everyone. I'm having a very difficult time understanding conditional statements, and was hoping someone could help me understand them. I took discrete math this last spring and remember struggling with them, but at some point had to let go and just say "it is what it is, I guess." I'm now taking a new course and conditionals are being thrown back in my face. I've watched several YouTube videos, read back over my discrete math textbook, did a google search and read the websites that came up in the first page and a half. Anything I do, I can't seem to grasp the meaning as a whole. Simply saying "if p, then q" or "p implies q," or "p is sufficient for q," or "q if p" does not make things clear. I understand a conditional statement is a compound statement made of individual propositions that are either true or they aren't true. I can also see how compound statements such as "It's raining outside AND it's cloudy" could, as a whole statement, be true. I've seen different definitions for what "if p, then q" mean, and they sometimes seem to contradict one another. So I'm going to ask it here. What is a conditional statement, and what does it mean? Further, in a conditional statement:  Why does a true hypothesis and a true conclusion make the conditional true? Why does a True hypothesis and a false conclusion make the conditional false? Why does a false hypothesis and a true conclusion make the conditional true? Why does a false hypothesis and a false conclusion make the conditional true?  Right now, I don't exactly know what questions I need to specifically ask to make it clear - all I know is I'm not getting it, and I'm exhausted with the run-around, lack of clarity, and simply not understanding. Hoping someone can help me. Thank you and hope you're all well. 5.

I am studying entailment in classical first-order logic.  The Truth Table we have been presented with for the statement $(p \Rightarrow q)\;$ (a.k.a. '$p$ implies $q$') is: $$\begin{array}{|c|c|c|} \hline p&q&p\Rightarrow q\\ \hline T&T&T\\ T&F&F\\ F&T&T\\ F&F&T\\\hline \end{array}$$  I 'get' lines 1, 2, and 3, but I do not understand line 4.      Why is the statement $(p \Rightarrow q)$ True if both p and q are False?  We have also been told that $(p \Rightarrow q)$ is logically equivalent to $(~p || q)$ (that is $\lnot p \lor q$).  Stemming from my lack of understanding of line 4 of the Truth Table, I do not understand why this equivalence is accurate.       Administrative note. You may experience being directed here even though your question was actually about line 3 of the truth table instead. In that case, see the companion question  And even if your original worry was about line 4, it might be useful to skim the other question anyway; many of the answers to either question attempt to explain both lines.


I want to know the function name that tells the location of where the session is stored.

Are $_SESSION variables stored on the client or the server?


So recently I downloaded the most recent ubuntu iso for installation alongside my Windows 8.1. Everything went really smoothly with no errors or hiccups during installation. The only thing is I've decided that I just wanna go back to using Windows 8.1. I haven't a clue how to uninstall ubuntu now. I was going to use the windows installer but there wasn't one available, however fund this latest iso which provided a much improved installer which as I said made things go a lot better.  Has anyone any idea how to uninstall it as I tried the DVD I burnt the iso to and all it gives me the option of is reinstalling ubuntu, there is no option to uninstall once I've installed.  Any ideas anyone?

I have absolutely no experience with Linux, and I desperately need to get my computer back up and running again with Windows.  How do I remove Ubuntu and reinstall Windows?    Editor's note: many of the answers are about removing Ubuntu from dual-boot but keeping Windows (which is a bit complicated), while other answers are about removing Ubuntu from single-boot (which is easy: basically just format the disk while installing Windows). The question as written is ambiguous between dual-boot or single-boot.


Let $k$ be the number of distinct ways of painting $6$ sides of a cube with $6$ distinct colors, where you would regard  two cube coloring the same If one can be obtained from the other by rotation, Then $k$ is    what i try  Number of distinct ways of painting a cube with $6$ distinct color is $\displaystyle 6\times 5\times 3!=180$  I have color Top side, can be done as $6$  and opposite face bottom  side with $5$ color Now arranging $4$ color in $4$ sides as $(4-1)!$  But my answer is wrong, Help me please

Consider the different ways to colour a cube with $6$ given colours such that each face will be given a single colour and all the six colours will be used. Define two such colourings to be equivalent if one will get from another just by rotation. Then what would be the number of inequivalent colourings?   The answer is given $30$. But I was trying to prove it by choosing the colour in the two opposite sides.   For example, first let us choose the colours on the two opposite sides in $^6C_2$ ways, then another two opposite sides in $^4C_2$ ways, and the leftover sides in $^2C_2$ ways. So, in total, we get $15 \times 6=90$, but I think I am triple-counting the situation or thinking it in a wrong way.  Please help.


I'll try to be short and simple.   I had Windows 8.1 (came with the computer) I tried to install Ubuntu I accidentally clicked continue with "erase disk and install" selected. Now everything is gone... My laptop doesn't even seem to have a factory image to reset to. No, I did not backup anything. :(   Ubuntu seems to be installed on my computer, and there is only one drive anymore (the now dedicated Ubuntu drive, I guess...).  Is there anyway I can undelete my hard disk? I just want my Windows 8 back...

I have a Toshiba satellite A-200 laptop with a Vista OS on it with 4 NTFS partitions  (C:) Vista  (D:) Entertainment  (E:) Work  (F:) Sources   and I wanted to start using Ubuntu instead. So I tried it first from the live CD and everything was OK and all the partitions were shown and working and so I decided to install Ubuntu to replace Vista on the (C:) drive. After I did that I can no longer find my folders and files on the (D:), (E:), (F:) partitions and the only file system that is shown is one 198 GB although my HDD is 320 GB.  I can't access the lost data on the remaining 120 GB which I hope is still there and not totally lost  I am now working from the live CD but I am unable to install testdisk. Can I recover the Vista partitions by the product recovery CD to get my laptop back to the factory settings? Can I recover the NTFS partitions using a recovery program for Windows or will that make the problem worse?   I need these data badly as I don't have a backup for them.


Being always confused, I would appreciate which is correct usage of "part of" or "a part of" in the following case with brief explanation as to how I should differ either. I have checked dictionaries and articles/speeches on the websites.  There are a lot of young people who want to be a part of the movement(or part of the movement).

When should I use "as part of", and when "as a part of"?


I am using QGIS to output data to a game engine, I use polygon centroids to find center points of polygons of houses to output to the game engine for house placement - now I'd like to take it one step further and get a correct(-ish) orientation of the house.   So my basic idea is to either straight up use the polygons to somehow get the angle relative to true north - or just find the longest side of a polygon house shape and then determine the azimuth/angle of that line - and preferably add this data as a new field to my polygon centroids.  I am still quite new to QGIS and GIS data in general but have been able to make a lot of use out of the GIS data I have.

Is there a possibility to determine the longest side of a polygon with QGIS? As I need to do that for hundreds of polygons I would prefer an automized method (like a plugin). So far my idea was:  transforming a polygon into a line cut it on the vertices measure the length here I became stuck, how to become the longest line without checking the whole bunch of lines one by one?


Question:      Let's say that I have $23$ people in my workplace. What is the probability that $2$ people in my workplace have the same birthday? Please answer in exact form with all decimal points that are implied.   I am sort of confused and would like to find the solution. If I could get a step-by-step solution, that would be great.   Thanks!

I found on this website  proof that the probability of two people in a room having the same birthday equates to 50% when when there are 23 people in the room  The only thing is, the explanation is too complicated for the average Middle School student to comprehend. So, my question is, is there any simplifies explanation of how this works? I tried Wikipedia but the explanations were even more complicated.  Thanks!


I've finished master studies in mathematics. Now I'm working on some papers, but I'm not so familiar with journals. I've submitted papers in some journals with impact factor, but it was rejected, while some other journals accept them (I doubt they accept anything for money). My question is: how can I find an appropriate journal for a modest paper?

There are some general questions on this site about judging the reputability of journals in general:     and     I am interested in answers specific to mathematics, that may not have been raised in the other questions.  I received the following email from the "American Journal of Pure and Applied Mathematics" ten days after submitting a paper online. How can I tell whether this is a reputable journal? In general, how can I tell whether a mathematics journal is reputable?      Dear Authors,      On behalf of the Chief Editor of the “American Journal of Pure and Applied Mathematics” we are happy to inform you that your article entitled ‘A possible approach proof to proof the Riemann Hypothesis” is accepted for publication in (Jan-June 2015).      Please send DD/Cheque for US $ 250.00 payable to ‘ Vijay Kumar Jha ‘ to our address.      Our address:   Vijay Kumar Jha   Managing Editor   c\o. ACADEMIC RESEARCH JOURNALS (INDIA)      4383/4A, Ansari Road, Darya Ganj, New Delhi-110002      (M) 08826561892      We thank you very much for your contribution and encourage you to continue submitting your future.      Yours sincerely,


I'm updating a listview on an Android app. It currently has an iOS-like (but apparently still material) "swipe" to delete functionality, where you swipe over, and then a delete button becomes visible. I am now setting it so that not just anybody can perform the delete action. Only specific users, or the user who created the list item entry.  My question is: is it better to prevent the swipe action if they do not have the authority? Or should I allow them to swipe and then if they tap the delete icon, show an alert dialog?

What is a good criterion or rule-of-thumb for determining when a control should be greyed-out and when should it be completely invisible?


I have read  about how to prevent line breaking in inline math. Now I wonder if it is possible to get a warning to the log for every breaking of an inline math formula.

Sometimes a line break inside inline math is acceptable and sometimes it detracts from the message. I'd like to be able to see exactly where such breaks (meaning any line break during inline math mode) occur in my final-minus-epsilon draft and decide if any action should be taken to rearrange sentence wording, etc. (based on my manual inspection of the instance). I know there are automated ways to prevent line breaking in inline math, but I don't want to do that. The document is huge, so it's not OK to just manually look through it for such breaks.  Is there a way to mark where these things occur? Ideally by line number in the log. But also OK would be some sort of visual or searchable signal that stands out in the PDF, if somehow that is easier.    Added later:  points out that \binoppenalty and \relpenalty are the badness contributors that matter. So can we log when these are used?


Often I find myself wanting to insert all columns except the IDENTITY column into a table, or select all columns apart from one.  I wonder if there's something in SQL Server like:  SELECT * EXCEPT SomeColumn FROM SomeTable   ?

Is there any RDBMS that implements something like SELECT * EXCEPT?  What I'm after is getting all of the fields except a specific TEXT/BLOB field, and I'd like to just select everything else.  Almost daily I complain to my coworkers that someone should implement this...  It's terribly annoying that it doesn't exist.  Edit: I understand everyone's concern for SELECT *.  I know the risks associated with SELECT *.  However, this, at least in my situation, would not be used for any Production level code, or even Development level code; strictly for debugging, when I need to see all of the values easily.  As I've stated in some of the comments, where I work is strictly a commandline shop, doing everything over ssh.  This makes it difficult to use any gui tools (external connections to the database aren't allowed), etc etc.  Thanks for the suggestions though.


X is r.v. on ($\Omega$,F,P) where $E[\left\lvert X \right\rvert^a] < \infty$. Prove $E[\left\lvert X \right\rvert^b] < \infty$ for all $0<b\le a$  How would I go about proving this using something in the realm of Lebesgue Integration or Domination thm. If I am off base with this please let me know. Having trouble even visualizing how to prove, would appreciate any help or hints.  edit: added abs value. sorry for that oversight!

Suppose $\mu(X)<\infty$. Show that if $\ f\in\ L^q(X,\mu)$ for some $1\le q<\infty$ then $\ f\in\ L^r(X,\mu)$ for $1\le r<q$   In the solution the assistant wrote this:  If $1\le r<q$ then $q/r\ge 1$. Let p be the dual exponent to $q/r$ (i.e. $\frac{1}{q/r}+\frac{1}{p}=1)$  then by Hölder Inequality  $\int_{X}|f|^rd\mu\le\underbrace{(\int_{X}|f|^qd\mu)^{r/q}}_{??????}(\int_X1^pd\mu)^{1/p}<\infty$  for me the middle part doesn't make sense (it is not the hölder inequality) can somebody show it ?  instead of this can't we say (only in this case) that   $\int_{X}|f|^rd\mu\le (\int_{X}|f|d\mu)^r$ then  $(\int_{X}|f|d\mu)^r\le ((\int_{X}|f|^qd\mu)^{1/q}(\int_X1^pd\mu)^{1/p})^r<\infty$  ?


(This question is not a duplicate because it is primarily concerned with how different zero dimensional objects/singularities with zero volume, are able to contain differing information on black holes such as their differing masses.) If a non-rotating black hole singularity is a zero dimensional point with zero volume, and if different black holes have different masses, then how can the differing masses be represented by the same singularity? There would seem to be no space to encode any differences at all between black holes of different masses? This would seem to suggest that non-rotating black holes have something larger than a singularity at their cores. Perhaps there is a state of matter with non-infinite density that is denser than a neutron star, or even a theorized quark star. If the "singularity" in a rotating black hole is a ring with zero dimensional thickness, and thus again zero volume, then the question is the same. How are the differences between differing black holes stored in an object of zero volume, differences such as mass and charge. Zero volume seems to preclude the storage of any information since there is no structure in which to store information. Where have I gone wrong in my understanding?

General relativity is expressed in terms of differential geometry, which allows you to do interesting things with the coordinates: multiple coordinates may refer to a single point, eg. the  has whole lines at the top and the bottom that correspond to the North and South poles, respectively; or a single coordinate may refer to multiple points, for example by using inverse geometry the origin refers to all the points infinitely far away.  So, is the singularity just a single point in the curved spacetime, or can it be a more extended object, described by a single coordinate?


We just upgraded our Windows Server 2003\SQL Server 2005 setup to Windows Server 2012/SQL Server 2012. Both configurations have a mirror with NO witness server.  On the old setup the transaction logs remained small, about 22 GB total. Now they're over 160 GB and the partition of the new server is getting full. I need to reduce the transaction log file sizes.  However, all of the descriptions I've read say to switch the recovery mode from Full to Simple then back to Full. This won't work because we have a mirror so the recovery model MUST remain in Full recovery mode. I couldn't change recovery modes unless I break the mirror.  What would be the best course of action to reduce the log file sizes? Should I go ahead and break the mirror, switch from Full -> Simple then back? Does anyone have experience with this kind of setup?

This one seems to be a common question in most forums and all over the web, it is asked here in many formats that typically sound like this:  In SQL Server -  What are some reasons the transaction log grows so large? Why is my log file so big? What are some ways to prevent this problem from occurring? What do I do when I get myself on track with the underlying cause and want to put my transaction log file to a healthy size?


is there any software, like lint for C, to check shell scripts ?  check    the syntax the compatibility with bash ksh etc...   online web service or installable as program  I don't want to run and debug. I am looking for static analisys, as lint for C.

I'm having some problems with some scripts in bash, about errors and unexpected behaviors. I would like to investigate the causes of the problems so I can apply fixes. Is there a way I can turn some kind of "debug-mode" for bash, to get more information?


It feels like the firing animations take a ridiculously long time, and although I don't have hard data, I think they take the majority of my missions. The sniper animation is especially egregious, I don't want to watch a guy take 5+ seconds to line up a shot and then miss it.

XCOM Enemy Unknown is a beautiful game, but you can only see every 5 second animation so many times before it becomes repetitive and self-indulgent. Is there a way to make the animations go faster or speed combat up in some other way, so that I can spend more time strategically exterminating aliens and less time watching my operatives shoot their guns?


Across as adverb cited from :  1 from one side to the other side It's too wide. We can't swim across. The yard measures about 50 feet across. 2 in a particular direction towards or at somebody/something When my name was called, he looked across at me. 3 across from opposite There's a school just across from our house.  I'm trying to rewrite them into:  It's too wide. We can't swim over. The yard measures about 50 feet over. When my name was called, he looked (over / away) at me. There's a school just over our house.  Are these adapted sentences idiomatic? Any nuances between them and the original ones?

Dusk closed across the house, sweeping its long shadows over   the plain, the horizon merging into the sky.   I cannot conceive what it looks like.  Are close and sweep used figuratively here? And are across and over used interchangeably here?


My iPad Pro with iOS version 11++ has been disabled and I only get a screen : "iPad is disabled. Connect to iTunes.". It need to be restored in order to function again properly but all data would be erased. How can I access the data while it is disabled ?

Trying to turn on my kids' iPad which has been off for a few months.  Tried several of my 'usual' passcodes, but iPad became 'disabled' before I could try them all.  Now it's "iPad is disabled, connect to iTunes"  Connecting to iTunes via hold-home-and-plug-in-USB pops up iTunes with "Restore" or "Update".  Do NOT want to lose all data, there are probably photos on there that are not backed up.  Is there ANYTHING I can do?  I'm not even sure which version of iOS is on there, but it's 8.something...  If I could just get a few more attempts to enter PIN, I would figure it out eventually.  Can I jailbreak it in this condition? Somehow pull the data before Restoring/Updating?  HELP!


I would like to put a full width picture on a front cover page using the Tufte-Latex class. How can I do it? This is my MWE:  \documentclass[openany, justified]{tufte-book} \usepackage[utf8]{inputenc} \usepackage{graphicx}  \newsavebox{\titleimage} \savebox{\titleimage}{\includegraphics[height=15\baselineskip]{garden.jpg}}  \title[Hyper Simple]{%   \setlength{\parindent}{0pt}% A title \par \par \vspace{1cm}   \usebox{\titleimage}} \author{My name} \publisher{Exhibition Catalog}  \begin{document} \frontmatter % r.3 full title page \maketitle \chapter{First chapter} \end{document}

Can anyone share his or her experience on designing a book cover? I just finished writing my "Awk One-Liners Explained" e-book and now I am designing the cover. I tried \maketitle and the result was pretty ugly (see screenshot below). I'd appreciate any tips on designing book covers.


Error mounting /dev/sda1 at /media/mdnazmossakib/01D189A576840DF0: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sda1" "/media/mdnazmossakib/01D189A576840DF0"' exited with non-zero exit status 14: The disk contains an unclean file system (0, 0). Metadata kept in Windows cache, refused to mount. Failed to mount '/dev/sda1': Operation not permitted The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option.   What is the solution to this? It was working fine, but this suddenly happened. Help me to solve this.

Whenever I boot Ubuntu, I get a message that it cannot mount my windows partition, and I can choose to either wait, skip or manually mount.  When I try to enter my Windows partition through Nautilus I get a message saying that this partition is hibernated and that I need to enter the file system and properly close it, something I have done with no problem so I don't know why this happens.    Here's my partition table, if any more data is needed please let me know.     Device Boot      Start         End      Blocks   Id  System /dev/sda1            2048    20000767     9999360   83  Linux /dev/sda2        20002814   478001151   228999169    5  Extended /dev/sda3   *   478001152   622532607    72265728    7  HPFS/NTFS/exFAT /dev/sda4       622532608   625141759     1304576   82  Linux swap / Solaris /dev/sda5        20002816   478001151   228999168   83  Linux


A coin toss is referred as IID in several websites. What I want to know that if I'm understanding the concept right.  If X denote a random variable which means the "result of a coin toss" then $x_1, x_2, ... , x_n$ are the results of repeated coin tossing. Are $x_1, x_2, ... , x_n$ IID? If yes, how can observations be variables?  Or are $X_1, X_2, ... , X_n$ all considered as random variables if we want to consider them IID? How can a random sample be IID?

I have been facing hard time understanding meaning of "random sample" as well as "iid random variable". I tried to find out the meaning from several sources, but just got more and more confused. I am posting here what I tried and got to know:  Degroot's Probability & Statistics says:     Random Samples / i.i.d. / Sample Size : Consider a given probability distribution on the real line that can be represented by either a p.f. or a p.d.f. $f$. It is said that $n$ random variables $X_1 , . . . , X_n$ form a random sample from this distribution if these random variables are independent and the marginal p.f. or p.d.f. of each of them is $f$. Such random variables are also said to be independent and identically distributed, abbreviated i.i.d. We refer to the number n of random variables as the sample size.   But one of the other statistics book I have says:       In a Random Sampling, we guarantee that every individual unit in the population gets an equal chance(probability) of being selected.   So, I have a feeling that i.i.d.s are elements that construct random sample, and the procedure to have random sample is random sampling. Am I right?   P.S.: I am very confused about this topic, so I will appreciate elaborate reply. Thanks.


I am trying to install packet tracer. I installed java and than packet tracer, but when I'm launching it from terminal, I see the output as "Starting packet tracer 7.1.1" and nothing happens. When I'm searching it, I cant see packet tracer installed!

I have downloaded and extracted the packet tracer file, then I used this command as root  chmod +x install   then I ran (as root)  ./install    Then I used this command   ./set_ptenv.sh   but whenever I run this command   packettracer    it just doesn't start


How to convert char to ASCII and display in textbox in C#?  For Eg :  i have char a and i want to convert this to ASCII-code 95 and display it in textbox.  noted : tools =  visual Studio express edition 2010

Here's the problem:  In C# I'm getting information from a legacy ACCESS database. .NET converts the content of the database (in the case of this problem a string) to Unicode before handing the content to me.  How do I convert this Unicode string back to it's ASCII equivalent?   Edit Unicode char 710 is indeed MODIFIER LETTER CIRCUMFLEX ACCENT. Here's the problem a bit more precise:     -> (Extended) ASCII character ê (Extended ASCII 136) was inserted in the database.  -> Either Access or the reading component in .NET converted this to U+02C6 U+0065     (MODIFIER LETTER CIRCUMFLEX ACCENT + LATIN SMALL LETTER E)  -> I need the (Extended) ASCII character 136 back.    Here's what I've tried (I see now why this did not work...):  string myInput = Convert.ToString(Convert.ToChar(710)); byte[] asBytes = Encoding.ASCII.GetBytes(myInput);   But this does not result in 94 but a byte with value 63... Here's a new try but it still does not work:  byte[] bytes = Encoding.ASCII.GetBytes("ê");    Soltution Thanks to both  and  for pointing in the right direction I solved the problem .


I want to put a grid in the background of every page (for use in classroom). I found the package pagegrid. I can change the color of the red/blue grid, looks beautiful, but I need to change the color of the help lines to light-gray, otherwise it's too dark to use for my students.  Another possibility would be to get rid of the helplines alltogether, but this didn't work either.   MWE:   \documentclass[a4paper,11pt]{article} \usepackage[step=5mm,firstcolor=gray,arrows=false]{pagegrid} \pagegridsetup{top-left} \begin{document} Test \end{document}

Is it possible to have graph paper as an underlay and then run the usual latex commands?  For instance, instead of having a latex document written on a blank page, is it possible for the page to be graph paper instead?  I'm a tikz novice, but I'm proficient enough to do what I need to do, but grids and tikz and enumerated lists, don't play nicely together. If the paper was graph paper to begin with at least one of my problems would be solved.  I've found partial workarounds, although nothing definitive: one that allows me to have graph paper but only on the first page, and it overlays my title anyway - I use maketitle for that.  Any suggestions?


I created an object in JavaScript and stored some information in the object. I searched a lot for solution, but did not find any solution. I want to get the count/length of object.  Javascript Code: productDetail = new Object(); productDetail["Code"] = "A104"; productDetail["ProductName"] = "Keyboard"; productDetail["UnitPrice"] = 10; productDetail["Dealer"] = "AMD";

I have a JavaScript object. Is there a built-in or accepted best practice way to get the length of this object? const myObject = new Object(); myObject["firstname"] = "Gareth"; myObject["lastname"] = "Simpson"; myObject["age"] = 21;


I have two tables in the database tbLicence and tbJurisdiction tbJurisdiction has two feilds  - Jurisdiction as PK - JurisdictionX as Jurisdiction Name   tbLicence has three feilds  - Licence as PK - AgentId  - Jurisdiction   Let's us say  tbJurisdiction contains values as  - 1 - Alabama - 2 - Florida - 3 - New York - 4 - Mexico - 5 - New Jersey   tbLicence contains values as  - 1 - 224 - Florida, New York - 2 - 304 - New Jersey, Alabama   Now I want to fetch Jurisdiction and JurisdictionX on the basis of AgentId let us say 224  I want the final output should be like  - 2 - Florida - 3 - New York   I have tried the below query     SELECT L.Jurisdiction,    L.JurisdictionX    FROM   tbJurisdiction L    Join tbLicence P on     Jurisdiction    Where P.AgentId =@AgentId;   Its not working  Please help me !!!

Using SQL Server, how do I split a string so I can access item x?  Take a string "Hello John Smith". How can I split the string by space and access the item at index 1 which should return "John"?


Basically, as it says in the title I require an answer on why is it so that if a function has a right inverse then it is surjective. I am currently self studying abstract algebra and please take that in mind.

We have the sets $X,Y$ and $f:X\to Y, \ g: Y\to X $      Prove if $f$ has a right inverse function: $f\circ g=id_Y$ $\iff$ $f$ is onto $Y$ (surjective).   $\Leftarrow \forall y\in Y : \exists x\in X$ then $f(y)=x$ I need to show that $f\circ g(x)=x$ but I don't know how.  I have no clue on to start in the other direction.   BTW, I found below similar question but they're either not quite the same as this one or I didn't understand the answers:


That's really embarrassing, however I need to ask it. I could not prove that the normed space    $\langle \mathscr{C} [0, 1], \| \cdot \|_1 \rangle $ is complete (as a metric space), where $\| f\|_1 = \int_0^1 |f(x)|dx$. I don't really know how to explicit a continuous functions as a limit of a Cauchy sequence. I tried to prove that the pointwise limit (of the Cauchy sequence) have just a finite number of discontinuities (I don't know if it's true) and then approximate it by a continuous function.  Thanks in advance.

Consider $C([0, 1])$, the linear space of continuous complex-valued functions on the interval $[0, 1]$, with the norm  $$\displaystyle\lVert f\rVert_1 = \int_0^1 \lvert f(x)\rvert \,dx.$$  I have to show that $C([0, 1])$ is not complete with respect to this norm. I have found the following example from a book.  Let $f_n \in C[0,1]$ be given by  $$f_n(x) := \begin{cases}  0   & \text{if $0 \le x \le \frac1{2}$}\\  n(x-\frac{1}{2}) & \text{if $\frac {1}{2} < x \le \frac {1}{2} + \frac {1}{n}$}\\  1              & \text{if $ \frac {1}{2} + \frac {1}{n} <x \leq 1 $} \end{cases}$$  How to prove that $f_n$  is a Cauchy sequence with respect to $\lVert \cdot\rVert_1$?   If I use basic definition then I have to prove that $\lVert f_n - f_m\rVert_1 < \epsilon$ $\forall n, m > N$. But I am finding it difficult to prove this.  Please help me to understand how to prove that $f_n$ is Cauchy sequence in $C([0, 1])$.  Thanks


How do you prove that r(2, n) = n in Ramsey numbers?  We have to show that r(2,n)<=n and that r(2,n) >= n.

Verify that $R(p,2) = R(2,p) = p$, where $R$ is the Ramsey number   It just seems obvious that $R(p,2) = R(2,p)$.  But why do  $R(p,2)$ and  $R(2,p)$ both equal p?


OK..I have another sub-panel question.  My sub has a 50 amp gfci that powers (old) spa.  Currently this sub panel has a single neutral/ground bar.  This bar is bonded, (screw is in), to the metal enclosure.  There is an in-ground ground bar, of which a ground wire connects it to the neutral/ground bar.   There are three wires from the main, two hot and one neutral.  This is how the sub is configured and powered the (old) spa.  I have a new spa.  I know this configuration will work for the new spa.  I ask for your specific guidance on ensuring I end up with the correct/compliant configuration.     **If I need to run a ground wire from main to sub.  Can it be run separately outside of any conduit.

I have a sub panel on back of house. From main in garage is three wire.  2 hot one neutral.  NO GROUND WIRE.  Sub has a single bar used as neutral and grounds.  Its bonded to case (Screw in).  I will add a ground only bar, a ground to earth rod and wire them together.  I cannot get the snake all the way through the conduit to pull a ground wire.    Can I run a separate ground wire alongside the conduit to the sub?  ===========================================================================  Update/clarifications:  Thank you Speters.  ArchonOSX, I understand there should be a common ground back to the main, I do not have that. Currently (pre-existing),  I have a 3wire 50 amp gfci breaker for a spa in this SUB.   Its the only circuit. I was advised to Isolate the neutral bar and add a ground bar, bonding it to earth;  Where new circuits utilize the ground bar. In this config would I be protected and no SUB/main panel metal become  energized if a short occurred?


Why is it that the uncertainty principle is not applicable to macroscopic objects? Specifically, at which scale does the uncertainty principle does not work? And also why? Why doesn't it work for macroscopic objects?

Many introductory quantum mechanics textbooks include simple exercises on computing the de Broglie wavelength of macroscopic objects, often contrasting the results with that of a proton, etc.  For instance, this example, taken from a textbook:     Calculate the de Broglie wavelength for      (a) a proton of kinetic energy 70 MeV      (b) a 100 g bullet moving at 900 m/s   The pedagogical motivation behind these questions is obvious: when the de Broglie wavelength is small compared to the size of an object, the wave behaviour of the object is undetectable.  But what is the validity of the actual approach of applying the formula naively? Of course, a 100g bullet is not a fundamental object of 100g but a lattice of some $10^{23}$ atoms bound by the electromagnetic force. But is the naive answer close to the actual one (i.e. within an order of magnitude or two)? How does one even calculate the de Broglie wavelength for a many body system accurately?


I'm having a hard time hearing the name of Peggy's husband she names. I'm not the greatest at spelling but it sounds like his name is something like: Emanhu Winter?  Here's the scene if anyone can help, he's named at 1:40:

When Steve Rogers visits Peggy Carter, she has a family photo on her nightstand and says that she married someone after Cap disappeared. Who did she marry?


I recently flagged a closed question for moderator attention because it was off-topic and would have been better suited to another SE site. However, my flag was declined, and I was told "it's too old to migrate". So how long is a question eligible for migration? I can't seem to find the rule for this. I would like to know so I don't waste moderators' time in the future by filing impossible requests.  Note that the fact that the question was already closed is important here. Normally, if a question is off-topic, I would choose an "off-topic" flagging option. If the question can still be migrated, there is an option called "This question belongs on another site in the Stack Exchange network" under "Flagging > Closing > Off-Topic". If the question is too old to be migrated, this option doesn't appear. However, if the question is already closed, the entire "Off-topic" flagging menu is unavailable because it's part of the "Closing" flag menu.

I posted a question which was closed as off-topic and it seems like it could fit on another site in the network. How can I go about moving it there?   What is migration? When can a question be migrated, and who can migrate it? When should I consider migration, and when is it inappropriate? What causes a migration to be blocked and what happens after? What causes a migration to be rejected and what happens after? Anything else I should know about migration?


First of all, sorry for opening a new question about it, but I'm curious to understand:   John Hughes claims that $\langle p,q \rangle =0$ (in the end of his answer)  Why is it true?

Let $V$, a vector space over $\mathbb{F}$ and $W_1,W_2 \subseteq V$ such that $W_1 \oplus W_2 = V$. For $i=1,2$, let $\langle , \rangle $ on $W_i$. Prove that there is a unique inner product on $V$ such that:  $W_2 = W^\perp_1$ For $i=1,2$ and for all $v,u\in W_i$: $\langle v, u \rangle = \langle v, u \rangle _i$   Uniqueness: Let $v = w_1 + w_2$ and $u = w_1' + w_2'$ $$\langle u, v \rangle_V = \langle w_1,w_1' \rangle + \langle w_1,w_2' \rangle + \langle w_2,w_1' \rangle + \langle w_2,w_2' \rangle = \langle w_1,w_1' \rangle  + \langle w_2,w_2' \rangle $$ So the inner product is determined uniquely by $\langle, \rangle_i $ for $i=1,2$. How do I show the existence of such inner product?


I am receiving the below error when the batch is executing. This is not happening all the time. This happens only at certain times.     uncommitted work pending. Please commit or rollback before calling out   The batch that runs performs deletion of some child records based on the flag for the passed in parent record in the batch. Then it makes a callout to receive token and then another callout to send both parent and child record. For each callout, whatever response is received that is stored in a list of log object. Then after processing all the records for callout, insert of the log object is done. Then the processed parent and child records flag is reset by update.  I have scheduled this batch to run every 3 minutes. In that only some logs have success and other logs have empty responses because of the error. Can someone help me on this?

I have same exception can please   The previous post issue is resolved.  Exception: :System.CalloutException: You have uncommitted work pending. Please commit or rollback before calling out  Visualforce Page   <apex:page controller="Controller" action="{!init}" showHeader="false" sidebar="false">     <center>         <apex:pageBlock title="Request Listener"></apex:pageBlock>               </center> </apex:page>   Controller :            PUBLIC with sharing class Controller {        PUBLIC String fromNumber      = ApexPages.currentPage().getParameters().get('From');     PUBLIC String toNumber        = ApexPages.currentPage().getParameters().get('To');     PUBLIC String body            = ApexPages.currentPage().getParameters().get('Body');        PUBLIC PageReference init()     {                    System.debug('From Phone Number :' +fromNumber);         System.debug('To phone NUmber :' + toNumber);         System.debug('Message Body :' + body);          TwilioRestClient Client = TwilioAPI.getDefaultClient();                                                                SYSTEM.DEBUG('FROM AND To  Number is NOT NULL');                      String formattedNumber='+919876543210';                 IF(body != NULL)                 body = body;             ELSE                 body = '';             Case c = NEW Case (Subject = formattedNumber,Description = body,Origin = 'Phone');             INSERT c;                               Map<String,String> params1 = new Map<String,String>             {                'To'   => fromNumber,                'From' => '+1908280****',                'Body' => 'Conformation to customer'             };             TwilioMessage message = client.getAccount().getMessages().create(params1); /* Valid conformation SMS sent to the Customer.*/                                            return null ;     } }   While loin as admin then click preview on visualforce page executed but case is not created.I have checked the the debug log it throw the exception.


I have noticed that several website news items are indexed immediately by Google. Even questions posted on stackexchange.com are indexed by Google within minutes. Can someone tell me how i can do that with the website which has frequent news items on website.  How can i achieve this with otherwise with has frequent news or press releases posted.

I have a new website with 140k pages, according to my sitemaps.  After submission of my sitemap index to Google, the Googlebot has started crawling the site a couple of hours ago, and at a steady pace, but it's doing so too slowly: roughly one request per minute.  At such rate, it'll take 100 days for the site to be indexed!  Is there a way to increase the rate?  Why does all Google documentation suggest that they don't recommend changing the crawl rate, and that changing the crawl rate will only make the crawling slower?


Let n ∈ $\mathbb{N}$ be a natural number, an ordered set of positive integers $(λ_{1},...,λ_{k})$ such that $λ_{1}\,+ \, ... \, + \, λ_{k} = n$ is called a composition for n ∈ $\mathbb{N}$. These integers are not necessarily distinct. Show that the number of possible compositions for n ∈ $\mathbb{N}$ is $2^{n−1}$.  Example: the number $n = 4$ has the following 8 compositions $(4),(3, 1),(2, 2),(2, 1, 1),(1, 3),(1, 2, 1),(1, 1, 2),(1, 1, 1, 1)$.

How to evaluate the number of ordered partitions of the positive integer $ 5 $?  Thanks!


I have a feeling that this is a stupid question, but googling around I haven't found an answer to it.   Simply: What does it mean if a multiple regression model is significant but none of the individual predictors are significant? There are between 5 and 10 predictors in the model.   I would imagine that it's because of the high number of predictors in the model. One of the predictors almost passed the threshold of significance (p = .06). Most of the predictors, when isolated in separate simple regression models with the same independent variable, have significant p-values. In other words, the simple regression model with predictor A and variable Z is significant, the simple model with predictor B and variable Z is significant, etc., but the multiple regression model with predictors A, B, etc., and variable Z is non-significant.   My other thought would be multicollinearity, but I tested all of the assumptions, and the multiple regression model meets them. In particular, I tested for multicollinearity with the “vif()” function in R. As far as I understand, a VIF value over 5 or 10 for any predictor indicates a problematic level of multicollinearity. For this multiple regression model, none of the predictors exceeded a VIF value of 5. If it matters, the VIF values for each variable were: 2  2  4  4  1  2  1.5  and 3.5.   For theoretical reasons, I would expect there to be an overlap between the predictors, because there are theoretically causal relationships between some of the predictors that were used.   Thanks in advance. :)

In a multiple linear regression, why is it possible to have a highly significant F statistic (p<.001) but have very high p-values on all the regressor's t tests?  In my model, there are 10 regressors. One has a p-value of 0.1 and the rest are above 0.9    For dealing with this problem see the .


I have tried and tried but cannot for the life of me see how one equation follows onto the other... can anybody help??  $$\Omega(\theta)=-b.\coth(\operatorname{arsinh}(\exp a\theta . \sinh(c_0)))$$  $$\implies \Omega(\theta)=\sqrt(c_1.\exp -2a\theta + b^2)$$  Note that: $$C_0=-\operatorname{arcoth}\left(\frac{\Omega_0}{b}\right)$$  Eichberger quotes (at the bottom of page 5) "By inserting (11) into (8), using identities of the hyperbolic transcendental functions and carefully observing ± signs, we obtain Ω as a function of θ."

I have tried and tried but cannot for the life of me see how one equation follows onto the other... can anybody help??   $$\Omega(\theta)=-b \coth(\operatorname{arsinh}(e^{a\theta}   \sinh c_0 ))$$  $$\implies \Omega(\theta)=\sqrt{c_1 e^{-2a\theta} + b^2}$$  note that: $c_0=-\operatorname{arcoth}\left(\frac{\Omega_0}{b}\right)$  Eichberger quotes (at the bottom of page 5) "By inserting (11) into (8), using identities of the hyperbolic transcendental functions and carefully observing $±$ signs, we obtain $Ω$ as a function of $θ$."


I just installed Ubuntu 20.04. As far as I can tell, there seems to be at least 3 shortcuts to access the Activities menu: Super, Super+S and Alt+F1.  I also tend to switch between "en-us" and "pt" keyboard layouts often with the Super+space shortcut.  The problem is, when I press Super+space to switch to the Portuguese layout, the Super shortcut stops working. Super+S and Alt+F1 still work though, but they're not as handy.  When I press Super+space again to switch back to en-us, the Super shortcut starts working again.  Any idea why this might be happening? I suspect something else also has Super+space registered as a shortcut for a different purpose, but I don't know where to look.

I just updated to Ubuntu 20.04 LTS and my super key has lost its main functionality. Previously in Ubuntu 18.04LTS, I was able to click the super key and the applications drawer would show. Now it doesn't do that. I can still open it by clicking super+a but it's annoying that it doesn't do that.  I restarted my machine and still nothing.


Let $ f $ be a function such that $ f'' $ exists at $ x=0 $. Is it true that : $$ \lim_{x\to0}\frac{f'\left(x\right)-\frac{f\left(x\right)-f\left(0\right)}{x}}{x}=\frac{f''\left(0\right)}{2} ~~?$$ Im pretty sure that in order for this to be true, $ f'' $ should be continuous, which is not given. But I'm struggling to find a counterexample. I need to find a function that is twice differentiable, but $ f'' $ is not continuous (assuming I understood the situation). I'd appreciate some help. Thanks in advance.

$$\lim_{x\to0}  \frac{f'(x) - \frac{f(x)-f(0)}{x}}{x} = \frac{f''(0)}{2}$$  I have been thinking about this for a bit of time now, but I'm not getting anything. What I have done: write $f'(x)$ as it's defined: $$f'(x) = \lim_{h\to x}\frac{f(h) - f(x)}{h-x}$$  Now we can write:  $$\lim_{x\to0}  \frac{f'(x) - \frac{f(x)-f(0)}{x}}{x} = \lim_{x\to0}  \frac{\lim_{h\to x}\frac{f(h) - f(x)}{h-x} - \frac{f(x)-f(0)}{x}}{x}  $$  I have tried lots of algebraic manipulation after this, but nothing has come out so far. Could someone steer me in the right direction?  EDIT: I just opened Rudin, which has a similar question that indicates that l'Hopital's should be used. Indeed:  $$\lim_{x\to0} \frac{f'(x) - \frac{f(x)-f(0)}{x}}{x} = \lim_{x\to0} \frac{xf'(x) - f(x)-f(0)}{x^2}$$  We can apply l'Hôpital: $$ \lim_{x\to0} \frac{xf'(x) - f(x)-f(0)}{x^2} = \lim_{x\to0}\frac{f'(x) + xf''(x) - f'(x)}{2x} = \frac{f''(0)}{2}$$  EDIT #2Using Taylor's theorem, as suggested in the comments. We choose to perform the Taylor expansion of $f(0)$ at $x_0 = x $. Then: $\exists c $ between $x$ and $0$ such that:  $$f(0) = f(x) - xf'(x) + \frac{x^2f''(c)}{2} \implies \frac{f''(c)}{2} = \frac{f'(x) - \frac{f(x)-f(0)}{x}}{x}   $$  As $x\to 0$, $c\to 0 $ and we have   $$\lim_{x\to0}  \frac{f'(x) - \frac{f(x)-f(0)}{x}}{x} = \frac{f''(0)}{2}$$


E/: Cannot load libgui-plugin D/AndroidRuntime: Shutting down VM E/AndroidRuntime: FATAL EXCEPTION: main     Process: com.example.ayushjain.myapplication33, PID: 24308     java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.ayushjain.myapplication33/com.example.ayushjain.myapplication33.Main2Activity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2911)         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2989)         at android.app.ActivityThread.-wrap11(Unknown Source:0)         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1688)         at android.os.Handler.dispatchMessage(Handler.java:106)         at android.os.Looper.loop(Looper.java:164)         at android.app.ActivityThread.main(ActivityThread.java:6753)         at java.lang.reflect.Method.invoke(Native Method)         at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:482)         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)      Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference         at com.example.ayushjain.myapplication33.Main2Activity.onCreate(Main2Activity.java:37)         at android.app.Activity.performCreate(Activity.java:7041)         at android.app.Activity.performCreate(Activity.java:7032)         at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1231)         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2864)         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2989)          at android.app.ActivityThread.-wrap11(Unknown Source:0)          at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1688)          at android.os.Handler.dispatchMessage(Handler.java:106)          at android.os.Looper.loop(Looper.java:164)          at android.app.ActivityThread.main(ActivityThread.java:6753)          at java.lang.reflect.Method.invoke(Native Method)          at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:482)          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I have made the svg file and imported and then converted to curve. As i have make with the red is my original mesh and the below is unmark bevel mesh.  I want my mesh to be bevel from the center and it should not created space or gap as seen the below mesh. The mesh should make bevel from the center mark in green.  Im i doing correct way or is there any other way or how should i make the bevel without creating gap or space in middle of mesh.  As the mesh is present same shape should be bevel from the center.    result    Reference image

How can I make a bevel, like in the "Gibson," for my personal inscription? Is there an automatic method to do so?


He rides a bike reading the book. (with no comma between bike and reading)    He rides a bike, reading the book. (with a comma between bike and reading)       In the sentence above, What is the difference in the sentence 1 (no comma) and 2 (with comma)?

There are three sentences.        He watched TV reading the book. (with no comma between TV and reading)     He watched TV, reading the book. (with a comma between TV and reading)     He watched TV to read the book. (with 'to' between 'TV' and 'reading')      I think that the intervals in the sentences vary by comma or to.  For example, I think that there is no time interval between 'the verb' watch and read in the first sentence (He watched TV reading the book.)  And there is some time interval between 'the verb' watch and read in the first sentence (He watched TV, reading the book.) And there is so much time interval between 'the verb' watch and read in the first sentence (He watched TV to read the book.)  Am I right?


My book is asking me to show that every matrix of the form $A=\begin{pmatrix}0&a\\0&b\end{pmatrix}$ has a $LU$-factorization and to show that even if $L$ is a unit lower triangular matrix that the $LU$ factorization is not unique.  Doesn't this contradict the theorem for $LU$ factorization which says for a matrix $A$: If the leading principal minors of $A$ are all nonsingular, then $A$ has an $LU$ decomposition.  Clearly, the leading principal minors of $A$ are singular.  What does this mean? What is the $LU$ factorization?

How can I show that every matrix of the form $\begin{bmatrix}0& x\\0 & y\end{bmatrix}$ has an $LU$ factorization and that even if $L$ is unit lower triangular there is not a unique factorization?  I am completely stuck. Any ideas would be greatly appreciated


I am trying to typeset something in Polish. Unfortunately one letter mysteriously disappears - but only when it is the last in a word. When I add a character ('a' in the example below) right after the missing one, it shows up again. Can someone explain that?  Here is the code:  \documentclass[12pt, a4paper]{article} \usepackage{polski} \usepackage{xltxtra} \setlength\parindent{0pt} \usepackage{soul}  \begin{document} Wnoszę o głosowanie\\ Wnoszęa o głosowanie\\  \st{Wnoszę o głosowanie}\\ \st{Wnoszęa o głosowanie}\\   \end{document}

I'm using soul to letterspace headings in a Hungarian document and compiling it with lualatex.  For some reason soul drops some of the accented letters at the end of a word, but not all. In the example below, only ő and ű are affected:  \documentclass{minimal} \usepackage{fontspec} \setmainfont[Ligatures = TeX]{TeX Gyre Pagella} \usepackage{soul} \begin{document} \noindent \so{áll llá ÁLL LLÁ}\\ \so{íll llí ÍLL LLÍ}\\ \so{űll llű ŰLL LLŰ}\\ \so{őll llő ŐLL LLŐ}\\ \so{üll llü ÜLL LLÜ}\\ \so{öll llö ÖLL LLÖ}\\ \so{úll llú ÚLL LLÚ}\\ \so{óll lló ÓLL LLÓ}\\ \so{éll llé ÉLL LLÉ} \end{document}


Frequently my Ubuntu 14.04 server filesystems changed to read-only.  I ran fsck and rebooted which solved my issue.   How to fix the issue permanently?  end_request: I/O error, dev sda, sector 65563152 Buffer I/O error on device sda5, logical block 1313602 lost page write due to I/O error on sda5 Aborting journal on device sda7-8. Buffer I/O error on device sda5, logical block 1313603 lost page write due to I/O error on sda5 Aborting journal on device sda6-8. Aborting journal on device sda5-8. EXT4-fs error (device sda5) in ext4_reserve_inode_write: Journal has aborted EXT4-fs error (device sda6): ext4_journal_start_sb: Detected aborted journal EXT4-fs (sda6): Remounting filesystem read-only EXT4-fs error (device sda5): ext4_journal_start_sb: Detected aborted journal EXT4-fs (sda5): Remounting filesystem read-only   let me know for more info  thanks

I've run across (personally or by proxy) a bunch of storage media that exhibited physical problems during their life. Hard disks, solid state drives and other flash storage media all fail after some time. The situation is worse with USB flash drives and flash cards because of the large amount of suppliers with inferior flash cell and flash controller quality.  How can I reliably detect if a storage drive suffers from physical damage?  Note that this question isn't about file system integrity (which can be checked with ).


Many employees of public companies have trading restrictions to trade their employer's stock because they have inside knowledge. For simplicity let's assume I'm an Apple employee and only allowed to trade in the month after a quarterly report has come out. I also have investments (e.g. 401k, IRA) in various mutual funds and ETF, some of which also hold and trade Apple stock. When I buy/sell any of these funds or the funds themselves buy/sell Apple stock, I'm technically trading Apple stock outside the legal trading window. Is this a violation of SEC rules? I'm guessing it's fine, since the Apple portion of my direct or indirect trades is heavily diluted by the other holdings of the ETF but I would like to know :  If you are legally restricted by trading a specific stock, can you still buy, sell, or own mutual funds or ETFs that trade/hold this specific stock ? If the answer to 1) is "mostly yes", what are some specific circumstances or trigger points that would make it a "no"? If the answer is "no", what is the expectation for Apple employees to manage their investments? Finding funds or ETFs that don't hold any Apple is kind of difficult :-)  @mods: If this is a better fit for  feel free to move it or I can move it myself. Thanks !

Let's say I own shares in the MSCI World ETF. Company X, where I am an employee, is currently not part of it. What happens when in ie a year Company X gets added to the ETF - Is my owning stock in it considered insider trading? If so, would it mean I need to sell my existing share in this ETF or should no longer buy more of it?


I would like to know if there is a way to even possibly populate field value automatically for a column based on the condition of other columns. Not sure what the best way to explain but to provide an example here:  Essentially, I have an attribute table with 5 columns. I've established the domain in which the values can only be numbers (1 or 2). Ideally I would like to create a sixth column in which will auto populate based on the values from the previous 5 columns. The condition is this, if there is a value 2 in any of the columns the sixth column would be valued at 2. If all columns were listed at 1 then the sixth column would be 1.  I do not wish to auto generate this manually. I would like it in a way in which when the first 5 columns are populated, the sixth value will auto generate.

When editing I want to be able to change the attributes of one field and upon doing this allow for the automatic update of another field in the same attribute table.   Essentially I have one layer with a code, description and legend information.   I would like to be able to edit the code and have the description and the legend information update with this edit with its correct description and legend information.   Is there any way to do this within ArcMap's tools or an associated script?


Consider the following sentence:     The SuperAPI is the API that can be used to configure a Higher-Order   model.   When this sentence exists in a Microsoft® Office 365 Word document, the grammar checking functionality flags the fragment, "that can be used," as passive.  How would I rewrite this as an active-voice sentence?  However,  does not complain about this.  I see plenty of examples using the sentence fragment, "that can be used," in describing the proper grammatical formation of active-voice phrases!  (For example, see  in which exists, "Semicolons are one type of punctuation that can be used to link two independent clauses together."  I believe ignoring the warning doesn't diminish the strength of the containing document.  If it does, what rule guides me in rewriting this into an active-voice version?

Whenever I create a document in Microsoft Word, it complains about a lot of my sentences being in passive voice. But, when I read that sentence aloud, it sounds fine to me. I am not sure if it is just me and will a statement in passive voice sound strange to a native speaker?  So, my question is, is it considered bad form to use passive voice generally? Or in some specific cases like written communications only?  Edit: If it is ok to use passive voice, then why does MS-Word complain?


I'm playing with the 'is' operator in the interactive shell when I encountered an odd behavior with the below code:  It goes as expected at first:  >>> x = 11  >>> y = 11  >>> x is y  True   But when I tried this one:  >>> x = 987456  >>> y = 987456  >>> x is y  False   After further tries using id() function, I noticed that integers >256 points on the same object while others are not. I also noticed that this behavior only occurs in the python interactive shell. What's with this behavior?

My  has failed me.  In Python, are the following two tests for equality equivalent?  n = 5 # Test one. if n == 5:     print 'Yay!'  # Test two. if n is 5:     print 'Yay!'   Does this hold true for objects where you would be comparing instances (a list say)?  Okay, so this kind of answers my question:  L = [] L.append(1) if L == [1]:     print 'Yay!' # Holds true, but...  if L is [1]:     print 'Yay!' # Doesn't.   So == tests value where is tests to see if they are the same object?


Which two operator overloading methods can you use in your classes to support iteration?

How would one create an iterative function (or iterator object) in python?


Brazil have Neymar. Argentina have Messi. Portugal have Ronaldo. Germany have a team!   I read this on Facebook, and someone said the singular "has" is supposed to be there instead of the plural "have" in all cases within the quoted phrase.  I got myself thinking, though, whether the plural wouldn't be correct, making each country's name a collective of the people that are part of it, or perhaps a collective reference to the national team of each country in this specific case.   I've seen uses such as     the police are conducting an investigation   making the noun "police" a collective of all people within a police force, but I'm not sure these kinds of usage are a recurring mistake by native speakers or something of that nature.

I'd say Microsoft have a way of bending the rules and I know that McLaren have won the championship. While this sounds strange, I believe it is correct English (sorry, I'm not native).   But when it's a small company, would you still use it this way? Is a company always plural, or are small companies singular? I.e., would you say Bakery Johnson makes fine bread or Bakery Johnson make fine bread? Is it My book seller, Woody's, have moved or is it has moved?


I know that $2017 = 9^2+44^2$, but how can I prove that this is the only possible way you can write 2017 as a sum of 2 squares?

Write the prime $2017$ as the sum of two squares  $2017$ can be written as the sum of two squares because it is a prime of the form $p\equiv 1\ ($mod $4)$  Using an appropriate algorithm find the two numbers that, when squared, add to the total of $2017$


Onchange function is not working in Jquery.   In my page i need to add select tag when i click the add button.  My code is here   Using Below code to add a new select tag. This code is working fine.   var counter =1;     var newrow = $(document.createElement('tr')).attr("id", 'newgroup' + counter);   var httttm = "";     httttm += "<select name='input_field[]' class='form-control' ><option value=''>Select</option><option value='input'>Text</option><option value='option'>Option</option></select>		";         newrow.after().html(httttm); newrow.appendTo("#newgroup"); counter++;   Following code is used to get the option value from the select tag. Normally below code is working fine. But when i add the new select tag using above code onchange function is not working.   $('select').change(function (){     var selvalue = $(this).val();                if(selvalue == "option")    {                alert("hai");     }  });

I have a bit of code where I am looping through all the select boxes on a page and binding a .hover event to them to do a bit of twiddling with their width on mouse on/off.  This happens on page ready and works just fine.  The problem I have is that any select boxes I add via Ajax or DOM after the initial loop won't have the event bound.  I have found this plugin (), but before I add another 5k to my pages with a plugin, I want to see if anyone knows a way to do this, either with jQuery directly or by another option.


When you open the door of your spaceship, the oxygen disappears from the ship. So if I put a very very long tube from the Earth to space, would all the oxygen from the Earth automatically aspire into space? And then no one can breathe anymore so everyone dies.

People said outside earth is a vacuum.  But the air does not get sucked from the  Earth's surface. Some said it is due to gravity and some said the speed of air molecules are not high enough to escape.  We know vacuum will suck air like your vacuum cleaner and it has nothing to do with gravity. If outer space is really a vacuum, what prevents air escape the earth?


looks very much as not-an-answer to me but was declined (no evidence). On the bright side: it was at least deleted :-)  Screenshot so <10K can judge as well:        Any idea as to why my flag was declined?

I flagged a post and (choose one)   my flag was marked as helpful, yet nothing was done my flag was marked as declined, yet the post was deleted/edited/closed   Why?


I have a field on my opportunity which is a date. when I add it to my email template, it renders as date time. obviously, i want just the date to render.  Help?  <messaging:emailTemplate subject="This is my subject" recipientType="User" relatedToType="Opportunity">     <messaging:htmlEmailBody >         close Date: {!relatedTo.closeDate}

     </messaging:htmlEmailBody>     <messaging:plainTextEmailBody >         close Date: {!relatedTo.closeDate}     </messaging:plainTextEmailBody > </messaging:emailTemplate>    Output   close Date: Thu Aug 22 00:00:00 GMT 2013   close Date: Thu Aug 22 00:00:00 GMT 2013

I need this date format in a visualforce page: "December 14, 2013". I can't seem to find the format options for visualforce. I read that it's the same as the java messageformat class options, but I cannot find a list for that either.  A little help would be much appreciated


$$\begin{vmatrix} 0 & 1  & 1  &  & 1\\ 1  & a_1 &   &  & \\ 1  &   & a_2 &  & \\ \vdots &  &  & \ddots & \\ 1  &  &  & & a_n \end{vmatrix}$$ If I suppose $a_1,\dots ,a_n\ne0$, I know how to do it, multiply the $i$-th column by $-1/a_i$ and add to the first column. Doing that I get the correct solution $ -a_1a_2 ...a_n(1/a_1+...+1/a_n)$.  How to avoid the zero case ?

I have the following $N \times N$ matrix. \begin{vmatrix} 0 & 1 & 1 & \ldots & 1 \\  1 & a_1 & 0 & \ldots & 0 \\  1 & 0 & a_2 & \ldots & 0 \\  \vdots & \vdots& &\ddots& \vdots\\ 1 & 0 & 0 & \ldots & a_n \\  \end{vmatrix}  There seems to be a pattern going on for  of this matrix, but I'm not sure how I would find the determinant for the $N \times N$ one.


I have created some useful tools and I am willing to put all those tools on a website and let people use those tools and donate me money if they like it. These tools are related to web design and project management etc. But I don't have a budget for advertisement.  Now if I ask a dummy question on Stack Overflow (which I know only my tool can solve or my tool would be the choice) then will this be spam advertisement? Because this way I will reach the exact audience that I need and it will help them? I have not done this yet btw.  Please guide me as i am struggling with this scenario, and also tell me if there is anything wrong with the question and i will update it or change the tags etc. dont downvote. Thank you.

Within the Stack Exchange ecosystem, is there a place for indie developers to post links to their software? Promote, test, discuss, and brag about it? If no, then why not?


Given $f(z) = \frac{1}{1+z^2}$, I want to find the Taylor series of $f(z)$ about $z_0 = 0$.  Intuitively, and based on the formation of a standard power series I have $f(z) = \sum (-1)^n(z^2)^n$.  What I need now is to find the power series for $(\frac{1}{1+z^2})^2$ and $(\frac{1}{1+z^2})^3$.  I assume I'll need to use partial fractions here but I'm a little stuck at the start. Tips would be appreciated.

So the way I think I should approach this is by getting a result for $n=1,2,3...$  and then examine them. I could easily get the Taylor series expansion for $n=1$, but then I don't really know how to proceed, because I can't always break down a power of a polynomial. And a power of a summation doesn't seem as a legit answer either.   Can anyone help? Thanks


would you help me out with examining this sentence? "That might even could happen"  be considered incorrect? Thank you.

I have a friend from the southern U.S. who uses the phrase “might could” quite often. He’ll say, for example:     I might could do that this weekend.    When I first heard him say this, it made me do a double-take. I wasn’t sure whether it’s incorrect, or correct but just not idiomatic outside the southern U.S.


I have favourited lots of question and every time I want to view some question I need to search for that question, which is really annoying. It's difficult to remember the keywords and the exact question I am looking for.  I want to suggest adding a feature which allows you to search any question from your list of favourited questions from a textbox (much like google autocomplete) or have some folder like structure to manage it.  I work on Javascript, jQuery, MySQL, PHP and lately Python and it is difficult to manage these questions.  Update: I still feel that this feature could still improve,rather than having a different page for it,it would be very convinient for evry single user to just click the favourites menu tab and have an autocomplete feature to the search bar.much like google.

I don't know about anyone else, but I have a reasonable list of favourites now, and it can be rather difficult to find the relevant ones at any given time. Sometimes, I have a specific one in mind, others I just want to see all favourites relating to a specific topic. It would be nice if there were a way to organise my favourites by tag, or OP, or possibly just search them.  How can we improve the favourites feature?  Please post your ideas on how we might improve the favourites feature of the Stack Exchange sites. Try to keep each answer to one idea so that the votes reflect the popularity of a single idea.


I have for many year wondered what is missing when I read sentences like     David Canton, the Education Department spokesman, stated:    “(It) shouldn’t have happened. (C)ommon sense should prevail.”    I can understand that (It) might mean mean that the transcriber did not hear the "It" - perhaps the person omitted the word, but "(C)ommon"?   Would that mean that the recording might have some noise drowning the "C" out and the transcriber could not hear it or how do you interpret this?

I sometimes see square brackets used while quoting.  My assumption is that they are replacing a pronoun with what the object of the pronoun, but I never know for sure because I don't usually get to see what the original quote looks like before the modification.  What are these called and what are the rules of use?


I am using TP Link router and local internet provider GTPL. I have server on which I am hosting my website but not able to access it using public ip. I am able to access in same lan with local ip like http://10.167.53.249:8080/ http://192.168.0.106:8080/ **But not with below** http://103.250.136.166:8080/  Please see my router configurations in following screen shot.

I'm running a Samba server on my MacBook and I've also set up port forwarding to said server from my router.  My public IP is 106.51.x.x (according to google and a few other services) and my Mac's local IP is 192.168.x.x, but when I head to my router's configuration page, it says my external IP is 10.242.x.x.  This is what I don't understand, when connected to my home WiFi, using the 10.242.x.x address works just fine. But if I try to access the same over 4G, the connection times out.  As for the public address, neither WiFi nor 4G works.  Is there some setting on my Mac (I'm running MacOS Sierra) that I must alter to make it visible to the public?


In $\triangle ABC$, $X$ and $Y$ are points on the sides $AC$ and $BC$ respectively. If $Z$ is on the segment $XY$ such that $\frac{AX}{XC}=\frac{CY}{YB}=\frac{XZ}{ZY}$, prove that the area of $\triangle ABC$ is given by: $$ \text{area of }\triangle ABC=\left((\text{area of }\triangle AXZ)^{1/3} +(\text{area of }\triangle BYZ)^{1/3}\right)^3 $$

In triangle $ABC$ , $X$ and $Y$ are points on sides $AC$ and $BC$ respectively . If $Z$ is on the segment $XY$ such that $\frac{AX}{XC} = \frac{CY}{YB} = \frac{XZ}{ZY}$ , then how to prove that the area of  triangle $ABC$ is given by $[ABC]=([AXZ]  ^{1/3}  + [BYZ]^{1/3})^3.$


Heres the images of her:     She just laid a large yellow fuzzy sack of babies recently (Were pretty sure were just going to deposit her and her eggs in a grove in the forest soon)  We have lots of brown recluses here in North Carolina, but no idea what she is.  Climate: Humid, Tropical.  Zone: Sneads Ferry, North Carolina, United States.  Size: About 1.5 Inch, leg spans are about 1 inch on their own.

I noticed a really huge, beautiful web on my porch last week, and tonight, I discovered its resident. I'm thinking it's an Araneus diadematus (Cross Orbweaver), but I was hoping for some confirmation.   Can anyone confirm this or offer a better suggestion?


Let $A = (a_{ij})_{n\times n}$ such that $AB = BA$ for every square matrix $B$ of order $n$.  (i) Prove that $A$ is a diagonal matrix.  (ii) Prove that $A$ is a scalar matrix.   How to solve it? I actually started by letting $B$ also be $B_i$ where the $(i, i)$ entry is $1$ and $0$ elsewhere. How do I continue?

Let A = $(a_{ij})_{n\times n}$ such that $AB = BA$ for every square matrix $B$ of order $n$.  $(I)$ Prove that $A$ is a diagonal matrix.  [Hint: Let $B_i$ denote the matrix whose $(i,i)$ entry is $1$, and $0$ elsewhere. Show that $a_{ij} = 0$ whenever $i ≠ j$.]  $(II)$ Prove that $A$ is a scalar matrix.  [Hint: For $i ≠ j$, let $B_{ij}$ denote the matrix whose $(i,j)$-entry is $1$ and $0$ elsewhere.Show that, $a_{ii} = a_{jj}$ for all $i ≠ j$.]  Can someone help me with this question using basic linear algebra concepts? Thanks.


I'm currently a 12th grader and will be studying computer science next year in a college.  I'm attending to a calculus class in my school, but the teacher is teaching very slowly, and I doubt that I will be able to learn anything but limits.  So I decided to learn calculus myself as a preparation for next year; I don't want to fall behind everyone.  What would be a good calculus book for me, a 12th grader preparing for college?

Well I have not started calculus yet but I am really keen to. I would love if you suggest some books.  Points to be noted:   I really don't like the way textbooks are written so please no "textbooks"  I am COMPLETELY beginner in calculus. I know a little bit of trigonometry and what functions are but not really in depth.The book should start from the base, I mean really from the base. I may require a precalculus book too if the books don't cover that. I would really love if the book shows how calculus was developed, why it was developed and things like that.   Well,thanks in advance!


I want to uninstall Chrome OS and install Ubuntu instead. How would I do this?

I have installed Ubuntu 13.04 on my desktop (runs like a charm). Then I used Crouton to install Ubuntu 12. 04 on my chromebook samsung (ARM). It also works quite well.  Here comes my question. Can we have a true Ubuntu (preferably 13.04) on my ARM chromebook?  It seems that the Crouton/Ubuntu is not 100% the real thing.  The best option would be to have the full Ubuntu 13.04 and remove the Chrome OS.


Now that upgrades from 14.04 LTS are enabled, the upgrade still fails for the following repos:  W:Failed to fetch http://172.22.152.125/ubuntu/dists/xenial/main/source/Sources  404  Not Found W:Failed to fetch http://172.22.152.125/ubuntu/dists/xenial/restricted/source/Sources  404  Not Found ... E:Some index files failed to download. They have been ignored, or old ones used instead.   Are there other locations we can use? Or will the script get updated?

How do I select which server Ubuntu will get it's software and updates from? I know how to find the  on the web, but not how to use them.


I am flying from Germany to India with Qatar Airways, in economy class. My total baggage should not exceed more than 30 kgs.  My question is, can I break down this 30 kgs allowance into two bags, as long as the total weight doesn't exceed more than 30 kgs?  I checked the website, there's no information given about the number of pieces that can be checked in - it only mentions the total weight up to 30 kgs.

I'm flying to Europe with Qatar Airways. Baggage allowance shows as 30 kg but I was wondering if I can take two small bags that weigh all together 30 kg instead of a single bag.  It might look like a stupid question but their website doesn't really explain it but I saw someone post somewhere that they checked in 3 bags and it was fine because all together they weighed 30 kg.


As a beginner just wanted an app to check if two numbers are equal in java using Android studio. app crashes when run.pls let help spot the problem. here are the UI and the back end. logcat:NullPointerException: Attempt to invoke virtual method  emphasized text public class MainActivity extends AppCompatActivity {     EditText ednum1,ednum2;     Button btn1;     TextView tv1;     @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);          final EditText  firstnumber = (EditText) findViewById(R.id.ednum1);         final EditText secondnumber = (EditText) findViewById(R.id.ednum2);         final TextView result = (TextView) findViewById(R.id.tv1);        final Button checknumbers  = (Button) findViewById(R.id.btn1);         btn1.setOnClickListener(new View.OnClickListener() {             @Override             public void onClick(View v) {                 double ednum1 = Double.parseDouble(firstnumber.getText().toString());                 double ednum2 = Double.parseDouble(secondnumber.getText().toString());                  if (firstnumber == secondnumber) {                     result.setText("numbers equal");                 } else {                     result.setText("numbers are not equal");                 }              };          });     } }

What are Null Pointer Exceptions (java.lang.NullPointerException) and what causes them?  What methods/tools can be used to determine the cause so that you stop the exception from causing the program to terminate prematurely?


I'm confused, is "have got" a verb? Because when I've searched it in a dictionary, it said "have got" was an equivalent of "have", the form is like the "Present Perfect Tense", and it is the equivalent of "have" in British English. I've ever heard that "have got" can't be used in every situation, and only "have" can be used in all situation and all verbs, is that right?  These are the examples. So, do you hear them in standard British English?  I have already got to go (or) I already have to go.  I never have a new pen when I need one (or) I have never got a new pen when I need one.  I have got to do it (or) I have to do it.  I have still got to research itsign those contracts (or) I still have to research itsign those contracts.  I have just/only got five pence (or) I just/only have five pence.  I have also got to do my homework (or) I also have to do my homework.  I haven't just/only  got 5 pence (or) I just/only don't have 5 pence.  Have/ haven't I just/only got 5 pence? (Or) do/don't I have 5 pence?  I have/haven't also got to do it (or) I also don't have to do it.  Have/haven't I also got to do it? (Or) do/don't I also have to do it?  So In the past, do you use "had got" or "had in BrE? e.g.  I had got 5 pounds (or) I (did have) had 5 pounds.  I hadn't got 5 pounds (or) I did not have 5 pounds.  Had/hadn't I got 5 pounds? (Or) did/didn't I have 5 pounds?

I am really confused now, so I've found out that:  Facts :  HAVE GOT is only used in the present and past form.  the plain "have" is used in all tenses.  HAVE GOT cannot be combined with the modal verbs such as :must, may, might, can, etc. and can't be combined with to+infinitive.  Only the plain "have" can be combined with the modal verbs & it can be combined with to+infinitive. ex. I want to have a pair of shoes (or) I want to have got a pair of shoes.  HAVE GOT and the plain "have" are used in BrE. (Do BrE natives use both ? Could you explain the differences between them?)  The pattern  A. HAVE GOT : I have got.. & I haven't got..& have I got (in the negative, haven't I got ___ ?)  B. HAVE : I do have.. / I have.. & I don't have.. & do I have? (negative, don't I have?)  C. past : I had got /(I did have) I had & I hadn't got /I didn't have & had I got (hadn't I got?), did I have? ( didn't I have?)  Are these facts correct? I await your explanations, thanks.


ret_idx might be null for a new user since its entry in database is not made. So whenever the app detects ret_idx is null, it shows the java.lang.NullPointerException. How do I avoid this exception from crashing my app, considering ret_idx might go null in several cases.  String ret_idx=dataSnapshot.child("name").getValue().toString();


I tried different approaches.   Installing the APKs: Login, Framework, Service and last but not at least Playstore wont work. (I tried it successfully on fire tablet)  In factory mode the menu Point: install from Sd Card wont be Displayed. To install Gapps from there.  Is there any other method to make Google Play Services run on the device?   the navigation tablet is  based on Android 6.0.1  i tried to follow the describtion from @izzy, but if I use the adb sideload i get:      "adb : sideload connection: closed .. trying pre kitkat sideload   method..'   and than the connection fails again and is closed too.   starting the device in factory mode and try to install it says:      "failed to open driver control no such file"   underwards it says that i could use adb sideload, but when i try my computer says      "no connected device"

I have recently installed a custom ROM and cannot find the Play Store. It seems like all apps that belong to Google are missing.  How can I install the Google Apps Package (Play Store, ...) on my Android device?


I'm reading through some of Werkzeug's source and stumbled upon this nugget in the werkzeug.wrappers module.  def _run_wsgi_app(*args):     """This function replaces itself to ensure that the test module is not     imported unless required.  DO NOT USE!     """     global _run_wsgi_app     from werkzeug.test import run_wsgi_app as _run_wsgi_app     return _run_wsgi_app(*args)   What are the fine prints of doing something like this? What's the difference between this definition and another without the global _run_wsgi_app statement?

How can I create or use a global variable in a function?  If I create a global variable in one function, how can I use that global variable in another function? Do I need to store the global variable in a local variable of the function which needs its access?


Use Mathematical Induction to show that for any set $S$, If  $\vert S\vert = n$, then $\vert\mathcal P(S)\vert= 2^n$. How would I approach this question? What would the base case be when I apply it to the left hand side?

Theorem. Let $X$ denote an arbitrary set such that $|X|=n$. Then $|\mathcal P(X)|=2^n$.      Proof. The proof is by induction on the numbers of elements of $X$.      For the base case, suppose $|X|=0$. Clearly, $X=\emptyset$. But the empty set is the only subset of itself, so $|\mathcal P(X)|=1=2^0$.      Now the induction step. Suppose $|X|=n$; by the induction hypotesis, we know that $|\mathcal P(X)|=2^n$. Let $Y$ be a set with $n+1$ elements, namely $Y=X\cup\{a\}$. There are two kinds of subsets of $Y$: those that include $a$ and those that don't. The first are exactly the subsets of $X$, and there are $2^n$ of them. The latter are sets of the form $Z\cup\{a\}$, where $Z\in\mathcal P(X)$; since there are $2^n$ possible choices for $Z$, there must be exactly $2^n$ subsets of $Y$ of which $a$ is an element. Therefore $|\mathcal P(Y)|=2^n+2^n=2^{n+1}$. $\square$      From the above explanation, I don't understand why the set that contains $\{a\}$ will contain $2^{|n|}$ elements when it should clearly be $2^{|1|}$.  The construction of a new set $S$ is the union of the old set with cardinality $n$ and an new element $\{a\}$, therefore the set that do not contain $\{a\}$ still has cardinality $n$ and the set that contains $\{a\}$ is just $\{a\}$, one element...  Can someone please elucidate?


I've seen a lot of these questions, but in my search I haven't managed to find an answer to my problem. I am building a directory system for simple use, where I have divided the first folder into "Parts" and "Results". In the Parts directory, I have folders called "Tex", "Img" and "Combo".   Tex contains four different tex files, chapters. Img contains all images from every chapter. I want all images in one location because some of them appear more than once. If I need to replace one of the images I want it to do so everywhere where it appears. Combo contains the tex file which combines the four chapters into one big book, of sorts. I use the package standalone to rid the chapters from their preamble and to make it a main file. I then use \include with a relative path to the different chapter-files that I want to include.  Going back to the root folder of this directory-system, the other folder is called "Results". This is where I want all of the rendered content (html and pdf). The reason why I am building the system this way is because I am not the end user of the files, which means it should be simple to navigate and understand.  The problem I have appears when I want to use pdflatex to compile the main file. A lot of what I understand is called "nesting" is happening here. I'm rendering the results in the "Results"-folder, which fetches information from the texin the "Combo"-folders which in turn retrieves files from the "Tex"-folder. All of these chapters then wants images from the "Img"-folder.   I get these errors in the terminal when trying the pdflatex command while working in the "Results"-directory:  ! LaTeX Error: File `../tex/Chapter1.tex' not found.  Type X to quit or <RETURN> to proceed, or enter new name. (Default extension: tex)  Enter file name:    If I enter the absolute path to the Chapter1-file  Enter file name: /Users/Rikardny/Documents/temp/Assets/tex/Chapter1.tex    I instead get the error  ! Package pdftex.def Error: File `login.jpg' not found.  See the pdftex.def package documentation for explanation. Type  H <return>  for immediate help.  ...                                                l.48 ...degraphics[width=0.8\textwidth]{login.jpg}  ?    I understand this is a problem because of the relative paths to other files in each of the documents. Whilst in the "Results"-directory, the relative paths point to a different place than in the "Combo"-directory. However I would like to use relative paths because the folders are going to move to different machines later. Is there a way to maintain the directory-system but not change all the relative paths to absolute paths?

I'm working on a mathematics magazine that involves multiple articles from different authors. I would like to give each article a sub-directory in which I can store all the relevant files - .tex, image files, etc. However, when I then \include the article .tex file from the master file, the images won't be linked correctly without editing.  For example, suppose the article is stored in articles/article1/ and includes an image matrix.png. In the article .tex file this would be inserted, normally, through \includegraphics{matrix.png}. However, when we move to including the article in the magazine through the master file, all these instances would have to be changed to \includegraphics{articles/article1/matrix.png}  So, is it possible to change the LaTeX working directory before including the article such that instances of \includegraphics will not have to be changed, but rather that LaTeX will know to search for these files in the article directory? I'm thinking that this would be similar-ish in functionality to HTML's base href command for links.  Or, is there a better way to achieve all this?


I'm wondering about the perennial problem that arises when presenting multiple options, where the user can select none, one, or several options.   Using checkboxes, it's not clear whether a user    intentionally selected none of the options or just ignored the question.   Like so:         – Wireframes created with  See. I don't know whether you don't like any fruit, or whether you just don't want to tell me.   So if I need to know whether the user answered the question, then it makes sense to include a "none of the above" option at the end of the checkbox list.  However, there's .  With a small number of options, ....          ...but with a larger number of options, radio buttons quickly become untenable:          So I was quite excited today to stumble across what might be a solution to the problem—a hybrid checkbox/radio control:          When the radio button is selected, the checkboxes become deselected, and when the checkboxes are selected, the radio becomes deselected.  At first glance, this looks like a great solution...but before I start adopting it, I want to check if it may confuse people. Perhaps they view the separate shapes as corresponding with separate questions; or perhaps they don't understand why clicking on some things (but not just any thing) may cause others to become deselected; or perhaps they don't distinguish between checkboxes and radio buttons at all and they're slowed down by wondering why one of the buttons is a different shape from the others.  Has user testing found that this control is commonly understood?  Are there particular demographics or psychographics that find this hybrid control problematic?

I am working on a series of complex life insurance forms and trying to optimize using standard conventions...  I have this nasty list of medical diseases and a mutually exclusive option, "None of the above".  In the case where the user does not have any conditions, the client requires users to explicitly state this for legal reasons.  Any advice?


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

I wonder if there is something like a standalone Version of Visual Studios "Immediate Window"? Sometimes I just want to test some simple stuff, like "DateTime.Parse("blah")" to see if that works. But everytime i have to create a new console application, put in my code and test it.  The Immediate Window sadly only works when I am debugging something. Could PowerShell do that? Just open a CLI similar to what cmd.exe does, allowing me to execute some C# code?


I need to include some inline code in a text with a background color. I use \lstinline for including code in a text and \colorbox for making a background color for it.   \lstinline!$! produces s (without gray background) and \colorbox{Gainsboro!60!Lavender}{\lstinline!$!} produces s. \lstinline!\(! produces \( (without gray background). This is everything as I need.  But there is a problem:  When I use \colorbox{Gainsboro!60!Lavender}{\lstinline!\(!} it produces only ( instead of \(. I found the solution and use \colorbox{Gainsboro!60!Lavender}{\lstinline!\\(!} to produce \(. So, there is a need to use an escape character.    Question:  Is there a way to include some inline code with background color (I need to use at least svgnames or some with more collors) in a text without to worry about the need to use escape characters in inline code?    Complite code:  \documentclass{article}  \usepackage[svgnames]{xcolor} \usepackage{listings}  \begin{document}  \lstinline!$!  \colorbox{Gainsboro!60!Lavender}{\lstinline!$!}  \lstinline!\(!  \colorbox{Gainsboro!60!Lavender}{\lstinline!\(!}  \colorbox{Gainsboro!60!Lavender}{\lstinline!\\(!}  \end{document}

Update:  In addition to my previous post, here's a screenshot to give you a better visual example. This was created with HTML and CSS for demo only.  In CSS, the code part is made using font-family: monospace, sans-serif;, background: #EFF0F1;, display: inline-block;, and padding: 2px 5px;.  I wonder if there's a simple way to mimic this style in LaTeX using \lstinline (or better options) without \Colorbox (if possible). All instances of \lstinline would have the same style.  What I mean by simple is that I thought I could just write something (once) inside \lstset{} in the preamble--which is simple--rather than typing \Colorbox in every instances of \lstinline--which is long and awful for a novice like me. Otherwise, using \Colorbox would be just fine.    Original question:  I need to create inline codes with gray background using either \verb or \lstinline. I've read  which use \Colorbox which works great!  My question: Could we achieve the same effect just using \lstinline alone, without \Colorbox so it would be more simple?  \documentclass{article} \usepackage{xcolor} \usepackage{listings} \definecolor{mygray}{rgb}{0.8,0.8,0.8} \lstset{% basicstyle=\ttfamily, breaklines = true, backgroundcolor=\color{mygray}, } \usepackage{realboxes} \begin{document}  % demo using \lstinline only This is \lstinline|my code|  % demo using \lstinline and \Colorbox This is \Colorbox{mygray}{\lstinline|my code|}  \end{document}


Let $r=\sqrt{6+4\sqrt{2}}-\sqrt{2}$, then $r+\sqrt{2}=\sqrt{6+4\sqrt{2}}$. Squaring both sides, we get $$r^2+2r\sqrt{2}+2=6+4\sqrt{2}$$ which is the same as $r^2-4=2\sqrt{2}$. Squaring both sides again, we get $r^4-8r^2+16=8$ or $$r^4-8r^2+8=0.\tag{$\star$}$$   The rational zeros theorem tells us that the only possible rational solutions to ($\star$) are $±1$, $±2$, $±4$, $±8$. I do not know where to go from here. Please help me complete this proof.

What I've done so far:   Let $$r = \sqrt{4+2\sqrt{3}}-\sqrt{3}.$$  Thus, $$r^2 = 2\sqrt{3}-2\sqrt{3}\sqrt{4+2\sqrt{3}}+7$$  and $$r^4=52\sqrt{3}-28\sqrt{3}\sqrt{4+2\sqrt{3}}-24\sqrt{4+2\sqrt{3}}+109.$$  I did this because in a similar example in class, we related $r^2$ and $r^4$ to find a polynomial such that $mr^4+nr^2 = 0$ for some integers $m,n$. However, I cannot find such relation here. Am I doing this right or is there another approach to these type of problems.


I am trying to install cuda-9 on ubuntu 18.04 but cuda-9 does not support gcc later than 6. If I do "sudo apt install gcc-6" or any lower version it says, unable to locate gcc-6.  Can somebody help me with this.

Is there any tutorial to install CUDA on Ubuntu 18.04?  The instructions on the Nvidia website for 17.04 and 16.04 do not work for 18.04.  I get a message telling me to reboot then re-run the installer.  However when I do this I get that same message again.


Show that the polynomial $(x-1)(x-2)...(x-n)-1$ is irreducible over $\mathbb{Z}$. [hint: if the polynomial factors consider the values of the factors at $x = 1,2,3....,n$.  Show that the polynomial $(x-1)(x-2)...(x-n)+1$ is irreducible over $\mathbb{Z}$ $\forall n \geq 1, n \neq 4$.  I've been running around in circles on this one for awhile now and can't seem to get anywhere! Some insights would be greatly appreciated! Thanks yall!

I try to solve this problem. I seems to come close to the end but I can't get the conclusion. Can someone help me complete my proof. Thanks          Show that the polynomial $h(x) = (x-1)(x-2)\cdots(x-n) + 1$ is irreducible over $\mathbb Z$ for all $n\ge1$ and $ n\ne4$.      Suppose $h(x) = f(x) g(x)$, then we must have $f(i)g(i) = 1$ for all $i = 1,2,...n$. So both $f(i)$ and $g(i)$ are $1$ or $-1$. In either case, $m(x) = f(x) - g(x)$ has degree smaller than $n$ and have $n$ different roots ($1,2,...,n$). So we must have $m(x) = 0$. Then $h(x) = f(x)^{2}$. So $n$ must be even. Let $n = 2k$. Because $f(x)$ has degree $k$, there are $k$ values from $\{1,2,...,2k\}$ at which $f(x)$ is $1$ and $k$ values at which $f(x)$ is $-1$.  This is where I got stuck. Hope some one can help me solve this. Thanks.


Is it possible that some condition is not necessary but yet sufficient?  As far as I know a sufficiency entails necessity. If something is not necessary then it can not be sufficient. Is that right?

What is the logical difference between something being necessary in order for something else to be true; as opposed to something being sufficient to make something else true.  i.e.  Fuel is sufficient to make an internal combustion engine run.  vs  Fuel is necessary to make an internal combustion engine run.  and what are some subtle examples of how the difference between these two things can greatly impact the meaning of a sentence, discussion, or conclusion.


I am trying to join a .csv file with a .shp file in QGIS but QGIS is unable to read the data in my .csv file as it indicated that the variables are string of length and precision 0. As a result, I am unable to use the method of create a new column of numeric characters and the option to add a new column or to use the field calculator is disable in my attribute table.

I read in a CSV file for linking to a .shp file.   All the variables that are just numbers came in as text.   How do I change the text variables to numeric in QGIS?


I am trying to get an iso to make a bootable usb on my linux machine. However when I try to download 17.10 it gives me a text file and not a disc image. I have tried to re download multiple times and it keeps doing the same thing over and over again.

I'm having problems trying to download the iso for Ubuntu 17.10 from the official website. It shows a "file incomplete" message right after I click the download button:    Although my browser is Chrome, the same behaviour happens with Firefox as well.


I want to call functions from a C++ library in a python code, and I don't how it should be done. I am wondering whether it is possible to use numpy.array as input for C++ pointers or whether I need to modify them to transfer from python to C?

What would be the quickest way to construct a Python binding to a C or C++ library?  (I am using Windows if this matters.)


Is there a way to access the Night Light setting in Ubuntu Studio? I could access in the GNOME install but can't fund it in STUDIO.

I recently had an eye appointment, and the optometry student who saw me told me that, for my next pair of glasses, I should get lenses with "blue blocker" material.  There is some (scant) evidence that blue light from computer monitors causes macular degeneration over time.  Prescription lenses with blue blocker look ugly, IMO, so I opted not to get the blue blocker in my lenses.  At the same time, I don't want to lose my eyesight if I can avoid it.  Are there software solutions available in Ubuntu for turning off or substantially reducing blue light emitted from my monitor -- at the particular wavelengths that have been shown to harm eyes?


On a site called Codingbat.com I have been presented with the challenge of detecting whether a string ends in "ly" or not. I have thoroughly checked my code, but it doesn't seem to be working. When I input "ly" it detects perfectly fine, however, words such as "oddly" or "exactly" don't issue the true Boolean response as they should. Here is my code so far:  if (str.length() > 1) {   String lastTwo = str.substring(str.length()-2, str.length());   if (lastTwo == "ly") {     return true;   } else {     return false;   } } else {   return false; }

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?