performance System, 64-bit memory support, new user   interface, gradient on a stroke, pattern creator tool, ImageTrace   (replaces Live Trace)   From the OSX system information:  Adobe Illustrator CS6:    Version:  682   Obtained from:    Identified Developer   Last Modified:    19/08/2019, 14:06   Signed by:    Developer ID Application: Adobe Systems, Inc., Developer ID Certification Authority, Apple Root CA   Location: /Applications/Adobe Illustrator CS6/Adobe Illustrator.app   Kind: 64-bit   Get Info String:  16.0.0, Copyright © 1987-2012 Adobe Systems Inc.  All rights reserved.   so it is 64bit


Novel where government trains kids for the army through a VR game

This was only about 5-6 years ago but there was a book I remember reading a lot of in High School. It was about a girl and her little brother who lived in this sewer city beneath another city, there was a lot of cement. Their school bought into this government program to feed the kids a weird paste and then they all were playing VR pod "games" with aerial battles. Turns out the government was trying to build an army, the siblings find out the people living above them are the uber rich, both groups think outside this cylinder is nothing but death and pollution, but after going over the wall in a plane they find lush forests where the uber-uber rich are living.


Wifi driver missing after Ubuntu 20.04.1 LTS clean install on HP laptop

$ lshw -class network   *-network                         description: Ethernet interface        product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller        vendor: Realtek Semiconductor Co., Ltd.        physical id: 0        bus info: pci@0000:02:00.0        logical name: eno1        version: 15        serial: 38:22:e2:e7:80:06        size: 100Mbit/s        capacity: 1Gbit/s        width: 64 bits        clock: 33MHz        capabilities: bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation        configuration: autonegotiation=on broadcast=yes driver=r8169 duplex=full firmware=rtl8168h-2_0.0.2 02/26/15 ip=192.168.1.16 latency=0 link=yes multicast=yes port=MII speed=100Mbit/s        resources: irq:51 ioport:f000(size=256) memory:fce04000-fce04fff memory:fce00000-fce03fff   *-network UNCLAIMED        description: Network controller        product: RTL8821CE 802.11ac PCIe Wireless Network Adapter        vendor: Realtek Semiconductor Co., Ltd.        physical id: 0        bus info: pci@0000:03:00.0        version: 00        width: 64 bits        clock: 33MHz        capabilities: cap_list        configuration: latency=0        resources: ioport:e000(size=256) memory:fcd00000-fcd0ffff  Cable network is sound, wireless is "No Wi-Fi Adapter Found". Suspicious bits are "*-network UNCLAIMED", and no driver under wireless configuration. Also there's no driver for ubuntu at realtek web page (). The laptop originally had Windows 10 on it, and wifi was working fine. The answer to  didn't help. Where can I get the driver for this, and how to configure the adapter to use it?


I need to prove by induction that $3^n\geq n^2$  What I have so far:   Basis: $n = 1 \rightarrow 3^1 \geq 1^2 \rightarrow 3 \geq 1$ Condition: $3^n\geq n^2$ Assumption: $3^{n+1}\geq (n+1)^2$ Basis: $3^n\geq n^2$   $3^{n+1}\geq (n+1)^2  = 3(3^n) \geq n^2+2n+1 $  That's where I got stuck. I have no idea how to continue from there.


Are there any proofs that only exist by induction?

I've come to learn more about induction recently for proving things, and one thing stands out to me.  It seems like you could just data-mine patterns and guess a relationship you think might be correct, prove it with induction, and then that's it. You don't necessarily learn anything about why the underlying relationship is correct.   For example if I saw the Towers of Hanoi problem (number of moves to complete given number of discs $n$), I could theoretically just look at the data, guess $2^n-1$ and prove it with induction, and be right, even though I didn't need to go through generating functions or fancy recurrence expansions or characteristic polynomials and what have you.   This leads me to wonder:  Are there any proofs that exist by induction alone, i.e. where some other proof or derivation does not exist? Something that is true but not necessarily known why, through some alternative means?


Do I need a transit visa in Morocco to travel from Egypt to Spain through Morocco?

I am traveling by Royal Air Maroc and i am only staying for 5 hours in Casablanca airport during the trip from Cairo to Barcelona,and 3 hours only during the returning from Barcelona to Cairo and I'm Egyptian.


How to set umask so that directories to be `r-x` and files to be `---`

I want to set the default permissions for newly created directories to have r-x for others and those of newly created files (non-directory files) to have ---.  If I set the umask to 2, directory permissions get r-x but files' get r--.  I couldn't find any way to achieve what I want with umask.  Ultimately, I want others to be able to traverse the directories but not to read the content of the files. I think that is a very reasonable demand but eventually there seems to be no such setting.


Highlight tags corresponding to our favorites

Each of us have our list of favorite tags.  When a question has tag(s) that match one or more of ours, the background gets highlighted, drawing our attention to the question.  It would also be nice to highlight (perhaps using a bold font) the tags(s) that matched our own, so one could quickly do a further filtering of the question to see if it is of interest at the present time, like the following:    e.g. arduino is in my list of favorites, but the other two in each question are not.


A "wireless engineering" community in the Stack exchange?

As a engineer working on the wireless domain, I would like to propose to start a "wireless engineering" community in the Stack exchange.  The community will discuss topic as below  Cellular (includes LTE, WCDMA...etc) Short range wireless (802.11abgn/ac, Bluetooth, Zigbee, NFC...etc) Microwave, RF, antenna design and EM theory Subsystem of wireless technology such as IMS, wireless security, OSS..etc. Hetnet, small cell, wlan-offloading


I have the below python code:  x = range(3) x.append(x) x[3][3][3][3][0] = 5   The value of x after this is [5, 1, 2, [...]]. But, I dont understand how the parameter is passed in the above context. Can anyone please help me understand?


Risky to remove all i386 packages on a 64-bits install?

I don't use any 32-bits app on my 64-bits Vivid so i want to remove all i386 packages but I wonder if this can be done safely. Thx for help !  Edit : Here's the return from the 'dpkg -l | grep i386' command >


How can you add a custom marker/point on the vertices of a line feature?   There are only options to add them to the start/end of the line and equally spaced along the line.   However, a marker on the exact postition of each vertices seems not to be possible.


Which ubuntu to install on 32 bit machine having 4 gb ram

I have a 32 bit machine and had planned to install ubuntu 14.04 on it. I am confused because on the ubuntu download page it says 32 bit (for machines less than 2 gb ram) , since I have 4 gb of ram on my machine should i go ahead with installating the 64 bit . Also what about the other applications should i need to install 32 bit or 64 bit version of the app ?


I installed Ubuntu 14.04 on my sons computer, then through Ubuntu Software Center purchased MyCraft.  I received an email confirmation of the purchase, but no Product Key or download information.  How do I get and install this?


Quotient of the ring of integers of a number field by a prime ideal

There is something I do not understand in my lecture notes, mainly because I do not understand quotients very well. We consider a number field $K = \mathbb{Q}(\sqrt{d})$ where $d$ is squarefree.  If $\mathcal{O}_K$ denotes the ring of integers of $K$, it has a basis $\langle 1, \omega \rangle$ where $\omega$ is either $\sqrt d$ or $\frac{1+\sqrt{d}}{2}$ depending on $d \bmod 4$. We let $f(x) \in \mathbb{Z}[x]$ be the minimal polynomial of $\omega$ (so $f$ is monic of degree 2).  What I do not understand is first of all that we can write  $ \mathcal{O}_K = \mathbb{Z}[x] / f(x) $. Also, if $p \in \mathbb{Z}$ is prime, the notes then say $$ \frac{\mathcal{O}_K}{(p)} = \frac{\mathbb{Z}[x]}{(p,f(x))} = \frac{\mathbb{F}_p[x]}{f(x) \bmod p} $$  I do understand how to go from the first expression to the second(trivial when you know the above) but not how to go from the second to the third.  Also, the lecturer then gives the expression $\frac{\mathcal{O}_K}{(p)}$ when $p$ is ramified, split or inert. I do not really see why, in the sense how does it help to know that when $p$ is inert then  $$ \frac{\mathcal{O}_K}{(p)} = \frac{\mathbf{F}_p}{f(x)} = \mathbf{F}_{p^2} $$ for example ?  Thank you very much for your help !


How to use math.random with a minimum and maximum?

For one of my summer labs for comp sci, I have to make a program that takes input for a maximum and minimum variable, then have the computer pick a number in that range using math.random and then give the user 3 tries to guess it.  pretty easy but I can't find anything online that really explains how to do that with a simple math.random.  how can I do this?


My HDD is reaching a very high temperature, aprox. 50°, while using Ubuntu. On Windows it only gets as high as 40° and it causes the touchpad to get hot.  What can I do to determine what is causing this behaviour and how can I cool off my drive?  My notebook is a Toshiba A300-2D4 with an ATI Mobility Radeon HD 3470 graphics card.


I defeated all mechanical bosses, what do I do next?

So, Im playing Terraria, I recently defeated all mechanical bosses: The Destroyer, The Twins and Skeletron Prime. Ive gone to the jungle and got myself a full set of Chlorophyte and Im confused. What do I do next? (Im on PC by the way)


Is there (in universe, wherever) anything random? Do we know any event (or whatever else) which has no reason? Of course there are some things that we cannot see, measure but it doesn't mean that they haven't a reason.


How to draw line through group plots in pgfplots?

This issue has been driving me crazy for the past 10-20h. I have a group plot (pgfplots) where I have 2 plots one under another. I'd like to draw a vertical line (e.g. a helpline at x=150e-6) that would go through all of them.  When drawing inside the axis or rather nextgroupplot environment I can use something like this: \draw[thin] (axis cs:150e-6,\pgfkeysvalueof{/pgfplots/ymin}) -- (axis cs:150e-6,\pgfkeysvalueof{/pgfplots/ymax}); but this allows me to draw only on one of the subplots. If I go outside the axis environment I am able to draw on the entire {tikzpicture}, but I can't use the axis reference.  \begin{figure*}[h] \centering \begin{tikzpicture}  \begin{groupplot}[       group style = {group size=1 by 2, x descriptions at=edge bottom, vertical sep=0.2cm},       ytick={0, 1.8},       ymin=0,       ymax=3,       xmin=0,       xmax=550e-6,       change x base=true,       x SI prefix=micro]  \nextgroupplot \addplot table [x index = {0}, y index = {1}, col sep=comma] {plots/plot1reduced.csv};  \nextgroupplot[x unit=s] \addplot table [x index = {0}, y index = {3}, col sep=comma] {plots/plot1reduced.csv};  \draw[thin] (axis cs:150e-6,\pgfkeysvalueof{/pgfplots/ymin}) -- (axis cs:150e-6,\pgfkeysvalueof{/pgfplots/ymax});  \end{groupplot} \end{tikzpicture} \caption{Case 1} \label{fig:case1plot} \end{figure*}


Let $X$ be a real Banach space and $T: X \rightarrow X^*$ a linear operator such that $[T(x)](x) \geq 0$ for all $ x \in X$. Prove that $T$ is bounded. So, I need to prove that there exists an $M \geq 0$ such that $\|T(x)\| \leq M \|x\|$, for all $x \in X$. I can't really see where to start with this. Any help would be appreciated. Thanks.


Prove the differentiability of funtion $f(x)$ using the condition of $\lim\limits_{x\to0}\frac{f(x)-f(ax)}{x}=A$.

$f(x)$ is a continuous function, for some fixed $a\in(0,1)$ and some real number A satisfy $$\lim\limits_{x\to0}\frac{f(x)-f(ax)}{x}=A$$ Prove that $f(x)$ is differentiable at $x=0$ and compute the value of $f'(0)$.


Low Quality Posts review queue no longer saying "recommend closure"?

It seems that there has been a regression in the "close" text in the Low Quality Posts review queue. For example, on , it can be seen that  is shown to have cast a "vote to close". As far as I am aware, a question cannot be closed by only sub-3k users from the Low Quality Posts queue, unlike how "Recommend Deletion" works. Is the display of "Close" instead of "Recommend Closure" not incorrect?


Why do these dark lines appear in render mode?

Black lines appear on my mesh when moved away from the origin. The black lines intensify as the mesh is moved further and further from the origin. The black lines only appear in the render view. Any help on the issue will be greatly appreciated. Attached is a photo of the issue and the blend file.