How do I prove that a function $f$ is injective knowing that $ f : \Bbb{N} \rightarrow \Bbb{Q}$ is defined such that 1.) $f(2n) = \frac{1}{f(n)+1}$ and 2.) $f(2n + 1 ) = f(n)+1$ for all $n\in\Bbb{N}?$ I forgot to mention that $f(0)=0$

Let $f:\mathbb{N} \to \mathbb{Q}^+$ defined as follows : $$\begin{cases} f(0) = 0 \\ f(2n) = \dfrac{1}{f(n)+1} \\ f(2n+1) = f(n)+1 \end{cases}\,.$$ It is asked to prove the injectivity then the surjectivity of $f$.  After examining first values taken by $f$, I proved by induction that $f(2^k)=\dfrac{F_k}{F_{k+1}}$ where $(F_n)$ is the fibonacci sequence. Also one notes that if $m$ and $n$ have different parity then we can't have $f(m) = f(n)$ since $f(2\mathbb{N}) \subset (0,1)$ and $f(2\mathbb{N}+1) \subset [1,+\infty)$. Any ideas on how to finish the proof of injectivity and any thoughts about surjectivity are welcome. Thanks


Question is simple, i subscribe to a 200GB icloud drive. My desktop has 60GB available for storage (on SSD)  Will i be able to fill my icloud drive with data from my dying USB external drive, and can you explain me how to do that ? (i just put 20GB from my external drive to C:\mysuser\icloudrive\stuffs\ and now i only have 40GB available on my windows 7 C:\ ), 180Go remain to be transfert, how can i do that ?

I am using OS X 10.10 with iCloud Drive. I am thinking of upgrading to a bigger storage plan (at the moment: 5GB).   I am running this Version on a MacBook Air with 128GB.      If I buy the 500GB package, does it mean that I fill up my local hard   drive automatically when I upload things to the iCloud Drive?   iTunes has the Option of stream the music i didn't download yet.   How does iCloud Drive behave? Is there any Online Document?


When I go on my profile, I've got different reputation badge than on the application.  For example , on the site, for the iOS tag, I've got 59, but on the iOS app, I've got 72  Website profile :    Mobile profile :

I checked yesterday and today the new homepage in the Android app. Very surprised I saw that I would almost reach a silver tag badge, that confused be because I always take a look on possible badges I can get. However I compared the score with the website and I got a total different results. See this two screenshots:


How would I go about solving this question?  Use induction to prove that for all integers $n ≥ 1$, $$1^2 + 2^2 + 3^2 + \dots + n^2 = \frac{n(n+1)(2n+1)}{6}$$

I encountered the following induction proof on a practice exam for calculus:  $$\sum_{k=1}^nk^2 = \frac{n(n+1)(2n+1)}{6}$$  I have to prove this statement with induction.  Can anyone please help me with this proof?


I want to prove this statement:  $$(A_1 \cup A_2)^c  =  {A_1}^c \cap {A_2}^c$$  What I have realized so far, is that  $$(A_1 \cup A_2)^c \implies x \not\in A_1 \textrm{ and } x \not\in A_2 \implies x \not\in (A_1^c \cap A_2^c)$$ (Though I'm not sure if my approach is correct since I'm stuck)  but I am not sure how to proceed. Any help would be greatly appreciated.

I want to prove this statement:  $$(A_1 \cup A_2)^c  =  {A_1}^c \cup {A_2}^c$$  where the $c$ means the complement.  Any help would be greatly appreciated.


I have two output chains like this:  chain OUT {     type filter hook output priority 0; policy accept;     ct state established,related accept     oif "lo" counter packets 0 bytes 0 accept     ip protocol icmp counter packets 3 bytes 252 drop     counter packets 0 bytes 0 log drop }  chain ping {     type filter hook output priority -10; policy accept;     ct state established,related accept     ip protocol icmp counter packets 3 bytes 252 accept }   ping chain has lower priority of -10 so packets first traverse through this chain and are accepted. Why those accepted icmp packets are next dropped in OUT chain ? I want temporarily enable and disable rule like in this example. How to achieve this ?    nftables: 0.9.2-2 kernel: 5.3.9-3

I have a Fedora 31 system on which I am using iptables-nft. I need this because there is still a bunch of software that expects the legacy iptables command line tools.  This means that my nftables configuration has the corresponding set of tables to match the legacy configuration:  table ip filter table ip nat table ip6 filter table ip mangle table ip6 nat table ip6 mangle   I use a containerized VPN service that, prior to nftables, would enable masquerading on my primary ethernet interface by running something like this when the vpn comes up:  iptables -t nat -A POSTROUTING -s 172.16.254.0/24 -o eth0 -j MASQUERADE   Since upgrading to Fedora 31 and iptables-nft, this no longer works. The container (running alpine) does not have the iptables-nft compatability wrapper, but it does have the nft command itself.  I can't use the nft cli to add rules to the existing tables, because this will break iptables-nft. But I can create new tables. I was hoping I could just apply a configuration like this:  table ip vpn {     chain postrouting {         type nat hook postrouting priority filter; policy accept;         ip saddr 172.16.254.0/24 oifname "eth0" counter masquerade     }      chain forward {         type filter hook forward priority filter; policy accept;         ip saddr 172.16.254.0/24 counter accept     } }   ...but this doesn't appear to have any impact. By setting the chains in this table to priority 0 I was hoping they would match before the legacy nat table, but that doesn't appear to be the case.  Is there a way to make this work?


I had Windows 7 and Ubuntu 14.04 in dual boot mode on my computer.  I since upgraded Win 7 to Windows 8 and then to Windows 10.  GRUB obviously has disappeared.  I now want GRUB back. But now Windows 10 I guess is EFI mode while the old Linux mint installation used the traditional GRUB in BIOS.   How do I restore GRUB in such a scenario?  Any help is appreciated.  Thanks!!!

I installed Windows 7, which ate Ubuntu's boot file. When starting up the computer, it now goes straight to Windows, without giving me the option of booting Ubuntu.   How can I get Ubuntu back?


so the exercise goes:  Let $E, F$ and $G$ be given sets and let the functions $f: E \to F$ and $g: F \to  G$ be given. Consider the claim:  if $f$ is surjective and $g$ is surjective  $\implies g\circ f$ is surjective.  The claim is either true or false. If it is true, prove it. If it is false, give example of 3 sets of $E,F,G$ and two functions $f,g$ where the fuctions $f:E\to F$ and $g: F\to G$ are surjective but $g\circ f$ isn't surjective.  How should I think about all of this? We've had so few tasks in our course on this subject

Suppose we have two functions, $f:X\rightarrow Y$ and $g:Y\rightarrow Z$. If both of these functions are onto, how can we show that $g\circ f:X\rightarrow Z$ is also onto?


I'm trying to create a method that can exchange the location/reference of two class variables, but I can't change the reference of the class variable that is calling the method (this), so I'm wondering is there any way to get around this.  public void exchange(Card x) {     Card y = this;     this = x;  //this doesn't work     x = y;  }

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


I have data from three different groups (n=67, 28, 25).  Can I use ANOVA to compare them or is the first group size too large relative to the size of the other two groups?  I have seen lots of texts that say the groups need to be of equal size but I have seen some suggestions that if the groups size are within a 1:3 ratio (smallest group size to largest group size) ANOVA can be applied.

I have data for three unequal groups: $N = 44$, $N = 354$ and $N = 347$. Is it possible to compare all three groups running a one-way ANOVA or is the first group too small?


"The toy train is made of plastic."   Or     "The toy train is made from plastic."   Which one is correct? Why?

Which is the correct answer to fill in the gap in "Beer is made ____ yeast, water, hops and malted barley"?   of from with out of   I am leaning toward '2'. "Made from" can be used to describe a manufacturing process.    I originally liked '3', but I don't like it now. I would use '3' if I mentioned secondary ingredients, as in "This beer is made with raw apple cider."


Statement: $[a, b] \cap \mathbb{Q}$ in $\mathbb{Q}$ is not compact. Thus the interior of all compact subsets of $\mathbb{Q}$ is $\emptyset$.   I am trying to understand the first sentence. I read that a closed subspace of a compact space is compact, so for example, consider the unit interval $[0, 1]$ which is a compact space. Take a closed subspace $[0, 1] \cap \mathbb{Q}$ of $[0, 1]$. This set is closed since it just consists of all the rational numbers in between $0$ and $1$, including $0$ and $1$. So it is a closed subspace of a compact space. But why isn't this compact?

Is $[0,1] \cap \Bbb Q$ a compact subset of $\Bbb Q$?  I get the feeling it isn't compact, but I can't figure out a way to prove this.  I understand that,  in $\Bbb Q$, any open set $U = \Bbb Q \cap O_i$ such that $O_i \subseteq R$.  But I can't figure out a way to construct a finite set that doesn't contain the intersection set.


I have an HP box with a 32bit processor and 80gb hard drive that currently has XP pro as the OS. I downloaded Ubuntu to the hard drive  but can't get it to open or boot. I welcome any suggestions.

I would like to see a full how-to guide on how to install Ubuntu.


I have a really strange situation here. My PC works fine, at least in most cases, but there's one thing that I can't deal with. When I try to copy a file from my pendrive, everything is ok -- I got 16-19M/s , it works pretty well. But when I try to copy something to the same pendrive, my PC freezes. The mouse pointer stops moving for a sec or two, then it moves a little bit and it stops again. When something is playing, for example, in Amarok, the sound acts like a machine gun. The speed jumps from 500K/s to 15M/s, average 8M/s. This occurs only when I'm copying something to a pendrive. When the process of copying is done, everything backs to normal.   I tried everything -- other pendrive, a different USB port on front panel or those ports from back, I even changed the USB pins on motherboard (front panel), but no matter where I put my USB stick, it's always the same. I tried different filesystem -- fat32, ext4. I have no problem with the device on Windows, on my laptop. It has to be my PC or something in my system. I have no idea what to look for. I'm using Debian testing with standalone Openbox. My PC is kind of old -- Pentium D 3GHz, 1GiB of RAM, 1,5TB WD Green disk. If you have something that would help me to solve this issue, I'd be glad to hear that.  I don't know what else info I should provide, but if you need something, just ask, I'll update this post as soon as possible.  I tried to reproduce this problem on ubuntu 13.04 live cd. I mounted my encrypted partition + encrypted swap and connected my pendrive to a usb port. Next I tried to start some apps, and now I have ~820MiB in RAM and about 400MiB in SWAP. There's no problem with copying, no freezing at all, everything is as it should be. So, it looks like it's a fault of the system, but where exactly? What would cause such a weird behavior?


Is it determined the same way as "healthy" weight?  Someone told me that for weight, they do it by measuring a large number of people and see who gets sick and who doesn't and correlate that weight.    Then I was in a forum where someone was saying the requirements are different and some can have 6 hours and be okay and some need 9 hours and I been googling for a few hours but can't find out how doctors would determine that, like is there a list of studies where they looked at different ages, men vs women, different personalities, race, etc, and how much sleep they need?  I read in a couple of places that women need more sleep but couldn't find the study that proved that.  One site mentioned Duke university but no link to the study.

The common consensus is that most adults should get 8 hours of sleep a night.  However, sleep needs are highly variable, with some people needing more to function properly, and some gaining little benefit past just a few hours. I'm trying to learn more about the statistics here.  I'd imagine sleep needs would fit a normal distribution, with a median of around 8 hours and a standard deviation of around an hour. The  would then put 68% of adults in the 7-9 hour range, 95% in the 6-10 hour range, and 99.7% in the 5-11 hour range, but that's just a guess.  Has this distribution been studied, and where?


I have flying from France to Qatar tomorrow, I have to go from France to London Airport from Terminal 4 to Terminal5, do I have a teransivisa to enter London Airport?

Is there a website or some other way to find out if I need a transit visa for a short stop in the UK on my way somewhere else? Ideally this should give me the answer for all nationalities, and take into account any other visas I may have.


I'm reading "categories for the working mathematician " of MacLane. At page 202, we define what is a morphism of short exact sequences (in an abelian category) and say that  this form the category of short exact sequences. This category is additive. My question is : is this category abelian? First my intuition was "yes" but then I tried to prove it... Now I'm convinced that the answer is "No" because of some constructions we can not do with kernels.  Any help? Any counterexample?

I'm wondering whether the category whose objects are short exact sequences of abelian groups, and whose morphisms are commutative diagrams of such short exact sequences, is cocomplete. Working naively, it seems you can get coproducts by taking them componentwise. However, for coequalizers, I think we are not so lucky. Consider the two short exact sequences $0 \rightarrow 0 \rightarrow \mathbb{Z} \rightarrow \mathbb{Z} \rightarrow 0$ and $0 \rightarrow \mathbb{Z} \rightarrow \mathbb{Z} \rightarrow 0 \rightarrow 0$ with maps between integers being the identity. Consider the morphism from the first sequence to the second which is the identity on the middle map between the integers and obviously zero elsewhere. Then taking cokernels componentwise would give $0 \rightarrow \mathbb{Z} \rightarrow 0 \rightarrow 0 \rightarrow 0$, which clearly cannot be exact.   So the obvious candidate for cokernels is not the correct one, but perhaps there is another not-so-obvious choice. I'm wondering how I might go about showing whether or not there are coequalizers.


The project(written in Java) is getting large and large and some code will never be used. Is there a way to detect those dead/unuseful code and clean them up. I'm open for ideas.

What tools do you use to find unused/dead code in large java projects? Our product has been in development for some years, and it is getting very hard to manually detect code that is no longer in use. We do however try to delete as much unused code as possible.  Suggestions for general strategies/techniques (other than specific tools) are also appreciated.  Edit: Note that we already use code coverage tools (Clover, IntelliJ), but these are of little help. Dead code still has unit tests, and shows up as covered. I guess an ideal tool would identify clusters of code which have very little other code depending on it, allowing for docues manual inspection.


I've always seen MACs as a way to provide integrity and authentication. You would just append it to some message in clear.  But this is clearly not the case when you're doing Encrypt Then Mac. When you do that you provide authentication to something that already has authentication (to decrypt we need to know the key). So why use a MAC when we can use a hash instead: $E(m | h(m))$? (i.e., encrypt the message appended to a hash of the message)

It seems that even in MAC-then-encrypt systems like SSL, something like HMAC is used rather than a plain hash. Why?   Suppose we use some stream cipher; then why can't we use $Encrypt(m | H(m))$ as the MAC-then-encrypted version of the message? Assuming no bad relations between $Encrypt$ and $H$, what are the possible weaknesses? It seems that in this case we are encrypting the hash with part of a secretly keyed stream cipher keystream, and the hash is secure; does this not fulfil an approximation of the ideal MAC?  This must be somehow bad, since no secure protocol seems to use it. Why?


I have a script that is used to start my application and it works fine. However the issue is that I need to be able to execute that script automatically at boot up in case of a power failure or a reboot.  Could anyone please guide me as to how can I do this?

I would like to run the simple shell command echo 1 > /proc/sys/kernel/sysrq at each boot, to enable the sysrq keys. When in boot should this be done, and where should I put a script to do it?


Using Inclusion-Exclusion, find the number of ways to write a word of length k over an n-letter alphabet so that the word uses every letter at least once?  how should I approach this?

Given an alphabet of size $n$, how many strings of length $c$ contain every single letter of the alphabet at least once?  I first attempted to use a recurrence relation to work it out:  $$ T(c) = \left\{ \begin{array}{cr} 0 &\mbox{ if $c<n$} \\ n! &\mbox{ if $c = n$} \\ T(c-1) \cdot n \cdot c &\mbox{ if $c > n$} \end{array} \right. $$  As there's no strings that contain every letter if c < n, and if c = n then it's just all permutations. When c > n you can take any string of size (c-1) that contains all letters (of which there are $T(c-1)$ to choose from), you choose which letter to add (of which there are $n$ choices) and there are $c$ different positions to put it. However, this gives out results that are larger than $n^c$ (the total number of strings), so it can't be right, and I realised it was because you could count some strings multiple times, as you can make them taking different inserting steps.   Then I thought about being simpler: you choose n positions in the string, put each letter of the alphabet in one of those positions, then let the rest of the string be anything:  $$ {c\choose{n}} \cdot n! \cdot n^{c-n} $$  But again this counts strings multiple times.  I've also considered using multinomial coefficients, but as we don't know how many times each letter appears in the string it seems unlikely they would be much help. I've also tried several other methods, some complicated and some simple, but none of them seem to work.  How would you go about working out a formula for this? I'm sure there's something simple that I'm missing.


My professor and I have been trying to publish a paper, but it keeps being rejected. A journal emailed my professor asking her to submit the paper to them, but I am not sure it is legitimate.   None its papers have DOIs. It is OA, but only one issue is available and it has <5 papers   Are these warning signs?

A colleague and I recently submitted a paper to a journal with an impressive-sounding name, the "International Journal of Artificial Intelligence and Computational Research". According to ,      IJAICR is a referred [sic] journal in the field of computer science, artificial intelligence and soft computing methods.   It was accepted two days after we submitted it. That's too fast. We were suspicious. Although the journal said that all papers are peer-reviewed, we could not see how that was done in two days. Plus, we received no comments from the reviewers. Also, the submission guidelines didn't ask for a "blind" copy (without our names or any references to who we were).   But wait, there's more.  The acceptance letter asked us to send them US$300 to publish it. We did not. We've withdrawn our submission and will submit a new version of the paper to a more reputable journal in the coming months.  How might we make a better choice of respectable journals before we submit next time?


Downloaded the latest copy of Tiny Cad but it throws out an error when I try to enable it. See the image below. I have no clue what is happening. Does anyone have a solution to this?  I am using Blender 2.75. Tiny Cad's version is 1.2.0

I created this siding generator and I have been adding some new features and I have encountered some problems that I just can't seem to get around. Currently it is not installing into Blender 2.72 properly, it works fine from the text editor, but if you try and install it as an  you get an error like this:  Traceback (most recent call last):   File "C:\Program Files\Blender Foundation\Blender\2.72\scripts\modules\addon_utils.py", line 299, in enable     mod = __import__(module_name)   File "C:\Program Files\Blender Foundation\Blender\2.72\scripts\addons\add_mesh_siding\__init__.py", line 12, in <module>     from add_mesh_siding_utils import * ImportError: No module named 'add_mesh_siding_utils'   Even though the other file is right there as well. I don't get what changed, it used to work just fine.


Was the singularity at the big bang a black hole? If not, how does the singularity compare to a black hole?

TV documentaries invariably show the Big Bang as an exploding ball of fire expanding outwards. Did the Big Bang really explode outwards from a point like this? If not, what did happen?


I want to write a gui to an application that is now CLI that needs to "look good" in both KDE and Gnome DE's, taking optimal advantage of a users settings for appearance.  If I select Qt or GTK+ will I be able to do this?   Do they integrate well with both DE's? Or does a KDE user need gnome libs and vice versa to run them?  My development language of choice will be C++

I have a large GUI project that I'd like to port to Linux. What is the most recommended framework to utilize for GUI programming in Linux? Are Frameworks such as KDE / Gnome usable for this objective  Or is better to use something more generic other than X?  I feel like if I chose one of Gnome or KDE, I'm closing the market out for a chunk of the Linux market who have chosen one over the other.  (Yes I know there is overlap)    Is there a better way? Or would I have to create 2 complete GUI apps to have near 100% coverage?  It's not necessary to have a cross-platform solution that will also work on Win32.


I am not interested in Many Worlds Interpretation because I think it’s mental and after some personal research I found out that it wasn’t (despite some claims otherwise) popular among physicists  at all.  But in the orthodox interpretation, what does being in a superposition mean. Does it mean it isn’t in any position yet before it is measured and has several possibilities. Or is it actually in multiple states/places at once. In the talk of Serge Haroche it seems like the latter  also the way David Wineland’s research is being described here www.nobelprize.org/uploads/2018/06/popular-physicsprize2012.pdf seems to say it’s in multible states at once. But I’ve also seen it described (for instance by David Mermin) as being nowhere untill measured. Which one is it?

Is  purely conceptual or does it represent some real "thing"?  Said another way, is superposition thought to have some tangible physical manifestation or is it simply the lack of physical determinism, except as defined by a wave function?  It seems like my question might be semantic.  For example, it is said that   superposition is obeyed, like a law superposition can be observed, like a phenomena superposition describes behavior   I guess my question is, can superposition be measured like an electrical charge, or is it simply the lack of knowable position.


I think I have a refurbish desktop computer since it has no labels or names on it. But the motherboard is a Gigabyte GA-H61M-S2PV.  Now when  I switch on the computer, fan spins, lights on power/reset button comes on, everything looks normal but the screen displays "No Signal". During startup, a long continuous sound comes on after 3 beeps. Does not stop until i switch off.  RAM: 8Gb, Windows 7 Home Premium.  Anything else please let me know so i can provide.

Due to the amount of beep codes a PC can give, there are many questions on Super User about beep codes! I'm hoping this post will help to provide a community answer about all (dare I say all?) beep codes, with my fictional question.  When I try to turn my PC on, I hear some beeps. This is not beeping from the HDD or fan, but from the motherboard. Regardless of the number of beeps, what do the beeps mean?


I followed a tutorial on how to make something look like metal, it worked in the video and seems to have worked for everyone in the comments. For me it looks like this even tho I have checked that everything is the same as in the video. What did I do wrong? Also I'm wondering what the little piece of white is in the eye. Tutorial I used:

When I apply a glossy shader to the material of my text, the text becomes just black. Why?    I have lamp and everything, but the problem persists. The text is red before I add the glossy shader.  I'm using Cycles render.   Thanks!


How to write a virtual host config in apache for, a particular domains is not present in the list we mentioned in the vhost configuration, automatically apache need to redirect to our mentioned website in the config..... For eg:(listed domains) xxx.com yyy.com zzz.com  Suppose someone have to register subdomain or domain with our server ip like aaa.com, after they trying to access the aaa.com, apache automatically redirects to our mentioned site in apache vhost config....

we have an godaddy account for dns, and we registered our servers in godaddy dns admin console, right now we have an problem, our case is our registered server ip in godaddy dns can able to register  any one of other dns service providers, it might be an issue, someone can easily able to register subdomains to our server ip easily.For eg: if some one have to register subdomain in the name of porn sites and those subdoamins it's pointing to our servers directly it would be an issue for us.How to avoid this case.Please can anyone help for this problem.


I remember a book from the 1980s set in the future. The main character was a boy traveling to see a relative (uncle? grandfather?), but you didn't actually have to travel anymore....Instead, his consciousness was transferred into a robot that looked just like him at his relative's place. The only way you could tell the difference between human and robot was this zipper like scar on the back or back of the neck??  I could have sworn this book was mentioned in Reading Rainbow.

This was a 'young-adult' SF novel I read in the late 1970's, about the same time I was reading Voorloper by Andre Norton, Madeleine L'engle's Wrinkle In Time books and the Dragonfall 5 young adult novels. so I am not sure if it is actually one of the Dragonfall 5 stories, but I can't confirm it is or isn't by reading available synposes online.   As I recall, the story went something like this...    * SOME SPOILERS BELOW *  A young person and sibling - I think female protag and younger brother, but not sure - is scheduled to visit their aunt and uncle on another planet but to make the voyage in a timely fashion, must utilize this new consciousness transference technology to transmit their consciousness across the cosmos to a host replica body at the destination. After arriving at the destination the protagonist is impressed by their new body and is aware of the only way to tell they are in a replicant body is a small seam, scar or patch on their back, I think near the top of their spine, just below the collar of whatever clothing they wore.  The mystery begins when the protagonist realizes their hosts also sport the same scar when they should legitimately be in their real bodies.  The plot thickens when the protag or sibling finds a room of people in stasis when their replicant counterparts are roaming the same planet, and is subsequently caught in the act.  Sadly, I do not remember anything else, including the reasoning behind the deception.  I was quite young when I read this novel, so I probably got some of the details mixed up, but would love to know the name and author of the novel if anyone remembers.


I just got lydia as a follower and have been doing some quest with her. I decided to give her my orcish armor so she can tank better for me but now i have a problem. Every time i dismiss her she Unequips her armor and is just naked. I tried taking away the orcish armor to see if see reverts back to her steel armor but it doesn't work she is still walking around nude. I have already try the disable, enable, and rest AI commands but it didn't solve the problem.

So, I was interested in seeing if I could get Iona to wear some more common clothes around the house.  I pretty much just leave her there most of the time anyway, so there's no point in her being always dressed for battle.  I couldn't seem to get her to un-equip her standard armor, and she wouldn't put on regular clothing or lesser armor while it was equipped.  So, after I finished leveling and perking up my pickpocketing, I stole the Steel Armor straight off her back.  After that, I gave her some more suitable house attire (via "Follow me..." -> "I need to trade...") which she gladly put on.  However, when I later left and returned to the house, I found her wandering around in her undergarments!  I checked her inventory, and found the clothes I'd given her were still there and her armor wasn't.  So, she had no good reason not to be dressed in what had been handed to her.  Later, I figured out this continues to happen even if I leave a full set of Legendary-quality Dragonscale Armor with her.  And, later on... I found out this is also the case with Lydia and Jordis.  They'll all wear their clothes immediately after being given them.  But if I leave them at home, I'll return to find them bare.  Is this a known bug?  Is there any way around it without using the PC-only console?


There seems to be a lot of questions on askubuntu and info on the web on how to install Ubuntu and Windows in dual boot, but everywhere Ubuntu is installed afterwards. I would like to install Windows on the system which is already running Ubuntu. It uses UEFI and has free space on HDD so it is possible to arrange a partition for Windows without much trouble. On MBR based systems it was possible as long as you copy MBR and restore it after Windows installation. Is it possible on a UEFI system? Will I have any problems?

I have Ubuntu on my laptop. Now I want install Windows 7 in a dual-boot. How can I do this? I can't lose my Ubuntu files, and I'm afraid that I might break . Go  for UEFI only!


I'm trying to publish a large number of MXD files to my ArcGIS Server with an ArcPy script. Here's the overview of how I'm doing this  mapDoc = arcpy.mapping.MapDocument(...) con = r'C:\...' service = currentMXD[:-4] sddraft = wrkspc + '\\sdfiles\\' + service + '.sddraft' sd = wrkspc + '\\sdfiles\\' + service + '.sd' arcpy.mapping.CreateMapSDDraft(mapDoc, sddraft, service, 'ARCGIS_SERVER', con, True, 'etc') arcpy.mapping.AnalyzeForSD(sddraft) arcpy.StageService_server(sddraft, sd) arcpy.UploadServiceDefinition_server(sd, con)   Pretty much following the example code of how to publish using an MXD file. Now, I want to add WFS and Feature Access capabilities when publishing these MXDs, which seems like it should be simple because you just need to check the boxes off when publishing manually, but I can't find how to do so. Does anyone know of a way to do so?

I publish map services on a ArcGIS server using the typical arcpy script below. I need to better specify some service parameters. For example, the service should be available in WMS instead of KML, with anti-aliasing and some specific pooling parameters.  Is there a way to specify these parameters using some arcpy functions?  connection6546543 = 'C:/blabla/arcgis on myserver.eu (admin).ags' folder1116 = "Myfolder"  def publishService(mxdPath, service_name, summary, tags):     sddraft = 'C:/services/' + service_name + '.sddraft'     if os.path.isfile(sddraft): os.remove(sddraft)      # Create service definition draft     map = arcpy.mapping.MapDocument(mxdPath)     arcpy.mapping.CreateMapSDDraft(map, sddraft, service_name, 'ARCGIS_SERVER', connection6546543, True, folder1116, summary, tags)      # Analyze the service definition draft     analysis = arcpy.mapping.AnalyzeForSD(sddraft)      # Print errors, warnings, and messages returned from the analysis     print "The following information was returned during analysis of the MXD:"     for key in ('messages', 'warnings', 'errors'):         print '----' + key.upper() + '---'         vars = analysis[key]         for ((message, code), layerlist) in vars.iteritems():             print '    ', message, ' (CODE %i)' % code             print '       applies to:',             for layer in layerlist:                 print layer.name,             print      # Stage and upload the service if the sddraft analysis did not contain errors     if analysis['errors'] == {}:         print 'Create service definition...'         sd = 'E:/services/' + service_name + '.sd'         if os.path.isfile(sd): os.remove(sd)         arcpy.StageService_server(sddraft, sd)          print 'Publish service...'         arcpy.UploadServiceDefinition_server(sd, connection6546543)         print "Service successfully published"         print 'Clean sd'         if os.path.isfile(sd): os.remove(sd)     else:          print "Service publication failed: Errors during analysis."      print arcpy.GetMessages()      print 'Clean sddraft'     if os.path.isfile(sddraft): os.remove(sddraft)     Detailed solution  The detailed solution I developed with the answers is the code snippet below. It has to be inserted between the draft service creation and draft service analysis. It modifies some parameters (UsageTimeout, KML off and WMS on, etc.) but can easily be adapted to others.  import xml.dom.minidom as DOM   (...)  # change service parameters doc = DOM.parse(sddraft) keys = doc.getElementsByTagName('Key') for key in keys:     if key.firstChild.data == 'UsageTimeout': key.nextSibling.firstChild.data = 6000     if key.firstChild.data == 'WaitTimeout': key.nextSibling.firstChild.data = 60     if key.firstChild.data == 'IdleTimeout': key.nextSibling.firstChild.data = 20000     if key.firstChild.data == 'MinInstances': key.nextSibling.firstChild.data = 1     if key.firstChild.data == 'MaxInstances': key.nextSibling.firstChild.data = 1 services___ = doc.getElementsByTagName('TypeName') for service__ in services___:     if service__.firstChild.data == 'KmlServer':         service__.parentNode.getElementsByTagName('Enabled')[0].firstChild.data = 'false'     if service__.firstChild.data == 'WMSServer':         service__.parentNode.getElementsByTagName('Enabled')[0].firstChild.data = 'true'  # save changes if os.path.exists(sddraft): os.remove(sddraft) f = open(sddraft,"w") doc.writexml(f) f.close()


I am trying desperately to remember the title and author of a science fiction book for teenagers, written before 2003.  The book was about a young adult virgin who sold her physical body to have an upgrade to a synthetic body. Her "sponsor" (buyer), was the CEO/Owner of the company that made the synthetic bodies so she ended up having a top-of-the line trial body, instead of the cheap one she had payed for.   While in recuperation she is rooming with or becomes friends with another girl from a rich family who paid for her to have the same body as she was previously either paraplegic or quadriplegic.   I think it was set in the far distant future, however I for the life of me can't remember much more than the info I've given.

I read this book between 1999 and late 2004. I am pretty sure it had a blue cover and may have been published by Penguin. It was a paperback.  The story goes, as far as I can remember, that after an accident her body was too badly damaged and she was implanted into a cyborg or bionic shell, which had been cast aside by other wealthy people who upgrade their "cyborg bodies" when they get bored or for new upgrades. Undamaged real bodies were a premium and the poor could sell their healthy bodies for money to purchase older model cyborg bodies.  I think the protagonist has recurring memories or that they play a part in it somehow.


I want to align my equations in such a way that every + and - are written in one row.  I want to do it like this:  \begin{align*} &+ \left( \gamma^{r}_{y} \gammabar^{v}_{u} \gammabar^{x}_{s}  &- \gamma^{r}_{y} \gammabar^{v}_{s} \gammabar^{x}_{u} \right) \\ &- \lb \gamma^{r}_{y} \gammabar^{v}_{q} \gammabar^{x}_{s}  &+ \gamma^{r}_{y} \gammabar^{v}_{s} \gammabar^{x}_{q} \rb \\ \end{align*}  Where \gammabar is a macro for \bar{\gamma}   But if I want to do that I get an error:  Extra } or forgotten \right \end{align*}  So does anybody know what's going on there?  So I want to align not only with one &, but many &'s.

My MWE:  \documentclass{report}  \usepackage{amsmath}  \begin{document}  \begin{align} y &= a \\ =& -2c_1\bar{z}_1^2 + 2\bar{z}_1\bar{z}_2 + 2\bar{z}_2 \left ( -\bar{z}_1 -c_2z_2 - \frac{3\epsilon}{2}\bar{z}_2 -\sigma_{2,1}\cos(x_1)\Delta x_1 \notag \right. \\ \left. &- \sigma_{2,2}\Delta x_2 -\sigma_{2,3} \Delta u +c_2 \chi_2 \vphantom{\frac{1}{1}} \right ) - 2\gamma \sigma_{2,1}^2\cos^2(x_1) \Delta x_1^2 - \gamma \sigma_{2,2}^2 \Delta x_2^2   - 2\gamma \sigma_{2,3}^2 \Delta u^2 \end{align}  \end{document}   The error I get:  Extra }, or forgotten \right.   The expected result:


I have a plot like this and want to change the position of the 'tick multiplier', i.e. change where the $10^{-3}$ or $10^{-4}$ actually occurs. I don't want to change where ticks occur or remove the scaling.  \documentclass{standalone} \usepackage{amsmath,tikz,pgfplots} \begin{document} \begin{tikzpicture} \begin{axis}[scaled ticks=true] \addplot coordinates { (20000,0.0005) (40000,0.0010) (60000,0.0020) }; \end{axis} \end{tikzpicture}% \end{document}

How can I move the axis multiplier in a polar plot? In the following MWE, the axis multiplier is over the ticks and prevent the plot to be nice and readable.   \documentclass[crop=true,border=2mm]{standalone} \usepackage{pgfplots} \usepgfplotslibrary{polar} \usepgfplotslibrary{dateplot}  \usepackage{amsmath} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{graphicx}  %\pgfplotsset{compat=1.7}  \newlength\figureheight \newlength\figurewidth \setlength\figureheight{4cm} \setlength\figurewidth{4cm}  \begin{document}  \begin{tikzpicture} %[scale=1.0]     \begin{polaraxis}[%         axis on top,         width = \figurewidth,         height = \figureheight,         scale only axis,         ymin=5.e5, ymax=1.5e6,         xtick      ={0, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330},         xticklabels={0, $\frac{\pi}6$, $\frac{\pi}3$, $\frac{\pi}2$, $\frac{2\pi}3$, $\frac{5\pi}6$, $\pi$ , $\frac{7\pi}6$, $\frac{4\pi}3$, $\frac{3\pi}2$, $\frac{5\pi}3$, $\frac{11\pi}6$},         ytick = {5e5, 1.e6, 1.5e6},     ]     \addplot [data cs=polarrad, mark=*, draw=black, smooth]         table [%         col sep=comma, trim cells=true, %         x=x, y=y,] %         {mydata.dat};     \end{polaraxis} \end{tikzpicture}  \end{document}   The content of mydata.dat is as follows.  # mydata x,y 0.0000,1.1686E+06 0.0175,1.1686E+06 0.0349,1.1446E+06 0.0524,1.1165E+06 0.0698,1.1034E+06 0.0873,1.1038E+06 0.1047,1.1059E+06 0.1222,1.1317E+06 0.1396,1.1500E+06 0.1571,1.1372E+06 0.1745,1.1173E+06 0.1920,1.1218E+06 0.2094,1.1257E+06 0.2269,1.1203E+06 0.2443,1.1078E+06 0.2618,1.1043E+06 0.2793,1.1239E+06 0.2967,1.1228E+06 0.3142,1.0912E+06 0.3316,1.0909E+06   The result is shown in the following figure. As can be seen .10^6 is on the xtick=0 and makes the plot hard to read.    I have run an update on all the packages including pgfplots. However, I still see ("C:\Program Files (x86)\MiKTeX 2.9\pgfplots_1.7.tds\tex\generic\pgfplots\libs\ tikzlibrarypgfplots.polar.code.tex") in the log file, which I assume it is using compat=1.7.   Regardless of the version, Which seems solvable, is there any way to manually set the position of the axis multiplier or at least fine tune its position?  Thanks.


Which is sentence is correct? Than? Or Then?     I'd rather go running then eat    Or...      I'd rather go running than eat

I want to know the difference between “then” and “than”, when i use it and how, because the pronounce is very similar?


For integration purposes I am regularly dumping/updating the full Salesforce database to our on-premise system. To do that, I am using a Salesforce admin user with all privileges (so that we can fetch all object and items).  How can we replicate the user permissions for on-premise use? Certain users are only allowed to acccess specific account on the Salesforce plattform, and we would like to be able to check their permissions on the on-premise database dump as well.  Is there a way to regularly dump the permissions table or call a Salesforce API in real-time ("e.g. to check if user #1 can access item #33 in object "accounts").

If a user clicks 'Edit' on an opportunity which he isn't allowed to edit, the "Insufficient Privileges" page directly appears. This is good. If a user clicks 'Edit' on a custom object (which has an edit override that points to a visualforce page), he first sees the form without problems, and the "Insufficient Privileges" page only appears when he tries to save it. This behaviour is misleading for the users, because they think they can manipulate the data and put effort into it, and only afterwards they realize that this wasn't possible after all.  An idea was to check at page load if the user has edit permissions and otherwise redirect him to the "Insufficient Privileges" page.  Might there be another way? Thanks!


I was watching a tutorial on making a cup, (link in comment) and towards the end, he says make Clamp 0.98 in order to remove white spots on the image.  I added 0.99 to Clamp Direct (2.78c) and I still get the white spots on the image, and no clean cup and bottom on render. The image looks like this,      while his image looks like this     What am I doing wrong?  Screenshot of my settings in the comment.

I often use Cycles' built in Glass BSDF shader to achieve realistic refraction effects, but in many cases, it seems that Cycles' glass caustics creates an unfortunately large number of fireflies (pixels that are abnormally bright relative to their surroundings). In some models of mine, even when I render for 3000 or more samples/pixel, my final image is still covered in fireflies. While I can improve this in many cases by increasing the total amount of light available in the scene, this loses a lot of the potency of the refractive effects I'm looking for, especially in scenes with low light levels.  So my question is, how can I reduce the amount of fireflies while using Cycles' caustics without sacrificing the quality of the refractive effects?  Note: I am aware that Cycles' caustics will perform much better once Cycles has full support for bidirectional path-tracing, but it looks unlikely that that will become , unfortunately.


The equation of linear motion in a given coordinate axis (say $x$) in my text book:    And throughout my mechanics course I never encountered derivative with power higher than 2 in EOM?  Why is it so?  Does additional derivatives put on any restriction in  a physical sense which although mathematically constructable but not physically possible? (just like imaginary roots in quadratic equation in certain problems had imaginary or negative roots of time)  EDIT: It turns out that there exist two anser which adresses the problem in terms of lagrangian mechanics  Is there any equivalent explanation from the point of view of Newtonian Dynamics?

Why is the Lagrangian a function of the position and velocity (possibly also of time) and why are dependences on higher order derivatives (acceleration, jerk,...) excluded?  Is there a good reason for this or is it simply "because it works".


I want the user to input n numbers of his wish and write a program in java to find the average using arrays. I came up with the following program, but there seems to be a problem when i run it:    Exception in thread "main" java.lang.NullPointerException at wert.main(wert.java:12)  This is the code in question:  import java.util.Scanner; public class wert {  public static void main(String[] args) {     Scanner sc = new Scanner(System.in);     int gucci[] = null;      System.out.print("Enter the length\n");     int n = sc.nextInt();     System.out.println("enter the numbers : ");     for(int i=0;i<n;i++){          int k = sc.nextInt();         gucci[i] = k;         }     int m = average(gucci);     System.out.println(m/n);  }     public static int average(int x[]){         int total = 0;         for(int f: x){             total =+ f;         }         return total;     }    }   I'm sorry if I am asking a really basic question. I started learning java on my own a few days back.

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?


From      In principle, a quantum radar functions like a regular radar — only   that instead of sending out a single beam of electromagnetic energy,   it uses two split streams of entangled photons. Only one of these   beams is sent out, but due to a quirk of quantum physics both streams   will display the same changes, despite being potentially miles apart.   As a result, by looking at the stream which remains back home it’s   possible to work out what has happened to the other beam.   Wouldn't this imply faster-than-light information transfer? Is there any way that the interactions of a remote particle can influence a local entangled particle?

As I understand it (from a lay physics perspective), quantum entanglement has been experimentally demonstrated - it is a reality. As I understand it, you can measure something like the spin of an electron and know that its entangled pair will, in that same instant, no matter where in the universe it is, have the opposite spin.   This would not seem to have any utility as the foundation of a superluminal communications device. Is this true, or has it been established that is there some aspect of quantum entanglement that can ultimately lead to the development of such a device.  In other words: is superluminal communication via quantum entanglement an open scientific question, has it been settled as an impossibility, or is it currently more of an engineering problem than a scientific one?


I am using ubuntu 14.04  LTS for a week only. First, there was a password. Then I made the setting 'log in without a password.' After 2 days I again made a password. It is required for authentication nd installing apps. But when I log in to ubuntu, its not needed ! I can log in without it. There's no option for password. Btw, I turned automatic login off, and changed the password several times but no result come out.  What can I do ?

When I first installed Ubuntu I choose NOT to ask me for a password at login. That was ok for that moment cause it didn't ask me any password at login. But now I want to be asked for a login password. I changed the settings to Not start automatically but it doesn't work. My Ubuntu doesn't ask me password at login. What should I do now?  In the automatic login box (in the user accounts setting window) I have it checked to off (0 or Off), the thing is that my LightDM login screen gives me only a "Start Session" button below my user name, instead of the usual password field.


Is there a reason to prefer either string concatenation or invoking toString when converting objects to string representations?  Does string concatenation cause the object's toString method to be invoked?  String s; Properties p = System.getProperties(); s = p.toString(); s = "" + p;

I used to use the implicit call of toString when wanting some debug info about an object, because in case of the object is null it does not throw an Exception.  For instance:    System.out.println("obj: "+obj);   instead of:  System.out.println("obj: "+obj.toString());   Is there any difference apart from the null case? Can the latter case work, when the former does not?  Edit: What exactly is done, in case of the implicit call?


I am trying to use Spring Boot to read a file stored in GCS using this tutorial:  My code as follows: Resource gcsFile = resourceLoader.getResource(gcsPath);             //InputStream inputStream = gcsFile.getInputStream();             return StreamUtils.copyToString(                     gcsFile.getInputStream(),                     StandardCharsets.UTF_8);  resourceLoader is injected as a dependency using @Autowired annotation. The gcsPath variable is a String to the gcs file location (example: gs://REPLACE_WITH_YOUR_BUCKET/my-file.txt). I get the below exception: java.lang.NullPointerException: null         at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:878)         at com.google.cloud.storage.BlobId.of(BlobId.java:109)         at org.springframework.cloud.gcp.storage.GoogleStorageResource.getBlobId(GoogleStorageResource.java:108)         at org.springframework.cloud.gcp.storage.GoogleStorageResource.resolve(GoogleStorageResource.java:113)         at org.springframework.cloud.gcp.storage.GoogleStorageResource.getInputStream(GoogleStorageResource.java:167)   During debugging, I found that the following line is what triggers this exception: InputStream inputStream = gcsFile.getInputStream(); I have not been able to figure out how and why this is happening. Can someone please help?


How to display a single column values ofsql server in a single line or row.  and seperating each values by * symbol.  i tried this:  SELECT GROUP_CONCAT(ordernum SEPARATOR ' , ') AS File_viewer FROM Functional WHERE OrderNum Order by asc;   my column is:  **ORDERNUM** 00 NULL 00 NULL ZZ 2UN ZZ 263923720 NULL 1234 ^ 0001 000000901 0 o :

Consider a database table holding names, with three rows:  Peter Paul Mary   Is there an easy way to turn this into a single string of Peter, Paul, Mary?


I'm trying to prove Exercise 3.5 in Set Theory by Thomas Jech: $$ \Gamma(\alpha\times\alpha) \leq \omega^\alpha $$ where $\Gamma(\alpha\times\beta)=\operatorname{otp}(\{(\zeta,\delta)\mid(\zeta,\delta)\lt(\alpha\times\beta)\})$  and  $$(\zeta,\delta)\lt(\alpha,\beta) \iff \begin{cases}   \max(\zeta,\delta)\lt \max(\alpha,\beta)\\       \max(\zeta,\delta)= \max(\alpha,\beta)\text{ and } \zeta\lt\alpha\\   \max(\zeta,\delta)= \max(\alpha,\beta)\text{ and } \zeta=\alpha \text{ and }\delta\lt\beta \end{cases}$$ Here's what I've tried so far:   If $\alpha=0$ , then $\Gamma(\alpha\times\alpha) = 0\le1=\omega^0$. If $\alpha>0$ is finite, then $\Gamma(\alpha\times\alpha)$ is also finite, hence $\Gamma(\alpha\times\alpha) \lt \omega \le\omega^\alpha$.   Then I'm not too sure where to go from here

This is from exercise 3.4 of Thomas Jech's "Set Theory", stated:  "Show that $\Gamma(\alpha\times{\alpha})\leq{\omega^{\alpha}}$. Thus $\Gamma(\alpha\times{\alpha})=\alpha$ for all indecomposable ordinals $\alpha$".  $\Gamma$ is the Gödel pairing function on ordinals. An ordinal $\alpha$ is indecomposable if there are no $\beta<\alpha$ and $\gamma<\alpha$ such that $\beta+\gamma=\alpha$. The first part is trivial, since it holds for $\alpha=0$, and the function $\omega^{\alpha}$ is normal in the variable $\alpha$. I'm having trouble to show the second part, the only connection I see is the fact that $\gamma$ is indecomposable if and only if $\gamma=\omega^{\alpha}$ for some $\alpha$, which is easily proven from Cantor's normal form theorem. Any help will be appreciated.


This is a Homework question i'm struggling with.  T is a linear map over C. Prove: if T and T* have the same Eigen-vectors then T is normal.  I've been breaking my back over this one... A complete solution would be nice but any help would do. thanks. Michael

Let $V$ be a finite-dimensional inner product space over $\mathbb{C}$ and $T: V \to V$ a linear transformation.   Show that if every eigenvector of $T$ is also an eigenvector of $T^{*}$ then $T$ is a normal.   We need to show that $\forall v \in V,\ TT^*v=T^*Tv$.  I started by picking $v$ to be an eigenvector of $T$, hence $Tv=\lambda_1 v$, and $T^*v=\lambda_2 v$. Therefore: $$TT^*v=T(\lambda_2 v)=\lambda_2 Tv=\lambda_1 \lambda_2 v=...=T^*Tv$$  But I'm stuck when $v$ is not an eigenvector.  (Also, this question is taken from a chapter about Jordan forms, but I can't see how it relates)


I came across this sentence in an English exam: "John, there is a Mr. Smith on the phone for you", My question is that is it the right way to put it in a way like the sentence above, or it should be "John, there is Mr. Smith on the phone for you"?

There is the following sentence in the scene a reputed lawyer, Thomas Cohen gives advice to 16-year old client William Kane, the son of deceased bank owner on the issue of inheritance of his father’s property in Jeffery Archer’s popular fiction, “Kane & Abel.”     “Mr. Cohen continued. ‘The answer to your second question is that you   have no personal or legal obligation to Mr. Henry Osborne. Under the   term of your father’s will, your mother is a trustee of his estate   along with a Mr. Alan Lloyd and a Mrs. Millie Preston, your surviving   godparents, until you come of age at twenty-one.’"   I wonder why it is a Mr. Alan Lloyd and a Mrs. Millie Preston. Here Mr. Alan Lloyd and Mrs. Millie Preston are too obvious to both parties concerned, and different from the case of being told by your secretary, "A phone from a Mr. Smith Brown.”  What significance is added to by prefixing ‘a’ to the name in this particular case?


I heard that Stack Overflow's Question/Answer data is downloadable.  How can I get it?

I see a lot of talk around here regarding the Stack Overflow public data dump.  Where is it? How can I play with it?


So I typically run the following to set a custom DNS server when I am on WiFi:   networksetup -setdnsservers Wi-Fi <desired-dns-server-here>   However, I would like to know how to unset custom DNS servers and revert to DHCP provided DNS.  article from 2015 says that running networksetup -setdnsservers Wi-Fi should do this, but on macOS 10.15 that results in ** Error: The amount of parameters was not correct.  Any ideas how this can be done?

I'm looking to script a temporary DNS server change to override the DHCP response I get from the network. I've figured out I can use networksetup but once we're done testing. Before I push to production, I figure I should know how to undo this.  How can I script to clear these changes and restore the settings the network provides now as if I never ran the following script?  networksetup -setdnsservers Wi-Fi "8.8.8.8" "8.8.4.4"   It's not feasible to save any the previous settings and I'm looking to remove the setting so that the actual new values can be retrieved from the network as opposed to saving what the settings were previously so I don't save an old value that is no longer correct.  Basically, I'm looking to ipconfig /renew on macOS.


I am a new learner concerning English sounds. Could someone help me?  Does the letter t at the end of word but this word being connected with next one, is it also pronounced like a glottal stop? For example, that it was ......, the last "t" in that.

It's just strange to me because "t" is pronounced with the front teeth, while the glottalized "t" is produced with the back of the throat; that seems like quite a noticeable journey that couldn't have happened all at once.  If I'm correct, do linguists have any clue what intermediate steps would have been taken, and can someone demonstrate a couple of those pronunciations with English words?


Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


Let $f:\mathbb C\to\mathbb C$ is entire function. And $f(z+1)=f(z)$ and $f(z+i)=f(z)$ then what can you say about $f$ ?  I guessed that it must be a constant because evaluating the function on a translation of $z$ by 1 unit and $i$ result the same. so it must be a constant. But I need a concrete argument. Thanks in a bunch.

So the problem states that if $f(z)$ is entire, and satisfies the relation $f(z+i) = f(z)$ and $f(z+1) = f(z)$, show that $f(z)$ is constant. So I was thinking that since any point in $\mathbb{C}$ can be written as $\alpha * 1 + \beta * i $ we can say that $f(z + z_0) = f(z) $ in which case it is constant, but I'm having trouble breaking down the steps and using the fact that $f$ is entire, which makes me feel like I'm missing something. What should I review to figure this out?


Please let me know how to convert salesforce datetime() to Unix format in apex.  Thanks

I found the question about converting epoch time to normal time, but I'm having two problems:   When I run DateTime.newInstance(1391529600 * 1000) I am getting the wrong answer I want to convert normal time to epoch time   1: I have been typing the following into Execute Anonymous:  system.debug(DateTime.newInstance(1391529600 * 1000));   By my calculations (and some websites I found) that should give me 4 Feb, 2014, 16:00:00 GMT.  Apex gives me      1969-12-31 12:56:36   Clearly, this is incorrect (and it's even before 1/1/1970). Can anyone replicate my situation?  2: I also want to change the current datetime (GMT) to epoch time, returning the number of seconds or milliseconds since 1/1/1970. I could break things into parts, but that seems an awful lot of script statements to do something that should be fairly easy, I'd hope.  Thanks for the help!


i do have a problem witch catching an .click() event on an generated section which is created after a click of another div.  the code looks something like this.  $('#all_events_entries').append(     '

test

'  );    After this happens, the specific sections are shown in the right way and i try to catch the click events on this section like this...  $(document).ready(function() {         $('.event').click(function(e) {          e.preventDefault();         alert("test");          }); });   The Problem is, this event never get executed. Is it even possible to catch a click event of an section which not exists after the first load?  Regards!

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.


Let $a_n$ be a sequence such that n $\in{N}$ and $a_n$ $\ne 0$. Assume that $\lim_{n\to \infty}a_n=0$.   Show that $\lim_{n\to \infty}(1+a_n)^{1/a_n}=e$. Really having a tough time with this one. Can anyone help? This question is in the subsequential limit problem section.

What would be the nicest proof of the following theorem:  If $\lim\limits_{n \rightarrow \infty} a_{n} = \infty$, then $\lim\limits_{n \rightarrow \infty} \left(1 + \frac{1}{a_{n}} \right) ^ {a_{n} } = e$. If $\lim\limits_{n \rightarrow \infty}b_{n} = 0$, then $\lim\limits_{n \rightarrow \infty} \left(1 + b_{n} \right) ^ {\frac {1} {b_{n}} } = e$.  I somehow failed to find a proof here on the website and in the literature.


Let $H$, $K$ be groups, and suppose that $H \cong K \times H$. Does it necessarily follow that $K$ is trivial?

Aluffi II.3.4 asks the reader to find groups $G$ and $H$ such that $G\times H\cong G$ but $H$ is not trivial. I believe I have found a solution, but would like someone to check. Also, is there a more elementary example? I tried mucking around with $S^1\times (\Bbb Z/2\Bbb Z)$, which feels like it should be isomorphic to $S^1$ (the unit circle under complex multiplication), but I kept getting confused.  My solution  Let $H$ be a non-trivial group and let $G=H^\omega$. Then $\phi\colon H\times G\to G$ defined by $$\phi(h,g)_n=\begin{cases} h &n=0\\ g_{n-1} &n\ne 0 \end{cases}$$ looks like a group isomorphism to me. It's obviously a bijective function, and \begin{align*} \phi((h_1,g_1)(h_2,g_2))_n &=\phi(h_1h_2,g_1g_2)_n \\ &=\begin{cases} h_1h_2&n=0\\ (g_1g_2)_{n-1}&n\ne 0 \end{cases}\\ &=\phi(h_1,g_1)_n\phi(h_2,g_2)_n \\ &=(\phi(h_1,g_1)\phi(h_2,g_2))_n. \end{align*}


I have an issue for which the work around would be to start the application in X instead of headless. How do I make sure the app is executed on the desktop, even if I run the command from a remote ssh connection.

Once upon a time,  DISPLAY=:0.0 totem /path/to/movie.avi   after ssh 'ing into my desktop from my laptop would cause totem to play movie.avi on my desktop.  Now it gives the error:   No protocol specified Cannot open display:    I reinstalled Debian squeeze when it went stable on both computers, and I guess I broke the config.   I've googled on this, and cannot for the life of me figure out what I'm supposed to be doing.   (VLC has an HTTP interface that works, but it isn't as convenient as ssh.)  The same problem arises when I try to run this from a cron job.


I'm not having any problems fixing this. I'm creating a game and I constructed a camera to follow a player when they are moving but when I use the method translate from the Graphics2D class I get a null pointer.  This problem doesn't happen all the time, sometimes when I run the game the error occurs?  All objects are created for Gr  Exception in thread "Thread-3" java.lang.NullPointerException at game.Game.render(Game.java:172) at game.Game.run(Game.java:126) at java.lang.Thread.run(Thread.java:745)   It's pointing at this line here.      g2d.translate(cam.getX(), cam.getY());     In my render method.      private void render() {     BufferStrategy bs = this.getBufferStrategy();     if (bs == null) {         this.createBufferStrategy(3);         return;     }      Graphics g = bs.getDrawGraphics();     Graphics2D g2d = (Graphics2D) g;       g.setColor(Color.BLACK);     g.fillRect(0, 0, WIDTH, HEIGHT);      g2d.translate(cam.getX(), cam.getY());            handler.render(g);      g2d.translate(-cam.getX(), -cam.getY());      if (gameState == STATE.GAME) {         hud.render(g);     } else if (gameState == STATE.MENU || gameState == STATE.HELP ||    gameState == STATE.END) {         menu.render(g);     }     g.dispose();     bs.show(); }   Any ideas?  cam is coming from this code:  public Game() {      tex = new Texture();      handler = new Handler();     hud = new HUD();     menu = new Menu(this, handler, hud);     this.addKeyListener(new KeyInput(handler));     this.addMouseListener(menu);      new Window(WIDTH, HEIGHT, "Let's Build A Game", this);      spawner = new Spawn(handler, hud);  //      loader = new BufferedImageLoader(); //      background = loader.loadImage("/level.png"); //       //      loadImageLevel(background);      cam = new Camera(0, 0);      if (gameState == STATE.MENU) {         handler.createMenuParticle();     } else {         handler.clearEnemies();     } }   This is the camera class I use.  public class Camera {  private float x, y;  public Camera(float x, float y) {     this.x = x;     this.y = y; }  public void tick(GameObject player) {     x = -player.getX() + (Game.WIDTH / 2);     y = -player.getY() + (Game.HEIGHT / 2); }  public float getX() {     return x; }  public void setX(float x) {     this.x = x; }  public float getY() {     return y; }  public void setY(float y) {     this.y = y; } }

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 am analyzing ARIMA or multiple regression model. $Y= X_1 + X_2 + X_3 + X_4$  Can I have the log on Y and square root on X1 and square root on X2, at the same time?  That is,   $\log Y = \sqrt{X_1} + \sqrt{X_2} + X_3 + X_4$  If yes, how can I interpret the results?

When transforming variables, do you have to use all of the same transformation? For example, can I pick and choose differently transformed variables, as in:   Let, $x_1,x_2,x_3$ be age, length of employment, length of residence, and income.  Y = B1*sqrt(x1) + B2*-1/(x2) + B3*log(x3)   Or, must you be consistent with your transforms and use all of the same? As in:   Y = B1*log(x1) + B2*log(x2) + B3*log(x3)    My understanding is that the goal of transformation is to address the problem of normality. Looking at histograms of each variable we can see that they present very different distributions, which would lead me to believe that the transformations required are different on a variable by variable basis.   ## R Code df <- read.spss(file="http://www.bertelsen.ca/R/logistic-regression.sav",                  use.value.labels=T, to.data.frame=T) hist(df[1:7])      Lastly, how valid is it to transform variables using $\log(x_n + 1)$ where $x_n$ has $0$ values? Does this transform need to be consistent across all variables or is it used adhoc even for those variables which do not include $0$'s?  ## R Code  plot(df[1:7])


Is there any way to remove the footnote hyperlink from the table of contents ?  My MWE :  \documentclass{book} \usepackage{hyperref}  \begin{document} \tableofcontents \chapter{Test \protect \footnote{test of footnote}} \section{Section One } \section{Section two} \chapter{Test \protect \footnote{test of footnote}} \section{another section} \end{document}

This is a question that arose in the comments here:   I normally hide footnotes from the TOC by doing this:  \section[title]{title\footnote{This is a footnote.}}.   This works in a lot of document classes (memoir, article, ...), but not in all of them. amsbook, for example, uses the optional argument only for the running heads so the footnote mark still ends up in the TOC. So what is the 'universal solution'?


I don't think it would be a bad idea to allow tag "locking". The trouble is, we have some deprecated tags which we don't want to accept new questions for, but we can't just burninate mindlessly. The primary example of this is the  tag. It's supposed to be obsolete, but new questions flood in every day because people don't take the time to read the tag description.  Locking a tag (or alternatively, deprecating it) would allow the removal of such tags from questions but not addition. As a fallback, questions can still be rolled back to a state where they possessed the tag in case a poor edit is made, but it cannot be added manually.  Without such a feature, I fear that the homework tag is here to stay.

Based on my answer , I would like to propose the implementation of a tag black list.  The black list should contain a list of tags that should NOT be used on the site and disallow people with tagging rights to use these tags, for example the case of using the belongs-on tags.  I would also suggest increasing the tagging rep limit however this was previously covered .   Additional Options  As mentioned by  the list should only be accessible by moderators and possibly 10K moderators to ensure that the list is kept tidy. However for 10k moderators a voting process will be put in place to add a tag to the blacklist.  The list should also be updated when moderators merge tags. The removed tag should automatically be added to the black list.  Blacklisted tags can appear as strikethroughs on the tag field when editing or adding a new question, and be validated accordingly.  Additional Nice to Have  When tags are edited they should not bump questions, as this ends up creating a lot of noise on the homepage.


If he destroyed only Future Universe 7 then other 11 Universes do not have a ruler God now because he went to the past, isn't that very bad?  If he destroyed all 12 Universes then why did he do that if only Universe 7 was polluted by Zamasu?

I'm confused about what Zeno destroyed for killing Zamasu, did he destroy just the Earth, the entire Universe, or the 12 universes?


I'm running Ubuntu 20.04 on a Dell Inspiron with a Broadcom  BCM43142 network controller and it does not show all Wi-Fi networks, specifically from a mobile phone. Please help me solve this issue, thanks!

I'm having serious problems installing the Broadcom drivers for Ubuntu. It worked perfectly on my previous version, but now, it is impossible.   What are the steps to install Broadcom wireless drivers for a BCM43xx card?  I'm a user with no advance knowledge in Linux, so I would need clear explanations on how to make, compile, etc.    lspci -vnn | grep Network showed:   Broadcom Corporation BCM4322 802.11a/b/g/n Wireless LAN Controller [14e4:432b]      iwconfig showed:  lo        no wireless extensions. eth0      no wireless extensions.   NOTE: Answer below is updated every time new information is added and confirmed working.


Let $f$ be a continuously differentiable function on $\mathbb{R}$ such   that both the limits $\lim_{x \rightarrow \infty} f(x)$ and $\lim_{x > \rightarrow \infty} f'(x)$ exist and are finite. Is $\lim_{x > \rightarrow \infty} f'(x) = 0$ necessarily?   This is true. Let $\lim_{x \rightarrow \infty} f'(x) = M$ and $\lim_{x \rightarrow \infty} f(x) = L$. Suppose $M > 0$, there exists some $A_1 \in \mathbb{R}$ such that for all $x > A_1$,  $$ f'(x) > \frac{M}{2}$$ Given $\epsilon = \frac{M}{4} > 0$, there exists $A_2 \in \mathbb{R}$ such that whenever $x > A_2$, $$|f(x) - L| < \frac{M}{4}$$ For $x, y > A_2$, we have  $$ |f(x) - f(y)| \leq |f(x) - L| + |f(y) - L| < \frac{M}{2}$$ Let $A = \max\,\{A_1, A_2\}$. Take $x > A$, then applying LMVT on $[x, x+1]$, there exists some $c \in (x, x+1)$ such that $$ |f(x+1) - f(x)| = |f'(c)| > \frac{M}{2}$$ But as $x > A_2$, $$|f(x + 1) - f(x)| < \frac{M}{2}$$ This is a contradiction, so $M > 0$ must be false.  Similarly, we can prove that $M < 0$ does not hold. Thus, $M = 0$.  Does this proof work? Is there a cleaner way to do this?

I've been trying to solve the following problem:  Suppose that $f$ and $f'$ are continuous functions on $\mathbb{R}$, and that $\displaystyle\lim_{x\to\infty}f(x)$ and $\displaystyle\lim_{x\to\infty}f'(x)$ exist. Show that $\displaystyle\lim_{x\to\infty}f'(x) = 0$.  I'm not entirely sure what to do. Since there's not a lot of information given, I guess there isn't very much one can do. I tried using the definition of the derivative and showing that it went to $0$ as $x$ went to $\infty$ but that didn't really work out. Now I'm thinking I should assume $\displaystyle\lim_{x\to\infty}f'(x) = L \neq 0$ and try to get a contradiction, but I'm not sure where the contradiction would come from.   Could somebody point me in the right direction (e.g. a certain theorem or property I have to use?) Thanks


In the android app I sometimes receive inbox messages that I have already seen on the web interface. However, the only way that I seem to be able to set their status to be unread is to click on them.  Better: menu option to "Mark all as read"  Best: way to mark individual message as read (swipe to the right?)

In the Android app, can we have some option to mark a read notification to unread? I know that this option is not available in the web version of Stack Exchange sites. But sometimes I open the notification in the app and it opens the post, but sometimes I can't see the exact reply to my comment or where my name is mentioned using the app.   And I want those comments to be read from the web version of the Stack Exchange site. Sometimes I forget about replying to a comment since the notification is already marked as read. So I want to mark the notification as unread and have it as a new notification displayed in the mobile app and the web version too.


I know you can turn your single player world into a Minecraft Realm world but how do you do it the other way around?

I have played on my friend's Survival Realm for ~3 months and he was going to stop paying for the realm so I was wondering is there any way to get that world for my Personal Client.


Let us consider scalar field theory. Why usually we do not have a linear term in the potential, like $$V(\phi)=a\phi+\frac{1}{2}m^2\phi^2+\frac{1}{4!}\lambda\phi^4,$$ or equivalently, after a field redefinition,  $$V(\phi)=\frac{1}{2}m^2\phi^2+\frac{1}{4!}\lambda(\phi-b)^4?$$  This kind of potential is renormalizable and energy bounded from below. But I have never seen any serious discussions on this type of theory. Are there troubles with this potential?  PS: I have seen the discussions when there is a cubic term $g\phi^3$ in the potential. This happens in, for example, false vacuum decay.

I was told when first learning QFT that linear terms in the Lagrangian are harmless and we can essentially just ignore them. However, I've recently seen in the linear sigma model, \begin{equation}  {\cal L} = \frac{1}{2} \partial _\mu \phi _i \partial ^\mu \phi _i - \frac{m ^2 }{2} \phi _i \phi _i  - \frac{ \lambda }{ 4} ( \phi _i \phi _i ) ^2  \end{equation}  with $m ^2 =-\mu^2 > 0$, adding a linear term in one of the fields $\phi_N$, does change the final results as you no longer have Goldstone bosons (since the $O(N)$ symmetry is broken to begin with).   Are there any other effects of linear terms that we should keep in mind or is this the only exception of the "forget about linear terms" rule?


As the title states, is there a way to connect to a WiFi device (my drone), yet use another app on 4G? Right now when I'm connected to my drone using WiFi, I can't use 4G, but is there a work around?

When I turn WiFi on, my 3G connection shuts down, which is fine in most cases. However, I need to connect to a LAN at work that is not connected to the internet and I'd prefer not to lose my data connection when I connect to the work intranet. How can I keep both connections active? Ideally, I could limit this desired behavior to this one SSID because I want it to continue to operate with the default behavior for all other WiFi connections.  If that can't be done, prefer a solution that is easy to toggle on and off. I'm using a Samsung Galaxy Nexus (Verizon Wireless) on CyanogenMod 9.


I installed Ubuntu 20.04 on a Dell Latitude laptop. After a few minutes, the screen suddenly rotated 90 degrees to the right. It just seemed to have happened on its own. Possibly shortly after installing Ubuntu base/firmware updates that were suggested by the system (from the official repository).  taught me how to rotate it back. The problem is that it doesn't stick. The screen still rotates occasionally, seemingly on its own. Even when it's ok, when I log off - the user selection screen is rotated. I found a "Lock Screen Rotation" option in the top-right system menu, but it doesn't seem to have an effect. It happened shortly after I installed Ubuntu, on a fairly clean system, with no special customizations or tweaks. Does anyone know how to fix this?

In Ubuntu 17.04 there was 'Rotation' menu in Display tab. But now in new version of Ubuntu, there's still a Display tab but no more rotation menu. Now I can't turn that off again since I upgraded to 18.04 LTS.


Let $u$ be a solution of $\Delta u=u^3-u$ on a bounded domain $\Omega$. I want to show that $u\in[-1,1]$ throughout $\Omega$ and find out if $u$ can attain the values $-1,1$.  This is an exercise from Rogers - "An Introduction to PDEs". I assume that the problem can be solved using some form of the maximum principle for elliptic equations as this exercise is from this section.  I wrote the equation in a form for which the maximum principles were stated, that is $Lu=\Delta u + u =u^3$  corresponding to the general form of the equations treated in this chapter $$Lu=a_{ij}(x)\frac{\partial^2 u}{\partial x_i\partial x_j}+b_i(x)\frac{\partial u}{\partial x_i}+c(x)u$$  where Einstein Summation is used. This means for my equation that $c=1,b=0$ and $a_{ij}=\delta_{ij}$. So we have a semilinear elliptic equation.  I am stuck here, as most of the theorems require that $Lu\le 0$ or $Lu\ge0$ to begin with. And even if a condition like this was satisfied, I am unsure of how to show that the range lies in an interval.

Let us consider that $u\in C^2(\Omega)\cap C^0(\Omega)$ and satisfying the following equation .  $\Delta u=u^3-u , x\in\Omega$ and   $u=0 $   in  $\partial \Omega$  $\Omega \subset \mathbb R^n$ and bounded .   I need hints to find out what possible value $u$ can take ?  Thank you for ur hints in advance .


This is my Fragment's Code:   EFragment public class PreviewFragment extends Fragment {     @Inject Bus bus;     @Inject HorstDb db;      //@ViewById(R.id.preview_text_view)     TextView previewTextView;      public PreviewFragment() {}      @Override public void onCreate(Bundle bundle)     {         super.onCreate(bundle);         ((HorstApp)getActivity().getApplication()).getComponent().inject(this);     }      @Override public View onCreateView(LayoutInflater inf, ViewGroup parent, Bundle args)     {         super.onCreateView(inf, parent, args);         View result = inf.inflate(R.layout.fragment_preview, parent, false);         previewTextView = (TextView) result.findViewById(R.id.preview_text_view);         return result;     }      @Override     public void onResume() { super.onResume(); bus.register(this); }     @Override     public void onPause() { super.onPause(); bus.unregister(this); }      @Subscribe     public void onTemplateSelected(TemplateSelected se)     {          Cursor c = db.getReadableDatabase().query("templates", null, "_id = ?",                                                                                new String[] { Long.toString(se.id) },                                                                                null, null, null);          if(c.moveToFirst())         {             previewTextView.setText(c.getString(c.getColumnIndex("content")));         }         c.close();     } }   onTemplateSelected will get called in onResume via Otto. This works and previewTextView will be non-null. The following version does not work, because previewTextView is null also I'am in the innermost lifecyle of an fragment and I am using @ViewsById. The difference is that I do not manually overload onCreateView, instead I'm using @EFragment and @ViewById to get a reference to the TextView.  @EFragment(R.layout.fragment_preview) public class PreviewFragment extends Fragment {     @Inject Bus bus;     @Inject HorstDb db;      @ViewById(R.id.preview_text_view)     TextView previewTextView;      public PreviewFragment() {}      @Override public void onCreate(Bundle bundle)     {         super.onCreate(bundle);         ((HorstApp)getActivity().getApplication()).getComponent().inject(this);     }      @Override     public void onResume() { super.onResume(); bus.register(this); }     @Override     public void onPause() { super.onPause(); bus.unregister(this); }      @Subscribe     public void onTemplateSelected(TemplateSelected se)     {          Cursor c = db.getReadableDatabase().query("templates", null, "_id = ?",                                                                                new String[] { Long.toString(se.id) },                                                                                null, null, null);          if(c.moveToFirst())         {             previewTextView.setText(c.getString(c.getColumnIndex("content")));         }         c.close();     } }   This is using the Fragment class from the Support library.  Any hints why the annotations don't work and previewTextView is null in the second example are welcome.

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 am trying to get decimal part of reel number and assign it to int variable.  float x= 1.4, y, z; y=x-(int)x; z=y*10; int a; a=z; printf("\n y : %.10f \n a : %d\n", y, a);   output :  y : 0.3999999762           a : 3  why it is not y: 4.0000000000 and a : 4 ?

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


Athough discussion on that question is  (), it seems that larger spaces after the end of a sentence is preferable in English. By default, LaTeX puts wider spaces after a period (full stop).  I took the habit of escaping spaces (i.e., writing i.e.\, or to make it more clear, i.e.\␣) after    Latin locutions, as   etc. cf.  Mathematical expressions, as    s.t. (such that) w.r.t. (with respect to) resp. (respectively)    However, according to , which quotes Chapter 14 of the Texbook, and according to any bbl file, spaces after names initial should not be escaped. That is, one write  Donald~E. Knuth   and not  Donald~E.\ Knuth   I'm confused: shouldn't that space be escaped as well?

Sometimes I found that writing just "J. Doe" may lead, in a justified line with few words, to a big space between the initial and the surname. Using J.\,Doe looks ok but I would like to know if there is a general rule for spacing between initials and surnames.


In general the pages of a book are white and the words of the book are black    Why is it not the other way around     What are the possible reasons that books were designed this way ,   Why is the black word white background favoured over white word black background??

Are there any reasons to avoid using white text on a black background?


I am trying to find the partial derivative of univariate normal cdf w.r.t $\sigma$. I just need some direction. So far I have gotten this:  $\frac{\partial }{\partial \sigma}\Phi(x,\mu,\sigma^2) = \frac{\partial }{\partial \sigma} \displaystyle\int_{-\infty}^x \frac{1}{\sqrt{2\pi}}\exp\left(-\ln(\sigma)-\frac{(x-\mu)^2}{2\sigma^2}\right)dx $  $ = \displaystyle\int_{-\infty}^x\frac{\partial }{\partial \sigma}\frac{1}{\sqrt{2\pi}}\exp\left(-\ln(\sigma)-\frac{(x-\mu)^2}{2\sigma^2}\right)dx$  $ = \displaystyle\int_{-\infty}^x\frac{1}{\sqrt{2\pi}}\exp\left(-\ln(\sigma)-\frac{(x-\mu)^2}{2\sigma^2}\right)\times\left( -\frac{1}{\sigma}+\frac{(x-\mu)^2}{\sigma^3}\right)dx$  $ = \displaystyle\int_{-\infty}^x -\frac{1}{\sqrt{2\pi}\sigma^2}\exp\left(-\frac{(x-\mu)^2}{2\sigma^2}\right) + \frac{(x-\mu)^2}{\sqrt{2\pi}\sigma^4}\exp\left(-\frac{(x-\mu)^2}{2\sigma^2}\right) dx$  I don't know how to proceed from there.

We normally calculate the derivative of normal density w.r.t its parameters, mean and variance. But can we calculate the derivative of normal distribution wrt the parameters(not the variable, I know the derivative wrt to the variable gives the density)? If yes, how do we calculate that?


Does by 2010 for example means before 2010? I read a post here that by Tuesday means before Tuesday. I would like to know are they the same?  Best,

1.In 1582, scientists pointed out that the calendar was 10 days behind the sun      2.By the year 1582, scientists pointed out that the calendar was 10 days behind the sun.   I wanted to know the difference between "by the year 1582" and "in 1582".


i got a big trouble this is my first day with ubuntu.  while installing ubuntu the participation of the hard disk was deleted and it contains a big project ( i worked on that project about 5 months and i have no copy for it.). please help me. is there any way to return my project. bad starting with ubuntu :'(  tell me is there any way to return it. i search for programs to return files but they are only for windows. and that project for the 08 of October so i need it immediately.

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.


I built an amazing underground house but accidentally fell out of the world. How do I get my coordinates at a specific moment in time so I can get back to my house without scouring the entire world?  I need to know exactly where I was at a certain tick in Minecraft. How do I determine this?

I wandered too far to go look for sheep and now I'm on a completely different island.  How do I find my way back to my house?


I have this piece of code, and I would like to know why the reference of my variable x is not modified ? It still points to the first object assigned:  public class HelloWorld{   public static void main(String []args){     Object x = new Object();     Object y = x;     mutate(x);     System.out.println(Integer.toHexString(x.hashCode()));     System.out.println(Integer.toHexString(y.hashCode()));     System.out.println(x == x); // true     System.out.println(x == y); // true  }   public static void mutate(Object x) {      x = new String();  }   }

I always thought Java uses pass-by-reference. However, I've seen a couple of blog posts (for example, ) that claim that it isn't (the blog post says that Java uses pass-by-value). I don't think I understand the distinction they're making. What is the explanation?


while i was reading about namespacing and scopping in python, i read that   -the innermost scope, which is searched first, contains the local names -the scopes of any enclosing functions, which are searched starting with the nearest enclosing scope, contains non-local, but also non-global names -the next-to-last scope contains the current module’s global names -the outermost scope (searched last) is the namespace containing built-in names   but when i tried this :  def test() :     name = 'karim'      def tata() :         print(name)         name='zaka'         print(name)     tata()   i have received this error :  UnboundLocalError: local variable 'name' referenced before assignment   when the statement print(name) the tata() function will not find name in the current scope so python will go up in scope and find it in test() function scope no??

The following code works as expected in both Python 2.5 and 3.0:  a, b, c = (1, 2, 3)  print(a, b, c)  def test():     print(a)     print(b)     print(c)    # (A)     #c+=1       # (B) test()   However, when I uncomment line (B), I get an UnboundLocalError: 'c' not assigned at line (A). The values of a and b are printed correctly. This has me completely baffled for two reasons:   Why is there a runtime error thrown at line (A) because of a later statement on line (B)? Why are variables a and b printed as expected, while c raises an error?   The only explanation I can come up with is that a local variable c is created by the assignment c+=1, which takes precedent over the "global" variable c even before the local variable is created. Of course, it doesn't make sense for a variable to "steal" scope before it exists.  Could someone please explain this behavior?


In order to make clients authentication with a self signed certificate, I went through the following steps:  openssl genrsa -out ca.key 4096 openssl req -new -x509 -days 3650 -nodes -key ca.key -out ca.crt   Create the Server Key, CSR, and Certificate  openssl genrsa -out server.key 1024 openssl req -nodes -new -key server.key -out server.csr   We're self signing our own server cert here.  This is a no-no in production.  openssl x509 -req -days 3650 -in server.csr -CA ca.crt -CAkey ca.key -set_serial 01 -out server.crt   Create the Client Key and CSR  openssl genrsa -out client.key 1024 openssl req -new -nodes -key client.key -out client.csr   Sign the client certificate with our CA cert.  Unlike signing our own server cert, this is what we want to do.  openssl x509 -req -days 3650 -in client.csr -CA ca.crt -CAkey ca.key -set_serial 01 -out client.crt   Then I verified the created the certificates via:  Verify Server Certificate  openssl verify -purpose sslserver -CAfile ca.crt server.crt   Verify Client Certificate  openssl verify -purpose sslclient -CAfile ca.crt client.crt   which all are OK.  I configured my python tornado server:  if __name__ == "__main__":    app = make_app()     ssl_ctx = ssl.create_default_context(ssl.Purpose.CLIENT_AUTH)    ssl_ctx.load_cert_chain("../server.crt", "../server.key")    ssl_ctx.load_verify_locations("../ca.crt")    ssl_ctx.verify_mode = ssl.CERT_REQUIRED    http_server = tornado.httpserver\     .HTTPServer(app, ssl_options=ssl_ctx)    http_server = tornado.httpserver.HTTPServer(app)    http_server.listen(80)    logging.info("Server is running.")    tornado.ioloop.IOLoop.current().start()   but when I make a curl request via  curl -v -s -k --key client.key --cert client.crt https://localhost/open/address/health   It returns connection refused  *   Trying ::1... * TCP_NODELAY set * Connection failed * connect to ::1 port 443 failed: Connection refused *   Trying 127.0.0.1... * TCP_NODELAY set * Connection failed * connect to 127.0.0.1 port 443 failed: Connection refused * Failed to connect to localhost port 443: Connection refused * Closing connection 0

This is a  about Connection Refused    We see a lot of questions to the effect      When I try to connect to a system I get a message      Connection refused      Why is this ?


I'm attempting to check the next item in the array's sub-items for matching values of only some of the sub-items, then delete found matches.   I'll eventually need to add code before the deletion which will collect the difference between sub-items if a match is found so I can't simply use array_unique().   The following works to an extent;   $n = 1;  for ($i = 0; $i < count($array); $i++) {     if($array[$i]['author'] == $array[$n]['author']     && $array[$i]['parentID'] == $array[$n]['parentID']) {         unset($array[$n]);         //skip the removed item and continue;         $i++;         $n++;     }     $n++;  }   However, it only removes one instance and leaves any matching following conditions. (1 removed below, but 2 not removed)  [0] => Array     (         [parentID] => 85560         [author] => Carla         [revisions] => 1     ) [2] => Array     (         [parentID] => 85560         [author] => Carla         [revisions] => 2     ) [3] => Array     (         [parentID] => 85560         [author] => Charlie         [revisions] => 4     )   Here is the initial input;  [0] => Array     (         [parentID] => 85560         [author] => Carla         [revisions] => 1     ) [1] => Array     (         [parentID] => 85560         [author] => Carla         [revisions] => 2     ) [2] => Array     (         [parentID] => 85560         [author] => Carla         [revisions] => 2     ) [3] => Array     (         [parentID] => 85560         [author] => Charlie         [revisions] => 4     )

How can I remove duplicate values from a multi-dimensional array in PHP?  Example array:  Array (     [0] => Array     (         [0] => abc         [1] => def     )      [1] => Array     (         [0] => ghi         [1] => jkl     )      [2] => Array     (         [0] => mno         [1] => pql     )      [3] => Array     (         [0] => abc         [1] => def     )      [4] => Array     (         [0] => ghi         [1] => jkl     )      [5] => Array     (         [0] => mno         [1] => pql     )  )


Red and white little insects appeared in the flour.Are these harmful for flour? How can I save flour from those?

Sometimes I feel that little white insects seem in flour and semolina , specially in rainy season. The flour and semolina attacked  these insects can be used ? If yes then how can I remove these insects from flour and semolina ?


I have a Ubuntu desktop. I want to protect my installation from software which can steal passwords I enter by logging keystokes or capturing the screen in case of a graphical on screen keyboard. I am following the following steps:  1) Making sure I only install new software using the 'apt' command.  2) Enabling the ufw firewall to block incoming.  Are these steps enough? Can I be assured that there is no keylogger or screen capture software on my system? Or do I need to take additional precautions?

So this keylogger is being sold on HF doesn't rely on any dependencies or anything like that so it's able to infect linux systems.  Thread link:   If you are not registered with the forum here is the sales thread image:   Link is safe to view it's just a sales page on the forum.  What can I do to prevent such things infecting my system?  I read this:   I just want to confirm it's true the way it would have to install to infect me.


I am trying to markup certain words in my text and automatically commit them to the index, with the option to modify the index entry. The \newcommand approach was not satisfying, as I did not manage to set the default value of the first argument to be the second. With \NewDocumentCommand I managed to set the options properly, but it introduced an unwanted space when followed by punctuation. Can anyone explain, why this occurs and how to fix it? Here is a minimal working example: \documentclass{article} \usepackage{xparse}     \newcommand{\neuold}[2][]{{\sffamily\textbf{ #2}}\index{#1 #2}}  \NewDocumentCommand{\neu}{m O{#1}} { \IfNoValueTF{#2} {{\sffamily\textbf{#1}}} {\sffamily\textbf{ #1}\index{ #2}} }  \begin{document} blabla  \neu{test}, blabla \neuold{test}, blabla \end{document}

I see that the code in many packages and examples contains percent signs % at the end of (many) lines. What are they used for? Do they affect the parsing of those lines?


I try to write something like:  \[ \bigcup_{\gamma<\omega*2}\mathcal{T}_{\gamma}|_{\aleph _0} \]   But it can not display $\gamma<\omega*2$ underneath \bigcup in TeXstudio. What is the problem?  Here is the whole file in TeXstudio.   \documentclass[preview,border=3pt,3pt]{standalone}  \usepackage{tikz} \usetikzlibrary{shapes,backgrounds} \usetikzlibrary{calc} \usetikzlibrary{decorations.shapes} \usetikzlibrary{arrows.meta} \tikzset{decorate sep/.style 2 args=     {decorate,decoration={shape backgrounds,shape=circle,shape size=#1,shape sep=#2}}} \tikzset{>={Latex[width=1.5mm,length=3mm]}}  \begin{document}     \begin{tikzpicture}     \tikzstyle{line} = [fill=white, line width=.3pt]     \tikzstyle{gray1} = [fill=gray!5,fill opacity=0.5]     \tikzstyle{gray2} = [fill=gray!20,fill opacity=0.5]     \tikzstyle{blue1} = [fill=blue!10,fill opacity=0.5]     \tikzstyle{blue2} = [fill=blue!20,fill opacity=0.5]       \filldraw[gray2](0, 9)--(-1.67,6.5)--(-1.33,4)--(5.33,4)--(7,9);        \filldraw[blue1](-3, 9)--(-1.33,4)--(-2,9);        \filldraw[blue2](-2, 9)--(-1.67,6.5)--(0,9);             \node[above] at (-1.2,8.3) {$\bigcup_{\gamma<\omega*2}\mathcal{T}_{\gamma}|_{\aleph _{0}}$};      \end{tikzpicture} \end{document}

I'm very familiar with how symbols display differently in inline mode (with $ ... $) vs. how display math shows them (with \[ ... \] or $$ ... $$).  Two examples would be with limits  $\lim_{n\rightarrow \infty}f(x)$   vs.  \[ \lim_{n\rightarrow \infty}f(x) \]   and with sums  $\sum_{n=1}^{x} n^2$   vs.  \[ \sum_{n=1}^{x} n^2 \]   My Question is:     How do you display these things in inline mode (with all the nice inline formatting) as if they were in display mode ?   The inverse -- how to display things in display mode as if they were in inline mode -- is also of interest.


I upgraded MySql workbench to version 8. I'm running MySql Server 5.7. When I open the options file in workbench it says it cannot locate a file for MySql 8 and that it will create one in the path C:\ProgramData\MySql\MySql Server 8\my.ini I do not have MySql Server 8 installed.  Why is workbench not finding the file? How can I point it towards the correct file? Do I need to downgrade workbench?

MySQL newbie here.  I'm using Ubuntu 16.04 (64-bit). I've successfully installed MySQL Community Server 5.7 and MySQL Community Workbench 6.3.  Unable to find these answers in the MySQL forums. I've asked this on Stack Exchange and it was suggested that I ask here instead. I've searched on Ubuntu Forum and here also but did not find an answer. One would think they are common questions but maybe not. Additionally, I cannot find a way to ask a new question on the MySQL Forum. I've spent a ton of time reading/researching/installing/uninstalling and reinstalling MySQL and community workbench on Linux Ubuntu 16.04 (64-bit) and do not want to lose the momentum I've gained. I'm actually making forward progress after a week or so of trial and error working on this up to a few hours per day. It appears that I cannot load MySQL Community Workbench 8.0 without Linux server installed. That seems to be one of the requirements if I understood correctly.  Can anyone tell me if MySQL Community Workbench 6.3 will work with MySQL Community Server 8.0 on Ubuntu 16.04 (64-bit)? I would still like to upgrade and use MySQL community server 8.0 if I can.  Can I use MySQL Community Server 8.0 on Linux Ubuntu 16.04 32-bit?   I've spent many hours googling it and looking on MySQL Forums but couldn't find the answer. Thanks much. ...Rick