Has anyone noticed any tactical downvoting of their, or other people, answers?  For example, in a recent answer to a question, my answer described a possible solution.  Shortly afterwards, another answer appeared following the solution I had mentioned.    I know that this is completely in the spirit of the site, however my answer had been down voted even though it was still as valid as it ever was.  Another poster also had his equally valid solution down voted.  There is no way of knowing the reason behind the down voting, as no comments were left, but I am suspicious as to the ethics behind down voting someone else's valid answer in the hope of making their own answer more prominent.  Are people really that desperate to gain reputation?  I have seen comments in other posts that suggest that tactical downvoting has occurred.  So, does anyone think that it is acceptable to downvote another post, even though it is still correct but may not provide a complete answer, to make their own appear more favourably?


combinatoric question about organized people in a circle

I have 12 people that arranged in a circle and 6 balls. In how many ways can I divide them for couples to play ball that no one will be disturb by the other?  In other words:All the people arranged in circle i want to draw lines between every 2 people in the circle so that there are not cut between the diagonals.  Update: I thought more about it and the solution is exactly Catalan number of N/2, this is mean the solution of this question is Catalan number of 6= 132 options.  What is a legal arrangement is on the right, and on the left an illegal arrangement:    thank you


Find $(f^{-1})'(a) = f(x) = 2x^3 + 3x^2+7x+4, a=4 $  How do I go about solving a problem like this? What are the steps?


I am sure this is fairly simple, but I am just not getting it.   I am not sure how to show that $\liminf_n→_∞ A_n \ $ ⊆ $\limsup_n→_∞ A_n \ $  I guess I am not understanding lim inf and lim sup properly.


How to set the rotate center to be the center of the object iI want to rotate?

the cursor is at world origin, and I want to rotate, move, scale an object, but when I press the rotate/move/scale/ button, the rotate/move/scale center is at the world origin, the object I want to move is far away from world origin, how to set the rotate/move/scale center to be at the center of the object????  blender 2.81


Is it true or false that $\lvert P([0, 1]) \setminus P((0, 1)) \rvert > \lvert P(\mathbb{N}) \rvert$ ?  I need a hint because I don't see a way to solve this


Is the "Sir" title appropriate to use in business meetings?

I'm assisting a daily phone meeting with people from Asia, Europe and North America. One of the Americans is using "Sir" sometimes to address the team leader. Is it appropriate to address a colleague in the same job rank, by "Sir"?


Recent and pinned files and folders do not open when selected from taskbar icon right-click menu

Background  Pinning applications to the taskbar is working fine. When you right-click on a taskbar icon, you see recently-opened and pinned files and folders (e.g. I have Downloads pinned to the File Explorer taskbar icon)  The Problem  Clicking on one of these recent or pinned items should open it, but nothing happens when I click it. Clicking the taskbar icon does open the program.  What I've Tried:   Removing the pinned item, re-opening it, and re-pinning the recent file Recent items and pinned items 8 different taskbar icons, both pinned and recent items


Transfer of angular momentum during oblique impact with(out) adhesion

I am solving a problem of 2 identical spherical particles colliding.  The impact is oblique. I consider both normal and tangential contact forces. Tangential force is a combination of elastic force and friction.  I seems reasonable to me that after collision angular momentum should be the same for both particles, i.e. they start spinning in the same direction (particle B acting on particle A creates positive torque, particle A acting on particle B creates opposite force, but the sign of torque is the same).  This also agrees with some experimental and theoretical results.  The problem starts when adhesion force is added. What happens with the momentum transfer once particles stick together and therefore cannot spin relative to each other?  It seems to me that they must start spinning as a whole. However I cannot physically reason it quite well.   Any suggestions?   UPDATE: thanks for your replies. This is indeed a complex problem. To clarify some details: I am trying to follow a paper by Thornton & Yin, Powder Technology, 65 (1991), "Impact of elastic spheres with and without adhesion".  I am timestep integrating all of the forces involved, i.e. collision is not instantaneous (~100-300 timesteps). When the particles stick due to adhesion there is the effect called "peeling", and this occurs until critical value of tangential force is reached. Then sliding starts (either a rigid body sliding, i.e. pure friction or micro-slip, which is a combination of elastic force and friction, as by Mindlin and Deresiewicz (1953), ASME J. Appl. Mech,20, p327).   I have my simulation match the results of Thornton and Yin except the case of adhesion. The rebound angles (of particles' centres) match, so the model must be almost working, but the contact patch reflection angle does not (this one depends on spin of the particles caused by collision). This makes me think I am not implementing the transfer of angular momentum right in the case of sticking particles.  I will try to work out how to modify the angular momentum of the adhered pair from you replies and the paper you attached.


Suppose $f(x) = x^p + $ lower order terms. Then Asymptotically $f^{-1}(x) \sim x^{\frac{1}{p}} $ for large $|x|$. How can we bound the error in this asymptotic approximation in terms of $|x|$


how to get the last record when two columns have same values?

i want to get a last row based of Updated_ts on the bases of same gr_number and course  i am using below query.  select t.* from (select  st.gr_number,st.course,st.is_active_flg,st.status,st.updated_ts         ,sum(case when st.status = 'COMPLETED' then 1 else 0 end) over (partition by st.gr_number) as completedCourse,       sum(case when st.status <> 'COMPLETED' and st.status <> 'APPLICATION' and st.is_active_flg = 'N' then 1 else 0 end) over (partition by st.gr_number) as IncompletCourse       from admission_log st            join course cr on cr.course_id=st.course       order by st.gr_number,st.course,st.updated_ts      ) t where completedCourse > 0 and IncompletCourse > 0;   this query gives me result as     from above result i want only last value against the same gr_number and course based of Updated_ts  like     please help


How do the single photon energy and em-signal energy correlate?

If the photon (as a quantum of the electromagnetic field) has no defined(?) amplitude, how does (or where from?) the electromagnetic wave's amplitude appear?  The formulation of the question is not quite precise, but the main idea is if we cannot define the single photon's amplitude, since $E=hf$ only (are there any other equations?), how can we talk about an amplitude of an EM wave, which is carried via photons (EM quanta)?


Why are stars, planets and larger moons (approximately) spherical in shape (like, the Sun, the Moon, the Earth, and other planets)?


Why Does Software Updater Say No updates Available, but apt-get upgrade Shows updates available?

I normally use Software Updater to keep the system updated. However I occasionally will run apt-get upgrade from the terminal and I've notice there are times when Software Updater says there are no available updates but apt-get update shows some updates to packages.  I haven't been able to figure out why.


How do I change the default "www.example.com" domain for testing in rails?

I have a rails application which acts differently depending on what domain it's accessed at (for example www.myapp.com will invoke differently to user.myapp.com). In production use this all works fine but my test code always sees a hostname of "www.example.com".  Is there a clean way of having a test specify the hostname it's pretending to access?


Maximizing app window while persisting Menu bar on top

I would like to maximize all my app windows, especially browser windows. But I don't want to cover up the Menu bar at the top of the screen.  Right now, when I maximize Google Chrome for instance, it will expand all the way and hide the Menu bar, but when I hover the mouse pointer to the top, the window will jump up and down to reveal/conceal the Menu bar. I find this to be super annoying.  The first step of the dance routine:    The second step of the dance routine:    And, as I move my mouse up/down the view will toggle. I just want the Menu bar to always remain visible, but for my app windows to be maximized. Is that so hard?


My grenadier just ranked up to Captain and received a Hidden Ability, and I'm curious how many other Hidden Abilities are out there. Are any of them class-specific, and are their rarities (as in some abilities are rarer to get upon promotions than others) different or all the same?


Subfields of $\mathbb{C}$ which are connected with induced topology

The ring of continuous functions on $[0,1]$ to $\mathbb{R}$ has an interesting property:      every maximal ideal of this ring is the subset of all functions vanishing at a common point.    If we follow the argument in the proof of this property, it can be seen that $\mathbb{R}$ can be replaced by $\mathbb{C}$ and still similar property holds for new ring (we have to slightly modify argument).   What if we place $\mathbb{Q}$? Here $\mathbb{Q}$ is disconnected with induced topology from $\mathbb{C}$ and so the only continuous function from $[0,1]$ to $\mathbb{Q}$ are constant (am I correct?). So, the property no longer holds true with replacement of $\mathbb{R}$ by $\mathbb{Q}$.  Question: Are there subfields of $\mathbb{C}$ other than $\mathbb{R}$ which are connected as topological spaces with induced topology from $\mathbb{C}$?


what is a better way to check if two complex numbers are identical in python?

While testing mpi4py's comm.reduce() and comm.Reduce() methods in python 2.7.3 I encountered the following behaviour:   sometimes subtracting two complex numbers (type 'numpy.complex128', which are the output of some parallel calculation) that appear identical when printed on the screen produces a non-zero result comparing them with == occasionally yields False.   Example:  print z1, z2, z1-z2 (0.268870295763-0.268490433604j) (0.268870295763-0.268490433604j) 0j print z1 == z2 True   but then  print z1, z2, z1-z2 (0.226804302192-0.242683516175j) (0.226804302192-0.242683516175j) (-2.77555756156e-17+5.55111512313e-17j) print z1 == z2 False   I figured this had something to do with the finite precision of floats, so I resorted to just checking whether the difference abs(z1-z2) is bigger than 1e-16 (it never was - which is what one would expect if reduce() and Reduce() are equivalent). (EDIT: this is actually not a good way to check for equality. See here: )  I was wondering if there's a more straightforward way to compare complex numbers in python.  Also, why does this behaviour arise? After all, a float (and as far as I know a complex is basically a tuple of two floats) is stored on the machine in binary, as a sequence of bits. Isn't it true that if the two numbers are represented by the same sequence in binary, the difference should be zero and the comparison with == should yield True?  EDIT: OK, I found this , which basically boils down to the same thing.  But then the last part of the question remains: Why do floats work like that if in binary they are all basically represented by integers?


When do I use the possessive with "Tiffany & Co"?

Is there a grammatical reason for Tiffany & Co being made possessive in Breakfast at Tiffany's?


The value of $\sum_{1\leq l< m <n}^{} \frac{1}{5^l3^m2^n}$

How to solve this summation ? Also, I'm not sure what does $1\leq l< m <n$ supposed to imply in the development of summation form.  $$\sum_{1\leq l< m <n}^{} \frac{1}{5^l3^m2^n}$$  This one is from the Galois-Noether Contest in 2018:


I have an escrow check that is past 180 days.  It will be around 6 days past 180 come Monday. The check was issued by bank of america and my bank is chase.  Would they still let me deposit it or will another one have to be reissued?  How strict are banks with these things?  Would they tell me something like, too bad, your loss?  This is no small check.


Why my hot water goes out in less than 2 mins?

All the water outlets in my condo can only supply hot water for at most 2 mins and then I am left with cold water. I changed my gas water heater 2 days ago, but the problem continues. I was desperate when I thought the problem was finally resolved but was left with cold water again during a shower. Do anybody happen to know what is going on here ? Thank you a lot.


Is a visa required for an Indian citizen to leave an Italian airport during layover?

I am an Indian citizen in US on a F1 visa. I have a flight from Orlando to New Delhi in December 2021 with a 7 hour layover in Rome. My plan is to make use of this time and hit a couple of spots in the city. Can anyone give me an idea if I need to apply for a transit visa or a regular Schengen visa to get out of the airport and visit some places?


I have recovered some photos with Recuva and a lot of them have been recovered fine, however there are some that only half the picture shows and the other half is just grey, then there are others that won't show a picture for the thumbnail.  When I check properties it says the size, and each picture shows a different size so I assume there is content.  Please help! If I can load the pictures up somewhere for someone to check over please let me know how and where.


How to prove Gauss law geometrically (without coordinates) from Coulomb's law?

Namely that the Flux of the electric field through any surface equals the charge enclosed/vacuum permittivity.  Without any coordinates or reference to axis.


Today I was observing a clock and its movement, every second is an exact second on every clock.  I was making a comparison between a second and a meter. I know in France there is a metal stick one meter long and is a basic measure valid for every place on earth.  So I was wondering what is time measured against?  I don't know if my question is clear enough, but how do you measure one second?


Is the Stargate storyline continued after Stargate: Universe?

The Stargate storyline begins in the , and then continues in , then , and finally in .  Are there any films, novels, or TV series that take place in this universe after Stargate: Universe?  If there are none presently, are there any announcements of works in development?  (For example, the Stargate: SG1 series was extended through two films,  and , and both SG1 and Atlantis have several tie-in novels).


How to get pixel coordinates between 0,1 from SV_POSITION

I am new to HLSL and Directx. I was trying to write a simple gradient Shader by modifying one of Microsoft samples.  1.I can not understand why SV_POSITION is float4? If it is pixel coordinates shouldn't it have only x and y ? What are the 4 parts? I think SV_POSITION is not between 0,1 and the maximum val is bufferWidth,bufferHeight ... then how can I get the position between 0,1?   The first code does not work because distance between float2 and float4 is impossible. While the second one works I get a warning. How can I avoid the warning message because I believe something is wrong!   Fist code (Of course it should not work):  float4 VS( float4 Pos : POSITION ) : SV_POSITION {      return Pos; }  float4 PS(   float4 Pos : SV_POSITION) : SV_Target {     float distfromcenter=distance(float2(0.5f, 0.5f), Pos);     float4 rColor = lerp(float4(0,0,0,1),float4(1,1,1,1), saturate(distfromcenter));     return rColor; }   The second one :  float4 VS( float4 Pos : POSITION ) : SV_POSITION {      return Pos; }   float4 PS(   float2 Pos : TEXTCOORD  ) : SV_Target {     float distfromcenter=distance(float2(0.5f, 0.5f), Pos);     float4 rColor = lerp(float4(0,0,0,1),float4(1,1,1,1), saturate(distfromcenter));     return rColor; }   Why do I get this warning ? How can I compile this Shader using SV_POSITION to avoid the warning message ?  D3D11 ERROR: ID3D11DeviceContext::Draw: Vertex Shader - Pixel Shader linkage error: Signatures between stages are incompatible. The input stage requires Semantic/Index (TEXTCOORD,0) as input, but it is not provided by the output stage. [ EXECUTION ERROR #342: DEVICE_SHADER_LINKAGE_SEMANTICNAME_NOT_FOUND]


What happened to all of the clones after the clone wars?

So once Star Wars episode IV: A New Hope starts, the Clone Wars are over, but what is the fate of the clones? Are the stormtroopers in episodes IV, V and VI leftover clone troopers? Did the Kamino cloners keep making clones for the republic/empire after the clone wars ended? When did the empire start hiring actual real people (and not just using clones) for their armies?


I tried to run a basic C++ file on terminal:  #include <iostream> using namespace std; int main() {     cont << "This is my first C++ program!";     return 0 }   and then tried to run it in terminal:  Kawika-and-Chloe-Boss:~ kawikaandchloe$ make learningCPP.cpp make: *** No rule to make target `learningCPP.cpp'.  Stop.   and tried:  Kawika-and-Chloe-Boss:~ kawikaandchloe$ make learningCPP make: *** No rule to make target `learningCPP'.  Stop.   and tried:  Kawika-and-Chloe-Boss:~ kawikaandchloe$ gcc learningCPP.cpp -o learningCPP.out clang: error: no such file or directory: 'learningCPP.cpp' clang: error: no input files   Here is the entire bash/clang file:  Last login: Mon May 25 07:49:21 on console Kawika-and-Chloe-Boss:~ kawikaandchloe$ make learningCPP.cpp make: *** No rule to make target `learningCPP.cpp'.  Stop. Kawika-and-Chloe-Boss:~ kawikaandchloe$ make learningCPP make: *** No rule to make target `learningCPP'.  Stop. Kawika-and-Chloe-Boss:~ kawikaandchloe$ gcc learningCPP.cpp -o learningCPP.out clang: error: no such file or directory: 'learningCPP.cpp' clang: error: no input files Kawika-and-Chloe-Boss:~ kawikaandchloe$ $ g++ -o lab21 learningCPP.cpp -bash: $: command not found Kawika-and-Chloe-Boss:~ kawikaandchloe$ $ ./lab21 -bash: $: command not found Kawika-and-Chloe-Boss:~ kawikaandchloe$ ./learningCPP.cpp -bash: ./learningCPP.cpp: No such file or directory Kawika-and-Chloe-Boss:~ kawikaandchloe$ ./main -bash: ./main: No such file or directory Kawika-and-Chloe-Boss:~ kawikaandchloe$ $ g++ -o main learningCPP.cpp -bash: $: command not found Kawika-and-Chloe-Boss:~ kawikaandchloe$ cpp make learningCPP.cpp run     asdklajdl;jaksld  sadddasdfasddas df  dsa f dsa   Can you help?


Difference between Geographic-3D and Geocentric CRS

I'll start with the OGP definitions:   Geographic. A coordinate reference system based on a geodetic datum and using an ellipsoidal (including spherical) model of the Earth. This provides an accurate representation of the geometry of geographic features for a large portion of the Earth’s surface. Geographic coordinate reference systems can be two- or three-dimensional. A Geographic 2D CRS is used when positions of features are described on the surface of the ellipsoid through latitude and longitude coordinates; a Geographic 3D CRS is used when positions are described on, above or below the ellipsoid and includes height above the ellipsoid. [...] Geocentric. A coordinate reference system based on a geodetic datum that deals with the Earth’s curvature by taking the 3D spatial view, which obviates the need to model the curvature. The origin of a geocentric CRS is at the centre of mass of the Earth.   In practice, I would identify the difference between, say, a Geographic-3D and a Geocentric CRS in the fact that the latter has a central point in the 3D space from which angles and elevation are computed (no ellipsoid is needed, Earth is spherical?), whereas the former refers to the datum/ellipsoid, i.e. latitudes, longitudes and heights are computed with respect to the ellipsoid.  Am I saying something wrong or missing something? Thanks.


I am taking a course in stochastic process this time. As I read through a couple of books every one mentioned that stochastic process is also a random process. So, my confusion is why we  call stochastic process just for a random process? For me random process makes a lot more sense than the stochastic process. I asked this question to my professor too but he replied me "I don't know."


Some programs can have an infinite runtime and produce infinite output. When used in a pipe with a command that finish, how does the pipeline knows when to stop ?  For instance, take yes (infinite output) with head:   yes | head -n 5   It will only yield 5 y.  Is the first command that end the one that stop the other processes input/output ? How does it works ?


Screen resolution repositioning? (Broken laptop screen)

I have a laptop with the top left corner's screen being broken - I can't see anything there. However it's just a small corner, so I'd like to know if there's something I can do to make Ubuntu not use that part of the screen at all - I basically want it to ignore 2 unity taskbars on the left, and re-position all the content.


struct with template member function cannot be used as template param unless using template deduction

Below code block won't compile when invoking template member function (on template parameter) without taking advantage template argument deduction. Can someone point out what I'm missing here, TIA.  struct Foo {     template<typename T>     void set(const T& thing) { } };  template<typename T> class Bar  { public:     Bar() {         // struct Foo declared          f.set(5);       // compiles         f.set<int>(5);  // compiles          // struct Foo via template parameter type T         t.set(5);       // compiles         t.set<int>(5);  // doesn't compile     }      Foo f;     T t; };  int main(int argc, char* argv[]) {     Bar<Foo> b; }   Code also available at


Is it possible to scale specific apps on Windows 10?

We know that with the Windows 10 feature Display Scaling is possible to change the size of text, apps and icons. Once you set a value, this is applied to ALL texts, apps and icons. I just want to set this feature for specific apps. One example: 125% is set to default, but when I use an IDE like Eclipse or Visual Studio I want the scaling at 100%. Is it possible?


Failure to download extra data files [pepflashplugin-installer] download issue

I've searched through all the messages relating to this issue & have tried all the solutions but still get this persistent box that pops up. It happened after a recent software update about a couple of weeks ago. I've tried solutions found here:     Still have problems. When I re-installed, I got this info in my terminal:  Unpacking flashplugin-installer (11.2.202.644ubuntu0.16.04.1) ... Processing triggers for update-notifier-common (3.168.2) ... flashplugin-installer: processing... flashplugin-installer: downloading http://archive.canonical.com/pool/partner/a/adobe-flashplugin/adobe-flashplugin_20161108.1.orig.tar.gz Get:1 http://archive.canonical.com/pool/partner/a/adobe-flashplugin/adobe-flashplugin_20161108.1.orig.tar.gz [27.2 MB] Fetched 27.2 MB in 8s (3,385 kB/s)                                              W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/adobe-flashplugin_20161108.1.orig.tar.gz' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) Installing from local file /var/lib/update-notifier/package-data-downloads/partial/adobe-flashplugin_20161108.1.orig.tar.gz Flash Plugin installed. pepflashplugin-installer: processing... pepflashplugin-installer: downloading https://dl-ssl.google.com/linux/chrome/deb/pool/main/g/google-chrome-stable/google-chrome-stable_52.0.2743.82-1_amd64.deb Err:1 https://dl-ssl.google.com/linux/chrome/deb/pool/main/g/google-chrome-stable/google-chrome-stable_52.0.2743.82-1_amd64.deb   404  Not Found W: Can't drop privileges for downloading as file '/var/lib/update-notifier/package-data-downloads/partial/google-chrome-stable_52.0.2743.82-1_amd64.deb' couldn't be accessed by user '_apt'. - pkgAcquire::Run (13: Permission denied) E: Failed to fetch https://dl-ssl.google.com/linux/chrome/deb/pool/main/g/google-chrome-stable/google-chrome-stable_52.0.2743.82-1_amd64.deb  404  Not Found  E: Download Failed Setting up flashplugin-installer (11.2.202.644ubuntu0.16.04.1) ...   What is preventing this from running properly & triggering this annoying pop up box? I've redownloaded multiple times. My Internet connection is on a T1 line, too.  Thanks for any help!


Probability Interval for Gamma Distribution

There is something that I am doing wrong in the exercise below and I would appreciate some help figuring it out.  Let $X_1, X_2, \ldots, X_5$ be a random sample from a $\Gamma \left(3,3 \right)$ distribution . Define $W=\sum_{i=1}^5 X_i $.    Obtain the distribution of $W$ and of $2W/3$ Find $c_1$ and $c_2$ such that $P \left( c_1 < W <c_2 \right)=0.95 $     Since $W$ is the sum of iid gamma variables, $W \sim \Gamma \left(15,3 \right)$ and now a straightforward transformation argument shows that $Y=\frac{2}{3} W \sim \chi^2 \left(30 \right) $. This completes question 1.  Now for question 2, my thoughts were to transform these probabilities using the result from question 1, namely that $\frac{2}{3} W \sim \chi^2 \left(30 \right) $. Hence, unless I have made a horrible mistake here:  $$P \left( \frac{2}{3} c_1 < Y < \frac{2}{3} c_2 \right)=0.95 $$  We can find the constants from a chisquare table for $30$ degrees of freedom. In my case, they are $16.791$ for the lower bound and $46.979$ for the upper one.   Then if we equate $\frac{2}{3}c_1=16.791$ and solve for $c_1$ we should be able to find the constant for the above gamma confidence interval, right?   The problem is that according to $R$, $P \left( W<c_1 \right) =1 $, instead of  the desired $0.025$ which means I have gone wrong somewhere. I do not think it is in question though $1$ as I have verified the result many times.   Thank you.


Bibliography with chapters by different authors in a book

I'm currently writing a paper where I need to reference a a chapter within a book.  So, for example I have a book, which is written by several authors and have a title. Inside the book, there are different other authors in different chapters. So for example I have:   Book name: Book Title Authors of the book: Juan, D. and Dean, J. and Stark, T. Chapter title: Title of the chapter Author of the chapter: DiCaprio, L. Pages: 150-170   And then of course there are some publisher stuff and such.  My question is then: How should I be writing this in LaTeX ? I'm using BibLaTeX, and the book/article references given by:  @article{Xarticle, author    = "", title     = "", journal   = "", %volume   = "", %number   = "", %pages    = "", year      = "XXXX", %month    = "", %note     = "", }   and  @book{Xbook, author    = "", title     = "", publisher = "", %volume   = "", %number   = "", %series   = "", %address  = "", %edition  = "", year      = "XXXX", %month    = "", %note     = "", }   So yeah, I actually needs 2 titles, and 2 authors, at least in my head. But I can't figure out how to go about this ?  So any help would grateful.  Thanks in advance.  EDIT: So actually, in one of my articles, it says: "This chapter should be cited as"  Le Treut, H., R. Somerville, U. Cubasch, Y. Ding, C. Mauritzen, A. Mokssit, T. Peterson and M. Prather, 2007: Historical Overview of Climate Change. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.  So the main authors of the chapter, IN the book which different authors.  Can this be done in LaTeX ?


How can I see a history of the terminal output, not just commands entered?

I'm trying to do some debugging in Android and I am running a live logcat in the Terminal, but the problem is that there is too much information generated so that when I am finished and try to copy all the information received by choosing "Select All" and then "Copy" a lot of the early output which is produced isn't copied. I was aware of history, but that just provides a list of commands that have previously been entered, not the output.  Can I see a history of all the output that the terminal gives, or perhaps can I have the terminal save as a text file all the output that it is producing?


Can you target yourself with touch spells

I have been asked by one of my players “can I touch myself with a spell the has a range of touch?” Most touch spell say “you touch a willing creature of your choice,” or something along those lines. And my judgement is that you’re willing if you want to impose the effects on yourself. So I say, a touch spell is a spell that is kind of like a self that you can also use on other creatures or characters. Please correct me if I’m wrong and tell if I’m right.


I'm trying to prove that $(p-1)! \equiv - 1 \ \text{(mod $p$)}$ for some prime $p$.   From reviewing other answers, I've seen people cite a theorem stating that $(p-1)! \equiv p - 1 \ \text{(mod $p$)}$. However, I have not before seen this theorem, nor is it cited in my textbook prior to this theorem, so I don't believe I'm able to use it. I'm therefore hoping there is some other way to prove this without using this fact.   The best I've been able to do so far is to write that $(p-1) = 1 \cdot 2 \cdot 3 \cdot \ldots \left(p-1\right)$, and since $p \equiv 0 \ \text{(mod $p$)}$, $p - 1 \equiv - 1 \ \text{(mod $p$)}$. For this to work, then, the remaining terms must either be $1$ or $-1$ with an even number of $-1$'s for the negative sign to win out. I don't believe we can apply Fermat's theorem, as each of these terms lack an exponent, even though it's clear that, since $p$ is greater than each of these terms from $1$ to $p-2$, it can't divide any of that.   Any hints or insights on how to approach this problem would be greatly appreciated.


How can a user determine the path to an application being showed in launcher?  This is meant for non-programmers or experts, so terminal commands are not really suited for them. Why: we need to make our users able to drag files/folders on our applications, a standard OS feature entirely missing in Ubuntu.


I am using the concmath package (ultimately I only need the concrete font in the math environments but lets do it globally for now). My issue is: In the math environment I get a pixelated font. See this picture  This is the mini example I do for the result: \documentclass[english]{article}  \usepackage[latin9]{inputenc} \usepackage{concmath} \usepackage[T1]{fontenc}  \makeatletter  \makeatother  \usepackage{babel} \begin{document} Hey!$\lambda\beta\gamma\langle\psi\rangle$ \end{document}  Any idea how to fix this? Thanks a lot in advance!


I am creating a script which would enable me do something in a shorter amount of time. Is there a way that I can rename a file automatically from:  WDMyCloud_plexmediaserver_1.16.1.1291.bin(07082019)'   to  WDMyCloud_plexmediaserver_1.16.1.1291.bin   So it would detect the numbers, but would delete the part after .bin.  I am using Ubuntu.


How non-invasive blood glucose concentration measurement work?

Diabetes patients need to conduct the “fingerstick” a few times a day. One of the mechanisms of "fingerstick" is to take small amount of blood sample and put it onto a test strip. The enzyme on the test strip reduces the glucose and the electronics of the glucose meter detect the redox species produced. However, this method is painful and increase the risk of infection.  Photonic sensing technology opens up a new method for non-invasive blood glucose concentration. According to an article of  in 2013 (The link follows  ), the non-invasive kind was invented. By simply clipping onto the earlobe (without puncturing the skin), the blood glucose concentration could be measured. Does anybody knows the working principle for that? Or, suggest a paper describing that?


When I compile the following code  \documentclass[tikz]{standalone}  \usepackage{luatex85} \usetikzlibrary{positioning} \usetikzlibrary{calc} \usetikzlibrary{quotes} \usetikzlibrary{shadows}  \begin{document} \begin{tikzpicture}[   rect/.style={rectangle},   sum/.style={draw,circle,minimum width=0.2cm,minimum height=0.2cm,fill=white,drop shadow={shadow xshift=.3ex,shadow yshift=-.3ex}},   dot/.style={fill,circle,inner sep=1pt,outer sep=0pt},    pics/integrator/.style args={#1 and #2}{     code={       \node[sum] (-in) {};       \node[dot,right=1.5*\a of -in.center,"above:#2"] (-out) {};       \node[rect,below=0.5*\a of $(-in.center)!0.5!(-out.center)$,         "left:#1"{font=\scriptsize,yshift=-0.25cm}] (-int) {$z^{-1}$};       \draw (-in.center) -- (-out.center);       \draw[-latex] (-int.center) -| (-in.center);       \draw[-latex] (-out.center) |- (-int.center);     }   } ]     \def\a{1cm}   \pic (int) {integrator=$x_1(k)$ and $B_{coil}$};    \end{tikzpicture} \end{document}   with the lualatex compiler I get a strange error message:  ! Package pgf Error: No shape named intcurrent path bounding box is known. l.29 ...c (int) {integrator=$x_1(k)$ and $B_{coil}$};   When I remove the name prefix everything compiles fine.  Edit: I tried the workaround from the linked questions, by adding .center to every node, but that gives me the same error message as before. I also tested the passing of the name to the pic and resetting the name prefix inside the draw command. Also the same error persists.


How can a regression be significant yet all predictors be non-significant?

My multiple regression analysis model has a statistically significant F value however all beta values are statistically non-significant.   All the regression assumptions are met. No multicollinearity was found. Correlations among all predictors are all less than 0.60.   What else might be the cause of the insignificant predictors?


I watched this "Animated Flag" Tutorial from Blender Guru and he didn't explain how to actually export the animation at the end of the video.  How do you export an animation in Blender?


I have an stock, locked, Telstra Australian Galaxy S5 and I'm about to live in the UK.   I would like to know if there is currently a way to unlock it without code so I can use it with an English carrier.   I've searched a lot about this but results are highly polluted with commercial links.   Thank you


Past flight arrival time needed. How do I find it?

Need to know when EasyJet flight EJU8872 leaving Amsterdam May 1, 2019 at 13:30 arrived at Gatwick?


Prove that there is no set $\Omega$ such that $(\forall A)(A \subseteq \Omega)$  (1) I rewrite this proposistion as: $$(\forall x)(\forall A)(x\in A \Rightarrow x\in \Omega)$$ (2) Since this relation is supposed to hold for all possible sets $A$, let's define $A$ as: $$A = \{x : x\notin \Omega \}$$ (3) Let's assume that $x\in A$, therefore $x \notin \Omega$ and so there exists a set $A$ such that $(\forall x)(x\in A \Rightarrow \neg(x\in \Omega))$, therefore the theorem is true.  Is my proof valid, clear and understandable?


Photons have momentum. So when a light passes through another light what happens? Do they collide and conserve momentum?   If they collide they should deviate (move away from the straight line at a certain angle) from their path. But that doesn't happen in ordinary life, why?


Colored text flow for demonstrating proof of a theorem

I have written a big proof in a frame. I used \pause command to uncover the logic step by step.   What I want to do is that in the 1st slide will contain a alerted redtext. 2nd Slide contain the previous sentence with black color and the current sentence is alerted red color. 3rd Slide should contain previous two sentence in black color and the current uncovered sentence in red color. And so on...   What I did is like the following MWE. But I want a color flow to highlight the current sentence content  \documentclass{beamer} \usepackage[english]{babel} \begin{document} \begin{frame}  sentence1   \pause  sentence2   \pause  sentence3   \pause  \end{frame} \end{document}


i'm a beginner in Blender. I'm making a school assignment where i need to use the bevel. When i try to bevel a corner, instead of only rounding the corner, it goes further than only the corner i've selected. I'm using the normal shortcuts: ctrl + B and scrolling to get more segments. I've tried multiple times and i can't find a solution anywhere...  Has anyone had this problem?  Thanks :)


i have   const char* hour = "Wed Mar 23 18:10:57 2016";   I would like to cut "18:10:57" in another new const char*


I have the following lines in my .bash_aliases file alias enw='emacsclient -nw' alias gie='enw ~/.config/git/ignore' alias ls='ls --color=auto'  and I don't understand how and why they all work (they do!). The second alias uses the first, which means that expansion has to be performed repeatedly to get an actual command. In fact, I can observe this by writing gie in the terminal and pressing Ctrl+Alt+e to expand manually. After pressing it once I get enw ~/.config/git/ignore, and after pressing it again I get emacsclient -nw ~/.config/git/ignore. However, an expansion strategy that simply expands until there's nothing to expand wouldn't work for the third alias since it's recursive, and the third alias works nevertheless. If bash can expand nested aliases, how does it avoid non-termination? Does it simply stop after a fixed number of steps? Or does it stop after it encounters the same alias twice in an expansion chain?


DocumentListener isn't printing a message

I was trying to write a program which would give me a message when something (xx) in this case is typed, but it doesn't print a message. Can you please tell me why that happens ?  I've also checked the code if it's equal to xx when I type it, and it is.   import javax.swing.*; import java.awt.*; import javax.swing.text.*; import javax.swing.event.DocumentEvent; import javax.swing.event.DocumentListener; class acc { public static void main(String[] args) { ramka ramka = new ramka(); panel panel1 = new panel(); ramka.show(); ramka.add(panel1); } } class ramka extends JFrame {   public ramka()  {   setSize(800, 600);      setTitle("Super duper programer");   Container kontener = getContentPane();   textfield pole = new textfield();   kontener.add(pole);   setDefaultCloseOperation(EXIT_ON_CLOSE);     sluchacz listener = new sluchacz();   pole.getDocument().addDocumentListener(listener);  }  } class panel extends JPanel {  public void paintComponent(Graphics g)     {   super.paintComponent(g);  } } class textfield extends JTextField {  } class sluchacz implements DocumentListener  {   @Override   public void changedUpdate(DocumentEvent e)   {}    @Override     public void removeUpdate(DocumentEvent e){}   @Override       public void insertUpdate(DocumentEvent e)            {           try           {          String input = e.getDocument().getText(0, e.getDocument().getLength()).trim(); if(input == "xx") {     String message = JOptionPane.showInputDialog("You've just typed ''xx''"); }     }      catch(BadLocationException ex)      {         }           } }


Buster Blader the DDS did not affect Destiny Hero - Decider effect; why so?

How come  with  set to dragons didn't stop 's effect from being activated?


We know that $\lim_{n\rightarrow\infty}(1+\frac{1}{n})^n=e$ and so I thought the approach to evaluating the limit in the question would be to just use this fact and substitute it into the numerator. This approach would tell us the above limit evaluates to $1$. However, that does not seem to be the correct limiting value. In fact, it evaluates to $\frac {1}{\sqrt{e}}$. Why is this so?


I am having trouble getting TeXstudio to produce IEEE style citations.  I am using biblatex.  When I compile the document, the citations are referenced by their ID, not by a number in brackets like IEEE should have.  Below is a sample of text from my document.  The bold face text is supposed to be [1] and [2], but instead is showing up as the ID field from my bibliography file.  In ShareLatex, the document works properly.    Sample Text:  "The dual extruder tool head was purchased from Lulzbot as a "Flexy Dually", since one of the dual extruders was the "Flexistruder" Flexy1. The "Flexistruder" is designed to feed flexible filaments like "NinjaFLEX" (a thermoplastic polyurathane, TPU NinjaFlex1)."  Code:   \documentclass[letter,11pt]{book} \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc} \usepackage{lmodern} \usepackage{amsmath} \usepackage{marvosym} \usepackage{siunitx} \usepackage{hyperref} \usepackage{graphicx} \usepackage{easylist} \usepackage{csquotes} \usepackage[english]{babel} \usepackage[backend=biber,style=ieee]{biblatex} \addbibresource{bibliography.bib}   In text, I used the "\cite{Flexy1}" command.    Bibliography:  @misc{Flexy1,      title={LulzBot TAZ FlexyDually Tool Head v1}, url={https://www.lulzbot.com/support/lulzbot-taz-flexydually-tool-head-v1-0},      journal={LulzBot TAZ FlexyDually Tool Head v1}, publisher={Lulzbot.com},     note={Accessed 06-09-2016} } @misc{NinjaFlex1,     title={NinjaFlex® Flexible 3D Printing Filament}, url={http://ninjatek.com/products/ninjaflex-filaments/}, journal={NinjaTek},      publisher={NinjaTek Products},     note={Accessed 06-09-2016}     }   I would really like to get the citations to show up as IEEE style, and would appreciate any help.  Thanks!


Setting a custom RGB background color in beamer

I believe I've correctly followed the manual in defining a custom background color in the example below.     But as the example shows, the background color is black rather than an extremely pale beige.    Could anybody advise what I'm doing wrong please?  \documentclass{beamer} \definecolor{MyBackground}{RGB}{1.0000    0.9451    0.6549} \setbeamercolor{background canvas}{bg=MyBackground} \begin{document} \begin{frame} Hullo world \end{frame} \end{document}


titletoc: Hyperref section number and page number

Using titletoc, is it possible to not only hyperlink the section name, but also the section number and the page number?  Solution:


I have a phrase which I want to write, but I'm not sure of the correct grammar.  I want to say:     He sat (dramatic pause) and I (beat) nervous of what he was about to say...   Would I write this as:     He sat. And I, nervous of what he was about to say...   Or     He sat, and I, nervous of what he was about to say...   Or are both wrong and there's a better way?


What exactly is happening in this Java code snippet?

Here is the code:      timer.schedule(new TimerTask()      {        public void run()        {             synchronized(this)             {                  try                   {                       // System.out.println(" ITERATION = ");                       pachubeCLI.update(78164);                     }                   catch (PachubeException e)                  {                         // If an exception occurs it will print the error message from the                         // failed HTTP command                         System.err.println(e.errorMessage);                  }                   catch (IOException e)                   {                         System.err.println(e);                  }                }         }     }, 0, 5*1000);   I can tell that the code is basically being used to schedule an operation using an object of the Timer class. The parameters passed to the schedule method , according to eclipse , are (TimerTask task,long delay, long period). But looking at this code , an entire block of code is being passed as the first parameter instead of a reference to the TimerTask class. I've never seen such a method before.  What exactly is happening here?   Some background: The schedule method of the Timer object is being used to update a feed on Xively(previously COSM(previously pachube)) periodically.  Also I don't know which tag describes what is happening here.If you do please add it or drop in a comment.


Is there some workaround to pass primitive variables by reference?

I have searched the internet and found nothing.  This is the example of what i want:  test() {         var a = 1;         var b = a;         b = 2;         console.log(a);  //I want the output is 2 and not 1     }   I know that objects and arrays are passed by reference and would solve the problem but i cant use that aproach.  I hope to have explained my problem well .


Alternatives to RC circuit for simple variable delay up to 2 minutes

I'm looking for a simple and cheap way of creating a variable delay of up to about 2 minutes.          – Schematic created using   I want to know if there's an alternative to using an RC circuit that is simple and cheap. Other concerns are secondary, within reason.  The problem with this circuit is it just seems a bit 20th century.   Firstly, the capacitor needs to be large physically because of leakage current and the small current required to turn Q3 on. This means the cost possibly leaves room for improvement. The size, weight and lifespan can probably be improved. The delay consistency can certainly be improved.  (Since the capacitor's internal leakage and other leaks will vary significantly with temperature, humidity etc). Plus there's the surge when the cap gets charged.  Are there any tricks I could use? I'm wondering if there are any off-the-shelf ICs which are dirt cheap that perhaps combine a small RC circuit and some way of configuring the delay that is perhaps implemented by a binary counter.  I'm still playing around with ideas so I'm not sure what there will be in the way of power rails; if necessary I could make a 5v rail available, but it would be useful to know if there's a solution that could work on as little as 1 volt. So this question is less about solving my specific problem, but checking that I'm not oblivious to some general purpose alternatives.  [Re: duplicate: This is not a duplicate question. The answers given for the question identified as a possible duplicate offer no improvement as requested by my question. A 555 timer still uses an RC circuit without a solution for a large capacitor!]


Why does the Ubuntu installer touch my internal HDD when I don't use any of its partitions and when I tell the installer to install GRUB on the external HDD?   I have tried this approach over the years, and this always happens. The latest attempt is with Ubuntu 18.04.  I know this sounds like a million-time-asked dup, but I am stuck. The fact that people suggest the VirtualBox work around, or they suggest to disable the internal HDD (which I can't short of unplugging it) indicates to me that this is surprisingly hard to fix.   I have a Thinkpad laptop. BIOS settings allow legacy boot devices. The internal HDD is dual boot Windows and Mint, and it is an UEFI boot method.  I want to install ubuntu on an external SSD drive and have this drive one of the boot options from BIOS. External HDD is a MBR partition style, so traditional boot method is required. The BIOS is set to be ok with this.  If I install onto the external drive via VirtualBox, it works. This means that what I want to do is possible. My internal HDD is completely isolated when I do this.   However, if I do the installation a more traditional way, it always screws up my internal HDD booting. That is, I have use a usb stick to make a live installer and boot from it, the normal way to install Ubuntu, things go wrong.  During the installation process, I can choose where to install grub. I choose the external drive. I would expect this not to touch the internal drive. But after installation, I can no longer boot from the internal drive. grub seems to be missing. I can boot from the external drive.   (I fix it by connecting the external drive and booting into the HDD installation, and using boot repair.)  Why is my internal HDD being changed by the install process when I have followed all advice to leave it untouched?


Is it possible to find the origin of a virus?

Is there any method with which you can determine the origin for a given piece of malware in Windows?  One of my PCs was recently infected with the  password stealing trojan. Is there any way to tell from what source this virus was downloaded from?


What are the 'types' of parametric down conversion?

I'm looking at photon entanglement, and everywhere in the literature there's a reference to 'type-II' parametric down conversion as a source of entangled photon pairs. I know what parametric down conversion is, and I understand the resulting entangled state of type-II parametric down conversion.  I'm guessing there's some sort of 'type-I' out there, but I can't seem to find a good comparison between the two.  What is type-I parametric down conversion?  Does it have anything to do with pairs of entangled photons?  I feel like I'm missing something.


Update from macOS Big Sur public Beta to official release

My MacBookPro is currently running macOS Big Sur Version 11.0 Beta. Now that an official release for Big Sur has arrived, is it possible to move to the public release, just like a regular software update? In the "Software Update" settings, it still looks like I am suggested to install the new Beta version, rather than the official release. How should I fix this?


How can I add a graticule similar to the DeLorme Atlas to a map in QGIS?

I've got a map in NJ State Plane (Feet) projection and want to add a grid to it with lat and long intervals of 1 minute, and 0.1 minute tick marks. I'm trying to do this in the grid tab in the print composer but getting wonky results (probably some user error here!


Specific derivatives have specific names. First order is often called tangency/velocity, second order is curvature/acceleration. I've also come across words like Jerk, Yank, Jounce, Jolt, Surge and Lurch for 3rd and 4th order derivatives. Is there a widely agreed list of names for these? How many orders have specific names?  In this case, I'm dealing with NURBs curves, so the "tangency" and "curvature" related words are to be preferred over "velocity" and "acceleration" words.


Question about integer congruence modulo positive primes.

I am going through a book on abstract algebra over Christmas break, and I've come across this exercise that I'm having trouble cracking. This is in the introductory section on modular arithmetic and congruence classes, so it's more relevant to number theory than algebra. Here it is:  If $a$ and $b$ are integers such that $a\equiv b\,(\mbox{mod }p)$ for every positive prime $p$, prove that $a=b$.  Here's what I've tried:  Direct proof. I've tried beginning under the assumption that $a\equiv b\,(\mbox{mod }p)$ for every prime $p$. By definition, this means $a-b=pk$ for some $k\in\mathbb{Z}$. To show that $a=b$, I'd have to show that $k=0$. Right? I can't come up with a way to get to this conclusion. Contrapositive Proof. I've also tried beginning under the assumption that $a\neq b$. For this method, I'd need to show that there exists a positive prime $p$ such that $a\not\equiv b\,(\mbox{mod }p)$. I like beginning here since it only requires that I find one such positive prime, but it's complicated in the sense that I need to show noncongruence, which I know is more difficult than showing congruence.  I have a feeling that one of these two proof methods will work. I thought about doing a proof by contradiction, but that lost momentum pretty quickly. Any hints as to how I should proceed would be greatly appreciated. This is just for fun, so no rush. Thanks.


Derive Weierstrass product theorem from Mittag - Leffler theorem

This question is from Ponnusamy Silvermann's Complex analysis section Mittag-Leffler Theorem and I am struck on this.  Derive Weierstrass product theorem from  Mittag-Leffler theorem  I am confused on how I should prove it as Mittag-Leffler theorem guarantees the existence of a meromorphic function which has poles at a sequence ${b_n}$ while Weierstrass theorem is about proving existence of an entire function that has zeroes at a sequence of points. So, if I take a sequence $a_n$ that has no finite limits points. I am not sure how I can use Mittag-Leffler theorem to prove the existence of an entire function which has zeroes only at $a_n$, in fact I don't have any intution. Can you please help in proving it.


Debian (.deb) package not installing in Ubuntu 16.04

I want to install google-chrome-stable debian (.deb) package but it doesn't install. The process succeeds, but Google Chrome doesn't appear. I use this command:  sudo dpkg -i /home/aakaashsingh/Downloads/google-chrome-stable.deb


the app shows NullPointerException: Attempt to invoke virtual method on a null object reference, when nothing is null

I've just started learning android and i am trying to open an activity upon clicking on a textView. As far as I can see, there is not problem with my code, and I debugged it but couldn't find any calling to null. This is the exception:  Process: com.example.yuval.happybirthday, PID: 8057                                                                            java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference                                                                                at android.content.ContextWrapper.getPackageName(ContextWrapper.java:131)                                                                                at android.content.ComponentName.<init>(ComponentName.java:77)                                                                                at android.content.Intent.<init>(Intent.java:4214)                                                                                at com.example.yuval.happybirthday.NumbersClickListener.onClick(NumbersClickListener.java:19)                                                                                at android.view.View.performClick(View.java:4811)                                                                                at android.view.View$PerformClick.run(View.java:20136)                                                                                at android.os.Handler.handleCallback(Handler.java:815)                                                                                at android.os.Handler.dispatchMessage(Handler.java:104)                                                                                at android.os.Looper.loop(Looper.java:194)                                                                                at android.app.ActivityThread.main(ActivityThread.java:5549)                                                                                at java.lang.reflect.Method.invoke(Native Method)                                                                                at java.lang.reflect.Method.invoke(Method.java:372)                                                                                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:964)                                                                                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:759)   This is the Main activity:  package com.example.yuval.happybirthday;  import android.content.Intent; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.TextView; public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);     NumbersClickListener pls = new NumbersClickListener();     ((TextView) findViewById(R.id.numbers)).setOnClickListener(pls); } }   This is the NumberClickListener class:  public class NumbersClickListener extends Activity implements View.OnClickListener { @Override public void onClick(View view){     Intent i = new Intent(view.getContext(),NumbersActivity.class);     startActivity(i); } }   And this is the numbersActivity class:  public class NumbersActivity extends AppCompatActivity {  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_numbers); } }   I tried debuggin it severl times and just couldn't find where the problem is.


Compute $\int_0^{\frac {\pi}2} \ln(\cos^2x+y^2\sin^2x) dx$

Compute: $$I(y)=\int_0^{\frac {\pi}2} \ln(\cos^2x+y^2\sin^2x) dx$$  So$$I'(y)=\int_0^{\frac {\pi}2}\frac {2y\sin^2x}{\cos^2x+y^2\sin^2x}dx$$ Now what?


Evaluating the integral $\int_{0}^{\infty} \frac{\cos ax}{1+x^2}dx$

I encountered this problem while calculating the Fourier Cosine Integral for the function $f(x) = \frac{1}{1+x^2}$. I know that $\int \frac{1}{1+x^2} = \arctan x + c$. I just can't figure out what to do with $cosax$ term combined. If I do integration by parts, I get: $$\left [ \cos ax \times \tan^{-1}x \right ]_{0}^{\infty} +\int_{0}^{\infty}a \sin ax \times \tan^{-1}xdx$$ I don't know how to proceed after that. Perhaps a hint could help.


I am trying to add a sidebar to a Java application that will have a news feed from a website, most likely computerweekly.com, and will display the most recent stories with a link from the title to the online article.  I am pretty sure I need to somehow use an RSS feed, at least that's what seems to me would be the easiest way. But I'm exactly sure how I would do this.  Let's say I wanted the articles from this RSS feed:  to show up on the side panel of a project, could someone tell me how I would get started in doing so?   If I didn't explain that well enough, I'd be happy to try again, thanks all!


I've just heard the term covered index in some database discussion - what does it mean?


Given $|b-c|\leq a\leq b+c$ show that $\frac{a}{1+a}\leq\frac{b}{1+b}+\frac{c}{1+c}$

I am trying to show the following:  Given that $|b-c| \leq a \leq b+c$ show that: $$\frac{a}{1+a} \leq \frac{b}{1+b} + \frac{c}{1+c}$$  So far I have done the following: $a/(1+a) \leq b/(1+b) + c/(1+c) \iff$ $1-1/(1+a) \leq 2 - 1/(1+b) -1/(1+c) \iff$ $1/(1+b) -1/(1+c) \leq 1 + 1/(1+a) \iff$ $ (2+b+c)/(1+b)(1+c) \leq (2+a)/(1+a) \iff$ $ (2+b+c)(1+a) \leq (2+a)(1+b)(1+c) \iff$ $ a \leq bc(2+a)$ I am not really sure how to proceed from here- any help or hints would be much appreciated.


Proving $\frac{1}{n^2}$ infinite series converges without integral test

Just out of curiosity, I was wondering if anybody knows any methods (other than the integral test) of proving the infinite series where the nth term is given by $\frac{1}{n^2}$ converges.


Any other words that use “dis-” as an amplifying prefix?

I remember hearing once about the etymology of disgruntled, probably based around a joke about how people can not be gruntled. The explanation given was that there was never a word gruntled, rather the dis‑  in disgruntled is actually a usage of the old prefix where it acts like an amplifier.   Firstly, is this true?  Secondly, are there any other words that use this prefix in this way?


"package libmono-security4.0-cil is not ready for configuration" how to make it ready?

I'm getting this error  New software can't be installed, because there is a problem  with the software currently installed. Do you want to  repair this problem now?   And other than this error message popup has only two button. "cancel and "Repair"  And when I click repair, same pop up comes back.  My Ubuntu version is 14.04 LTS  jitendra@jitendra-Dell-System-XPS-L502X:~$ sudo apt-get install -f Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... Done The following packages were automatically installed and are no longer required:   cli-common libmono-corlib4.5-cil libmono-i18n-west4.0-cil   libmono-i18n4.0-cil libmono-security4.0-cil   libmono-system-configuration4.0-cil libmono-system-security4.0-cil   libmono-system-xml4.0-cil libmono-system4.0-cil libthunarx-2-0   libtumbler-1-0 mono-4.0-gac mono-gac mono-runtime mono-runtime-common   mono-runtime-sgen thunar-data tumbler tumbler-common xfdesktop4-data Use 'apt-get autoremove' to remove them. 0 upgraded, 0 newly installed, 0 to remove and 230 not upgraded. 1 not fully installed or removed. Need to get 0 B/110 kB of archives. After this operation, 0 B of additional disk space will be used. dpkg: error processing package libmono-security4.0-cil (--configure):  package libmono-security4.0-cil is not ready for configuration  cannot configure (current status `half-installed') E: Sub-process /usr/bin/dpkg returned an error code (1)     jitendra@jitendra-Dell-System-XPS-L502X:~$ sudo apt-get -f install Reading package lists... Done Building dependency tree        Reading state information... Done Correcting dependencies... Done The following packages were automatically installed and are no longer required:   cli-common libmono-corlib4.5-cil libmono-i18n-west4.0-cil   libmono-i18n4.0-cil libmono-security4.0-cil   libmono-system-configuration4.0-cil libmono-system-security4.0-cil   libmono-system-xml4.0-cil libmono-system4.0-cil libthunarx-2-0   libtumbler-1-0 mono-4.0-gac mono-gac mono-runtime mono-runtime-common   mono-runtime-sgen thunar-data tumbler tumbler-common xfdesktop4-data Use 'apt-get autoremove' to remove them. 0 upgraded, 0 newly installed, 0 to remove and 230 not upgraded. 1 not fully installed or removed. Need to get 110 kB of archives. After this operation, 0 B of additional disk space will be used. Get:1 http://ubuntu.uhost.hk/ trusty/main libmono-security4.0-cil all 3.2.8+dfsg-4ubuntu1 [110 kB] Fetched 110 kB in 1s (86.9 kB/s)                 dpkg: error processing package libmono-security4.0-cil (--configure):  package libmono-security4.0-cil is not ready for configuration  cannot configure (current status `half-installed') E: Sub-process /usr/bin/dpkg returned an error code (1)


Is it incorrect to say "I slept at six" in English?

I know there are many sentences like I went to sleep at six and I slept at six, but I want to know why it is incorrect to say "I slept at six" in English.


I am writing some technical documentation and I got confused when I saw the following paragraph title:     Steps to creating a new thing* in production   I think the correct title should be:     Steps to create a new thing* in production   But I'm not an English native speaker, the person who wrote it is, so I'm no sure.  * Replace thing with the real thing we do on production :)


Question about $\lim _{q \rightarrow \infty}\|f\|_{q}=\|f\|_{\infty}$

Let $(X,B,\mu)$ be a complete measure space,Show that $$\lim _{q \rightarrow \infty}\|f\|_{q}=\|f\|_{\infty}, \quad \forall f \in \bigcup_{p} \bigcap_{p \leqslant q<\infty} L^{q}$$ So,$\lim _{q \rightarrow \infty}\|f\|_{q}$ , $\|f\|_{\infty}$ are equal-norm with space $ L^{\infty} \cap\left(\bigcup_{p} \bigcap_{p \leqslant q} L^{q}\right)$. Case 1: $m(X)<\infty $.It's easy to prove that. Case 2: $m(X)=\infty $. I have no idea about it,And I started to doubt the correctness of this conclusion. Can somebody give me a hint for this problem or just give an example to prove that this is a wrong conclusion when $m(X)=\infty $. Thanks in advance.


How To Install And Test KDE Plasma 5 On Ubuntu 14.04

KDE Plasma 5 is hitting release candidate now: .  How can I install plasma 5 in Ubuntu 14.04.


How to comparing two x significant doubles correctly

This is not a duplicate question. There is an answer posted in the question. Hope it can help.  There are two doubles with the same value with decimals.  (Sorry, this is not a good case. because it will return false sometimes, but I can't find the case. If you try this case, it may not have any problem. So don't waste time to test it.)  double a = 0.70448; double b = 0.70441;   I want to compare them with only 4 decimals.  I have this helper function to round them down to 4 decimals first.  public static double RoundDown(this double value, int decimals) {     var multiplier = Math.Pow(10, decimals);     return Math.Floor(value * multiplier) / multiplier; }   And then I want to check if a is larger than b like this: RoundDown(a, 4) > RoundDown(b, 4)  Sometimes, for some cases, it will return true even they look equal. I understand very well this is floating issue, so I would like to know if there any elegant solution to compare them.  Updates:  I have tried to multiply it and compare them in integer. However, for this solution, I need to handle double infinity and NAN.      private static CompareResult Compare(double a, double b, double decimals = 0)     {         var multiplier = Math.Pow(10, decimals);         var aInt = Convert.ToInt32(a * multiplier);         var bInt = Convert.ToInt32(b * multiplier);         return aInt > bInt ? CompareResult.Greater : aInt < bInt ? CompareResult.Less : CompareResult.Equal;     }      private enum CompareResult     {         Greater,         Less,         Equal     }   System.OverflowException is thrown if one of the double is larger than int max or infinity. Also, this is not an elegant way to compare double.  Importants:   I am not going to round down with x significant figures. I have already provide this solution in my question, my question is: Even round down to x significant figures, it will return true when comparing them.  Again  I am not finding a way to round down or truncate the doubles to x significant digits. I have no problem on this part.  Answer  Thanks for @m88 answer. But it still cannot solve my problem. I finally solve this issue using sigma. (Reference: .)  Thanks to some people misunderstand the problem and vote it as a duplicated question. I can't post my answer for others facing the same problem. So I post the answer in my question. I hope it can help others.  public static int CompareTo(this double value1, double value2, int decimals) {     var diff = value1 - value2;     var sigma = Math.Pow(10, -decimals - 1);     return Math.Abs(diff) < sigma ? 0 : diff > 0 ? 1 : -1; }


How do I keep enemies from clumping up into one area?

I am making a zombie game and as I was making it I noticed the zombie AI starts to clump up into one mega zombie in one area. I was wondering how I could keep the zombies from doing that and instead make a horde like formation. I don't know how I would implement this and I don't know where to put it in my game logic so if you could give me some ideas or hints that would be fantastic.  Thanks in advance!


Upgrading camera or lens or both for landscape?

When taking a landscape photo with a deep depth of view, the image is not sharp, especially the further away it is. Up close sharpness is fine but not far away. I am using the correct aperture and have a sturdy tripod.  I am currently using a Canon EOS 4000D with its 18-50mm kit lens. I believe this camera has crop sensor, and I am looking for a upgrade that will give me better quality, whether its upgrading the body, lens, or both.   Is it true that full frame sensors have better quality than cropped sensors?   What would be the best thing to do in this situation? (As in upgrading and upgrading to what?)


Would using an underscore in a domain name have a negative effect on ranking?

What do you think the effect on search engine ranking will be if one uses an underscore in a domain name?


$l^2+m^2=n^2$ $\implies$ $lm$ is always a multiple of 3 when $l,m,n,$ are positive integers.

Let $l,m,n$ be any three positive integers such that $l^2+m^2=n^2$   Then prove that $lm$ is always a multiple of 3.


Let $(x_n)$ be a sequence defined by $x_1=1/2, x_{n+1}=x_n-x_n^2$. It is easy to see, that $\lim\limits_{n\to\infty} x_n=0$. Now, define $y_n=n^a x_n$ for $a\in\mathbb{R}$. The question is, for which $a$ does $y_n$ converge to a nonzero limit? Obviously for $a\le0$ it converges to $0$. I think it should be $a=1$ and the limit is $1$.  It looks like the way to go is to investigate monotonicity and boundedness for various $a$. I wrote $$ y_{n+1}=\left(\frac{n+1}{n}\right)^a y_n \left(1-\frac{y_n}{n^a}\right) $$ Here I got stuck. I would appreciate any help.  Also, are the other "standard" ways to deal with such limits?


I installed Windows 8 on my MacBook Pro using Boot Camp. Now I've figured out I should have made the Windows 8 partition bigger. Is this safe to attempt using Disk Utility? If not, how do I go about accomplishing this?


The limit superior of R given as lim sup of $\frac{1}{\left| \left(\frac{1}{n!}\right)^\frac{1}{n} \right|}$ as n approaches infinity

What is the limit superior of  $\dfrac{1}{\left| \left(\frac{1}{n!}\right)^\frac{1}{n} \right|}$ as n approaches infinity?  So far I have been able to establish that $n≤n!$ for $n≥1$ which the gives that $\frac1{n!}≤\frac1n$ from there I used the sandwich theorem on $0≤\frac1{n!}≤\frac1n$ to reach the conclusion that $\frac1{n!}$ tends towards zero as $n$ approaches infinity. I am now stuck on how to deal with the exponent $\frac1n$.


I am very frustrated.  Turned the PC on, worked some time with my bluetooth mouse on, suddenly the mouse stopped working, the occasional OFF-ON the mouse did not help (as it usually does), I went to Settings, and acctually did see the Bluetooth settings dissapeared before me!  I read up everything, watched tutorials on Youtube, in Device Manager have found Bluetooth in hidden, but nothing worked to put it back on (in many tutorials the start looked the same, but did not fix it for me).  I tried to uninstal it, reinstal it from the Intel site.  The bluetooth is installed, services are running, still, its nowere to be found.......  This is the second time this happened - the first time it has fixed miraculously itsself after a few hours of me reading up and trying everything...........when I gave up, in some time it just resumed.  Please help, I have spent all night on it...... (tried everything written and in all youtube tutorials), it did not happen after update, I tried updating the driver first, followed all the tutorials. The restore did not work, and now the restore point is gone........  Do not want to refresh the PC....


What do you guys think about it?     "Ace Grit is a 16 years old Vestal boy" or "Ace Grit is a 16 year old   Vestal boy"?      "Ace Grit is 16 years old" or "Ace Grit is 16 year old"?   Actually I still guess weird that it is "year old" instead os "years old", I didn't know anything about it, I just want to know please about what is the fact about "year-old-like" somebody, one person or two person, but in an age, younger and/or older.


Why is goto considered evil in Java and other high-level programming languages?

Possible Duplicate:          Why is goto considered evil in Java, and why is is not suitable for use in high-level programming languages?


Why didn't the fake Mad-Eye Moody ever tell Voldemort about the Foe-Glass?

Barty Crouch Jr., while impersonating Alastor "Mad-Eye" Moody, had Moody's  in his office during Harry Potter's fourth year at Hogwarts. Near the end of the book, Harry Potter and the Goblet of Fire, the Foe-Glass shows Albus Dumbledore, Minerva McGonagall, and Severus Snape just before they burst into the room to arrest Barty Crouch Jr.  Barty Jr. had an entire year to learn about the Foe-Glass. He could have told Voldemort on any day that year about the Foe-Glass. If he did tell his master, I am sure Voldemort would have insisted on keeping the device for himself.  Voldemort could use the device to find out if any Death Eaters near him are really enemies.  Although the  says the Foe-Glass is a dark detector, we know from  and from the book itself that it shows the foes of whomever physically possesses it.  There is no indication he ever told Voldemort about it. Why not?


What is the closest general-relativistic equivalent of a "time slice"?

In a newtonian universe, one can talk of a "time slice", that is, the state of the universe at a given point in (global) time. In a "typical" classical universe, a time slice would contain enough information to fully compute the state of the universe at any other point in time, backwards or forwards.  So, disregarding what we know of quantum effects and talking purely of a general-relativistic universe, which concept is closest to a time slice?


In Star Wars: The Force Awakens, Rey can be seen wearing the same outfit wherever she goes. She wears it on a desert planet:   On an ice planet:   On a jungle planet:    Why is this? Shouldn't different environments require different clothes?  Why does Rey wear the same outfit in different environments?


I can't seem to import a model that I downloaded from the internet

I know about User Preferences. I know about enabling the different file formats. What I don't know is why I am not seeing any model in the viewport despite using File-Import-Wavefront(.obj)...


JAVA Swing GUI Components howto RTL view?

How can i make my Java Swing GUI Components [Right To Left] for Arabic language from NetBeans Desktop Application?


Does excessive sugar intake cause diabetes?

Assuming no weight gain, does a large amount of refined sugar intake increase the risk of diabetes?  To put it another way: In theory, if you took two identical subjects, and they each consumed the same amount of calories, but Subject A received 5% of their calories from refined sugar, while Subject B received 25% of their calories from refined sugar, would Subject B have an increased risk of diabetes?


How can you make the $<$, and $\leq$ signs bold?

How can you make the <, and the $\leq$ signs bold?  Thanks,


Save As PDF on Microsoft Word 2007 isn't embedding the fonts

When i use internal Word "Save As" PDF it never embed the font. When i use PDF Creator it works ok, but then i lose the bookmarks and cross references.  I'm using Windows 7, when i go to the font folder, the font i'm using "Font Embeddability" property is listed as "Editable", which i believe should be enough to embed.  If i set "Bitmap text when fonts may not be embedded" it displays the pdf correctly, but i cant copy the text.


I was solving a question and got struck in a sub-question which is,      If   $$x=\cos1°\cos2°\cos3°\cdots\cos89°$$   Find the value of $x$.   I don't actually have any idea on how to proceed on this question. Any hints are welcome. The answer given in the book is a perfect integer $17$


Conjecture for a closed form of a parametric integral

Let us assume that $n \in \mathbb{N}$. It is quite easy to prove that:  $$\int_{0}^{1} x^{n-1} \log (1-x) \, {\rm d}x = - \frac{\mathcal{H}_n}{n}$$  since if we use the series representation of $\mathcal{H}_m$ we have that:  \begin{equation} \mathcal{H}_m = \sum_{k=1}^{\infty} \left [ \frac{1}{k} - \frac{1}{m+k} \right ] \tag{1}\end{equation}  and it follows that our initial integral , call that $\mathcal{J}$ ,   \begin{align*} \mathcal{J} &=\int_{0}^{1} x^m \log(1-x) \, {\rm d}x \\   &= - \int_{0}^{1}x^m \sum_{n=1}^{\infty} \frac{x^n}{n} \, {\rm d}x \\   &= - \sum_{n=1}^{\infty} \frac{1}{n} \int_{0}^{1}x^{m+n} \, {\rm d}x\\   &= - \sum_{n=1}^{\infty} \frac{1}{n \left ( n+m+1 \right )}\\   &= - \sum_{n=1}^{\infty}\left[\frac{1}{(m+1)n} - \frac{1}{(m+1) \left ( m+n+1 \right )} \right]\\   &= - \frac{1}{m+1} \sum_{n=1}^{\infty} \left [ \frac{1}{n} - \frac{1}{n+m+1} \right ]\\  &\overset{(1)}{=} - \frac{\mathcal{H}_{m+1}}{m+1} \end{align*}  Now let us raise the exponent of $\log (1-x)$ by one. That is we now consider the integral  $$\int_{0}^{1} x^{n-1} \log^2 (1-x) \, {\rm d}x = \frac{1}{n} \left [ \mathcal{H}_n^2 + \mathcal{H}_n^{(2)} \right ]$$  The derivation is pretty much easy. What can we say for the integral   $$\mathcal{J}(n, m) =\int_{0}^{1} x^{n-1} \log^m (1-x) \, {\rm d}x $$  I have a conjecture that states that it will involve a sum of $\mathcal{H}_n$ raised to the corresponding power of the log and a sum of $\mathcal{H}_n^{(m)}$. However, I am unable to make any progress for the general case. Diffing the Beta won't help us here. This is what I've done for the $m=2$ case. I just diffed the Beta twice. Any clever approach?  Also what we can say for the integral:  $$\mathcal{J}^*(n, m) =\int_{0}^{1} x^{n-1} \log^m (1+x) \, {\rm d}x $$  Well, one last thing one should note is that both integrals actually connect to . Maybe we could use the Taylor series expansion of $\log^m (1 \pm x)$ and reduce the problem to Stirling numbers. I am not that familiar though.


Why doesn't right-click work on my desktop?

I installed elementary OS and e17 on my Ubuntu 12.04 from ppas. After logout and login, right click on desktop is not working in gnome and unity but working in file manger.When I login into Pantheon session, I don't find an option to open Home folder and my login display manager theme is also changed.I want to get back to default Ubuntu login theme.Can i change the login theme with simple-lightdm manager. I dont want to mess up my system.Please hemp me how to fix these.


I would like a brief explanation of the following command line:  grep -i 'abc' content 2>/dev/null


Spacing between caption and section title

this is my first question, I hope I am right here. My problem is, that I have a float that is placed on a new page above a new section, as I want it by using the placeins package. However the spacing between the caption of the figure and the new section is less than the spacing between normal text and a new section, like in this example: \documentclass{scrreprt} \usepackage[utf8]{inputenc} \usepackage{blindtext} \usepackage[draft]{graphicx} \usepackage[section]{placeins} \usepackage[onehalfspacing]{setspace} \usepackage{parskip} \setlength{\parindent}{0cm}  \begin{document}  \section{This is a test} \blindtext\par \blindtext \section{This section has normal spacing above it} \blindtext \begin{figure}[htb]     \centering     \includegraphics[width = \textwidth]{test.png}     \caption{This is a caption with a somewhat longer text, therefore I write stuff untill at least one line is full.}     \label{fig:my_label} \end{figure} \section{This section has less spacing above it}  \end{document}   How do I change the space between the caption and the section to be the same as between normal text and a section? I already tried adding `\vslace, but it didn't work, probably because the float gets set behind the vspace and even if it worked, I wouldn't know, how much space was right. Thank you and best wishes, Jannik


Have installed chrome on Ubuntu. However cannot find where to run it

The installer says chrome has been installed.  It does not show up in Software Center.


If a person has plastic soles, and are playing on Artificial grass and then the person touches metal goal post, the person will get a static shock.. Why?


Can I use my own classes and packages in ShareLaTex or Overleaf

I would like to use my own classes and packages in all my projects and I wonder if it's possible to do that, working with Overleaf or ShareLatex.  Of course, I don't want to paste my personal .cls and .sty in each project.  Thanks for helping me


Can I multiclass and cast a spell I already know as a different class?

If I start with a Celestial Warlock with Cure Wounds and then multiclass into Bard, can I cast Cure Wounds as a Bard now, or do I have to learn the spell a second time to be able to cast it as a Bard?


If the only value in a share (excl. dividends) comes from owning part of a company (and few own enough) then why are stocks valuable?

Sorry if the title is a little vague, let me be more precise.   post says that the value in shares comes from:    The dividend payout Voting rights Owning part of a company, therefore receiving money in case the company becomes liquidated   Furthermore  post says that shares showcase the "health of a company".  But I have a few (naive) problems with this.  Firstly, some companies do not provide dividends, so while I can understand it as adding to a shares value this cannot be the underlying reason for shares having value.  Secondly, most people do not end up owning enough shares to have voting rights in a company. Are these people then holding onto shares in the expectation that if some big bucks fella comes along willing to buy these shares so that they can engage in voting rights that they'll be able to make money this way by selling to him? Furthermore, are voting rights really a motivating factor when people engage in the stock market?  Thirdly, I would imagine a company would only liquidate itself if it is not doing terrible well... at this point the share price would have dropped sufficiently to make the idea of recouping money through liquidation silly.. unless I am missing something?  My question would be what provides shares with value if not for the above three points, or have I confused myself?


is there a tool in blender that works similiar to how the looping tool in 3ds max works in which it will calculate my loop to auto clean my geometry. or make a curve i've been using loop tool addon however it it doesn't clean existing geometry just curves. It would be helpful if the tool also does like in max moves the edges to the center between the two existing edges. the tool that i'm looking for is set flow. if there are other tools like this in blender or a good addon to add similiar functions that would be helpful i dont want to spend hrs cleaning geometry if it can be sped up.      so if the geometry is screwy like this i need to clikc the loop flow a few times to get this thats what i am looking for


How can I make sudo discard all environment variables?

People usually want to preserve their environment variables while executing sudo for various reasons, but, there are some cases where discarding environment variables makes much more sense. For example, on Ubuntu, $HOME (along with a few other variables) is carried over to the process spawned as root; however, this makes no sense when trying to use Linux containers.  One could obviously edit /etc/sudoers to configure this behaviour, but I'd like to keep this behaviour and resort to discarding environment variables only for certain commands. There is a -H flag, but that is only for $HOME and doesn't really help in my case since I need to unset all variables.  How should I go about doing this?


Rotation systems. Problem interpreting an equation

In this equation:  $$ \mathbf a_i\overset{\rm def}{=}\left(\frac{d^2\mathbf r}{dt^2}\right)_i=\left(\frac{d\mathbf v}{dt}\right)_i=\left[\left(\frac{d}{dt}\right)_r+\boldsymbol\Omega\times\right]\left[\left(\frac{d\mathbf r}{dt}\right)_r+\boldsymbol\Omega\times\mathbf r\right] $$ (), why is  $$\left(\frac{d}{dt}\right)_r \boldsymbol{\Omega} \times \mathbf{r}=\frac{d\boldsymbol{\Omega}}{dt}\times\bf{r}+\bf{\Omega}\times \bf{V_r}$$  In particular, I have qualms with the term  $$\frac{d\bf{\Omega}}{dt}\times\bf{r}$$  Why are we deriving the angular velocity? Why is it a derivative not of the rotational type (Namely $(\frac{d}{dt})_r$ )  Other sources do not point out that term I have problems with. In any case, I want to know how you evaluate that derivative.


Hard time using EventListener on dynamically created element with pure JavaScript

Hi all I am a software engineer working on cloud computing(Mostly scripting). I wanted to learn web development and started with some basic course and learnt HTML,CSS. But when i came to JavaScript in the beginning it was fine, but later when it came to dynamic elements i started getting difficulty in eventListner to those dynamically created element with plan JavaScript. whereas with jquery its way easy with function like on(). The thing is, while learning all these i came up with lots of articles and youtube videos about javascript have evolved a lot and jQuery not so much relevant in 2020. so my question is   1) As a beginner in web development Should i avoid jquery totally.   2) or jquery is still very much thriving and should i mix both and learn.


Windows 10 and Ubuntu do not dual boot (after multiple attempts to fix)

The title is quite self explanatory. I have been struggling with this problem for a few days now. To start off, I have a laptop with Win10 and a SSD+HDD system. The SSD is 250GB so I have space to play around with it. Currently Win10 is installed in the SSD and the HDD is mainly used as extra memory.   Firstly, I did a fresh windows 10 install. This was due to the fact that my BIOS was set to Legacy, and when I wanted to install Ubuntu I got "the force UEFI installation message". So I decided to disable Legacy mode and reinstall Win 10 in UEFI. After that, I have followed multiple guides to install Ubuntu.   At first, I tried the first option in installation to install automatically along Win10. After the install finished, the laptop booted automatically into Win10. No boot manager, no grub, no nothing.   I assumed that the install messed up something so    I tried again using the something else method. I mostly used . Still didn't work. When I turn on the laptop it just boots automatically into Win10.   When I went in the BIOS to check the boot order I have first: USB, HDD, OS Boot manager, Network. These are my only options, no Ubuntu. I have also tried to move some of these up and down and see the results, no change.


Python all combinations of one item per list

I have a varying number of lists of varying length. I need to try to create all possibilities of having one item per list. How can this be done in Python? Example l1 =  ['a', 'b', 'c'] l2 =  [1, 2] l3 =  [6]  # Expected result: [   ['a', 1, 6],   ['a', 2, 6],   ['b', 1, 6],   ['b', 2, 6],   ['c', 1, 6],   ['c', 2, 6], ]  I could have 3 loops in this case, but since this is for an ambiguous number of lists it doesn't scale. I tried playing with itertools a bit but couldn't figure out what to use for my case and couldn't find similar questions here. So any help would be appreciated.


Ubuntu 16.04 software center doesn't have many apps

I have just installed Ubuntu 16.04 32-bit.   When I opened its software store, I found that it's not showing the apps I installed in Ubuntu 15.10 like Clementine, Gdebi package installer or synaptic package manager, dconf, acetoneiso etc.   I need these applications. How can I install them?


I know a lot of people really want to get lots of SO rep points to improve their quality of life. I get it. When I read a question, I think about whether I know the answer or not. If yes, then I take the time to write up what I deem to be a reasonable answer. If not, then I think about whether or not I want to try to figure it out. If so, and if I do, then I repeat the "know the answer" step. I don't try to flash answer questions. I'm just not the type.  But what's bugging me lately is the copy cat answerer. I read a question. Think. Formulate an answer. Then answer. This takes at least a few minutes. Four times this week, about 5-10 minutes after I post my answer (which comes 10 or more minutes after the question is posted), someone else posts the exact same answer! Even the same code with the same variable names! That's annoying. I don't really know why it bugs me so much, but there you have it. I'm annoyed.   In my annoyance, I feel like voting the answer down. But technically it's a correct answer, so I shouldn't do that. Maybe I should leave a comment? Maybe I should let it go? Probably the latter. Then again, duplicate questions are closed, why not close duplicate answers? Any suggestions?


Fantasy trilogy about a young man who travels into a fantasy world (doorway in a closet?) to save parents, who are royalty there

I may be able to get my answer to this the next time I'm home, but it's nagging me currently. It was a trilogy in paperback, released by 1998  because I remember seeing them up on my brother's shelf after I took over his room, which was prior to my graduation from high school. The front cover shows a young man in greyish camouflage fatigues, I think with two swords across his back. I only got partway into the first book before I set it down for reasons I don't remember, but the main character is a young man whose parents disappear. He finds a note, I think from his father, explaining that they are actually royalty from a fantasy realm and where the portal to said land is (I think) in the back of a closet in the house. Said young man starts to understand why it is that his parents had him doing so many anachronistic activities such as swordwork and archery. He arms himself (I remember him picking up swords, a bow and arrows, and woodland outfits, which he notes are in the closet in both camouflage and "Robin Hood green". He may have also picked up some guns). After he goes to the other world, he at one point freezes and notes that the key to avoiding motion when hiding in the woods isn't to hold your breath, but to rather breathe slowly and calmly. That part made an impression on me as a teenager for some reason.  I don't remember much of what happened after he traveled into the other world. I have this vague memory of him meeting someone at a ruined building, but that's pretty much it.


How can I have a "Dear %firstname%" template in my Gmail?

It seems to be a very easy thing but I am struggling to see how. I need a "Dear %firstname%,  [cursor here] Kind Regards etc" template in my Gmail account, so every time I click reply, it is already there. How can I do that?


This part C\frac{1}{\sqrt{G}}\sqrt{\rho} doesn't seem to be on the same height as this part \sqrt{b}\sqrt{l} when compiled. What am I doing wrong?  \begin{flalign*} T=C\frac{1}{\sqrt{G}}\sqrt{\rho}\sqrt{b}\sqrt{l} && \end{flalign*}


every rank 2 oriented matroid is realizable

Does anyone know where I can find the proof for why every rank $2$ oriented matroid is realizable?   Thank you!


Can adding both Asc and Desc indexes improve performance?

Was wondering if adding an ascending and descending index (on the same column) could allow SQL to search any faster by utilizing both indexes at the same time?


How does one prove if a multivariate function is constant?

Suppose we are given a function $f(x_{1}, x_{2})$. Does showing that $\frac{\partial f}{\partial x_{i}} = 0$ for $i = 1, 2$ imply that $f$ is a constant? Does this hold if we have $n$ variables instead?


I have the following class declared:  public partial class MainWindow : Window   And I need to get the actual handle of the window once the window has one. How can I do that and where should I put the query function.  What I tried so far was:  IntPtr hwnd = new WindowInteropHelper(this).Handle;   But the handle I get back is 0, which might be because it was planted in OnInitialized - maybe the window is not ready yet at that stage. And, yes - it is connected via WPF, thank you for pointing it out!  Thanks


Upvote requirements using Stack Overflow?

How does one simply (and quickly) provide feedback that an answer was helpful or vote UP on Stack Overflow without first establishing a reputation? I don't care about point games, but would still like to thank someone for their excellent answer, and subsequently saving me a bunch of time.  I'm fairly certain I'm asking this Stack Overflow-related question in the wrong place. I tried the tags meta.stackoverflow.com, getting started, and reputation, but they don't exist and can't be established without points.    Do I have to ask questions before I have the authorization to give any feedback?


Location keyframes shift (move) by script

I'd like write a script. There is an object with several keyframes. (example in 1,50,100,120 frames) I need an index and a shifting factor (let it index=2 and shift=30 frame)  The script need to stretch (or move) the keyframe after the index with shift factor. So when the script finished then the keyframe positions will be (in this case) 1,80,130,150)  I dig the blender API and I wrote some scripts already but I don't know what can I do. Please help me.


Do my analyze is correct? If don't then correct it.  Sentence: The tsunami and the undersea earthquake which triggered it, the largest ever recorded in the region, killed nearly 20,000 people, destroyed over 100,000 homes and threw the lives of tens of millions into turmoil.  Subject: The tsunami and the undersea earthquake Principal verb: triggered Adjective clause of subject:the largest ever recorded in the region, killed nearly 20,000 people, destroyed over 100,000 homes Use of parallelism:threw the lives of tens of millions into turmoil.


Suppose $f(z)=\sum_{n=0}^\infty a_n(z-a)^n$ converges for $|z-a|<s$ .   Then how to show that for $0<r<s$ , $\dfrac 1{2\pi}\int_0^{2\pi} |f(a+re^{it})|^2 dt=\sum_{n=0}^\infty |a_n|^2r^{2n}$ ?


How to encode a continuous function by a real number

In his book, Reverse Mathematics, John Stillwell says (pg. 44) "that each continuous function on R may be encoded by a set of natural numbers and hence the arithmetization project extends at least as far as the continuous functions. This remarkable result is due to Borel (1898), p. 109, and it follows that each continuous function may be encoded by a real number."  The referenced book by Borel is in French.  I can follow that a continuous function on R may be encoded by a set of natural numbers. But how does one go from that set to a real number specifically?  Of course I tried to search for this result on the innertube but, alas, I got nowhere. I'm not even sure what category in mathematics to start with to narrow the search down.  Also, given the real number, is it possible to reverse the encoding to get the continuous function back? Does every real number represent a continuous function? What book(s) are available to learn more about this intriguing result?


How do you clean a seasoned cast iron skillet?

I have a seasoned cast iron skillet, and I don't want to mess up the seasoning when I'm cleaning it.  What do I use and what don't I use to get it back to clean?  I've heard not to use soap and to make sure it is dry, but nothing beyond that.


How to validate memory correctness with VisualStudio?

Memory correctness means   use after free leaks use of uninitialized memory memory corruption   Other platforms have tools such as Valgrind or the address sanitizer.  Please note that I don't want to run my Windows binaries on Linux with Wine so that I might be able to use Valgrind. I would prefer a solution that fits a VisualStudio focused shop.  How do I do this on Windows in a VisualStudio environment?


I'm going to root my Samsung Galaxy Note and I come across the terms CWM and Odin very often. What exactly are they? It seems that CWM is used for rooting and Odin for flashing the phone. Is there more to it?  I've posted here because I have been unable to to find a good explanation online.


New camera won't focus while zoomed in, old one focuses perfectly. Why?

I take photos of computer hardware for sale on ebay. I had been borrowing a camera for photos (Olympus SZ-16) and the camera will be able to focus while very zoomed in to a device while relatively close. But since it was borrowed, I ultimately needed to buy my own camera. I'm not savvy on technical specs or anything like that. I just wanted a point and shoot camera that was modern and had good zoom. I didn't know about "Minimum focus distance" when I went to make my purchase.  So I bought a Canon SX740 HS. Took me a while to figure out the camera... turns out it has REALLY BAD minimum focus distance. The camera refuses to focus when zoomed in. How can I fix this? If I can't fix it, what stat should I look for for focus distance when zoomed in?  Here is a picture I took with the SX740 on a tripod. The object is about 40 inches away from the camera body. This is the closest I can zoom in before the camera refuses to focus. I can't even manually focus it to be in focus if it is zoomed in any further.   And here is a picture I took with the SZ-16. I can zoom in to the maximum 24x and it'll focus perfectly. Same deal, on a tripod, object is 40 inches away from camera body   So why does the SZ-16 have much better minimum focus distance than the SX740? What stat should I look for with respect to focus distance while zoomed in? What camera would you recommend for close-up telephoto images? Sorry if I used the wrong terminology. I think I'm going to return the SX740, because getting these super narrow field pictures is critical, especially if the item has a tiny defect that I need to display.


Cantor's diagonal argument shows that there is no bijection between the real segment [0; 1] and natural numbers. Does that mean that we can't enumerate this set ? If we take an application f(n) from N to R that, for any number, reverse it and place it after the comma, like it: f(0) = 0.0 f(1) = 0.1 ... f(1234) = 0.4321 ...  We clearly see that the application enumerate any given finite real in [0; 1]. What's wrong ?


How do you make a torus 'telescope' open?

So I have a torus, and I need it to "telescope" open -- kind of like Pacman's death animation, but with a torus instead of a sphere.  I'm very new to 3D modeling/animating so I really have no clue how to tackle this problem.  Any advice to help me get pointed in the right direction would be most appreciated :)


How do I get the date 30 days from when a user selects from calendar in JS

In my JavaScript, I have a calendar. The selection will look something like "04-01-2020". I have a function that checks if the from date and to date are over 30 days. How do I get the date 30 days from that date? I'm guessing I'd have to convert the "mm-dd-yyyy" to javascript's date format before converting back somehow.