I'm a newbie :)   My context: I installed Ubuntu in a desktop behind a proxy that needs authentication, its very very boring because I need to configure proxy's URL, and to enter my username and password in everything, example: firefox, eclipse, and etc...   I need something to leave it in a transparent way(for programs, it would be as if they are in a direct connection)  There is a natively way (or third-party program) that allows to storage my proxy authentication(preferably, encrypted), and Ubuntu ALWAYS use this information to ALL System and software?
How do you configure proxy settings in the Ubuntu Server or Minimal (CLI) versions using the terminal?
Why does aptitude give me intel-microcode upgrades when I have an AMD processor? I have a Supermicro AS-2022G-URF (H8DGU motherboard) with 2 AMD Opteron 6272 16C/16T 2.1GHz and an LSI MegaRAID SAS 2108 RAID controller currently running Ubuntu Server 14.04 LTS (scheduled to be upgraded to 16.04 this summer). Several times over the last year, when I have done aptitude update/upgrade, the intel-microcode package has shown up as one of the packages that will be installed. Since this server has AMD processors, not Intel, Why does aptitude offer this package? Is it in any way necessary for other reasons? Any ill effects from going along with aptitude on this? Why bosons have integer spin and fermions have half-integer ones? Due the fact that the fermions are the "block particles" and the bosons are the "carriers" I just came out with the question that, why the "block particle" have half-integer spin and the "carriers" have an integer spin? Black screen after suspend-after moving to the nvidia official drivers (not priority) So, when I used the priority drivers, the suspend worked normal. But the official drivers works better, so I installed the official driver. Then suspend won't work.  Should I change any text/documants to make it work? Any solution will be aprreciated, thanks you all! What's the past participle form of the word exit? Is it exit (irregular, like set)? exited? exitted? On one page I found exited but if that's the case why isn't it exitted (double t) like with the word emit - emitted? Is there a rule when the consonant at the end is doubled and when not? How to add features to a PostGIS layer using Quantum GIS? I am using Quantum GIS and the PostGIS dbms. I am able to call the PostGIS layer into QGIS but i am unable to add feature to it. I am using the method of adding features to a Shapefile but still it is not getting reflected in the layer, and I don't know how to save it to the PostGIS database if I am able to add the feature to the PostGIS layer.  I may not have used some technical term for this problem because i don't know what to call it, I am expressing the problem in my own terms. How can I straighten ALL the vertical UV lines at once? Is there a hot keyshort cut? Or if I have to do them one by one .. is there at shortcut for that? Thank you! What is difference between have/get/make someone do something? Find the number of natural solutions of $5^x+7^x+11^x=6^x+8^x+9^x$   It's easy to see that $x=0$ and $x=1$ are solutions but are these the only one? How do I demonstrate that?  I've tried to write them either:  $$5^x+7^x+11^x=2^x*3^x+2^{3x}+3^{2x}$$  or  $$5^x+7^x+11^x=(5+1)^x+(7+1)^x+(11-2)^x$$  and tried to think of some AM-GM mean inequality or to divide everything by $11^x$, but those don't seem like the way to go. Any hints? Difference Between Sequential Workflow & State machine workflow? What is the difference between Sequential Workflow and Stater machine workflow? What context should I take account to when choosing one of them? Induction Proof: Fibonacci Numbers Identity with Sum of Two Squares Kali Linux: apt update returns "Hash Sum mismatch" error I'm experiencing exactly the same issue as described in this question: . Before you mark this as a duplicate however, I have tried the solutions posted there, as well as on numerous other sites, including:  sudo apt-get clean sudo rm -rf /var/lib/apt/lists/* sudo apt-get update   Editing /etc/apt/sources.list with alternate official mirrors, such as  deb http://mirrors.ocf.berkeley.edu/kali kali-rolling main non-free contrib or deb https://http.kali.org/kali kali-rolling main non-free contrib  Everything worked after I first imported the VM. I ran sudo apt update and it found some ~650 packages to upgrade. I ran sudo apt upgrade and it encountered an error partway through. That error was solved using sudo apt --fix-broken install, but that is when this hash sum error began. Unfortunately due to hours of troubleshooting I no longer have the details of the earlier error, but I believe it was an error extracting a package due to corrupt data.  I've tried multiple official mirrors, but I get the same error. Additionally, when I downloaded the Packages.gz file  on my Windows machine (VM host) and computed the SHA256 hash, I got the exact hash that apt printed as the expected value. This led me to believe that the error was not with the mirror but with my VM.  The next thing I tried was wget https://mirrors.ocf.berkeley.edu/kali/dists/kali-rolling/main/binary-amd64/Packages.gz followed by sha256sum Packages.gz, which provided yet another different hash output.  To be clear, I have seen 3 different hashes for the same file:   The "correct" hash shown by apt as expected, which is the one that windows also produced after downloading the file using a browser The incorrect hash calculated by apt, which led to the error A different hash calculated by sha256sum after downloading the file using wget using the same URL as for the browser download   I should also note that I have only been referencing the SHA256 hash in each step. The other hash functions are also mismatched when I run sudo apt update, but the file size is the same. I had considered that downloads might be failing due to limited disk space (it is a VM after all) but I don't think that's the case.  What am I missing? My desktop look is empty so all I have is a nice wallpaper. My Windows taskbar has the "Taskbar Appearance" setting to "Auto-hide the taskbar". Although hidden, it leaves a thin top layer so you can still see it a bit, and where the pinned shortcuts are. Is it possible to totally have it hidden without a trace? This is a serious question. It really bugs m. If we have two circles in the plane described by $(x_1, y_1, r_1)$ and $(x_2, y_2, r_2)$ we can determine if they are completely disjoint by simply:  $$(x_1 - x_2)^2 + (y_1 - y_2)^2 &lt; (r_1 + r_2)^2$$  Assume this is not the case, we now want to know if one completely overlaps the other.  (That is: if the second circles interior is a subset of the first circles interior.)  If $(x_1, y_1) = (x_2, y_2)$ than we can trivially compare radii, so lets assume their centers are distinct.  The way I have imagined is to create a parametric equation of the line that connects the two centers:  \begin{align} x_p(t) &amp;= x_1 + t(x_2 - x_1) \\ y_p(t) &amp;= y_1 + t(y_2 - y_1) \end{align}  Then we calculate the two line segments (represented as two pairs of t values) where the circles intersect this line.  One is a subset of the other if and only if the corresponding circles are subsets of each other.  Is there a simpler approach I am overlooking? Problem with finding the GCD in the Field of Polynomials mod p I am really having trouble working a problem in my course. I will post it and then add what I have thought etc.  Let p be an odd prime, then using the Euclidian Algorithm, calculated the GCD of of $x^{p-1}-1$ and $x^2+1$ in $\mathbb{Z} / p\mathbb{Z}[x]$  Also, how does $p=1 (mod4)$ tell us that  $-1$ is a square in $\mathbb{Z} / p\mathbb{Z}$, infact that $-1$ is a square here if and only if $p=1(mod4)$.  My thoughts:   I know that $$x^{p}-x=(x)(x-1)(x-2)…(x-(p-1))$$ and so that in this sense our roots will be the congruence classes of $1,2,…p-1$  and also that $$x^{p-1}-1=(x-1)(x-2)…(x-(p-1))$$  But I get lost when trying to apply the EA to these polynomials,  like how can I do it when p is arbitrary?  Preferably id like to be able to understand/see how to do the first part first i.e. using division with residue and then move on to the second part. Any insight/hint or solution to this would be great,  Thank you all  Update:  When I try to do division with residue, I just get  $$x^{p-1}-1=(x^2+1)(x^{p-3}-x^{p-5}+x^{p-7}-x^{p-9}...)$$  for example,  $p=7$  $$(x^{6}-1)=(x^2+1)(x^4-x^2+1)$$  for $p=11$  $$(x^{10}-1)=(x^2+1)(x^{8}-x^{6}+x^{4}-x^{2}+1)$$  which for specific cases tells me that 1 is the gcd, but I dont know how to generalize that for the case with arbitrary prime p. Could someone make the proof into a hinted exercise? Let $(c_n)$ be a sequence of positive numbers.  Could someone make the proof of the inequality  $\displaystyle\limsup_{n\to\infty}\sqrt[n]{c_n}\leq\limsup_{n\to\infty}\frac{c_{n+1}}{c_n}$  into a hinted exercise? Database schema documentation for the public data dump and SEDE Stack Exchange releases "data dumps" of all its publicly available content roughly every three months , and also makes that information queryable over the Internet at the  (SEDE) (updated weekly, on Sunday). Over time, as new features and other bits of data are introduced to Stack Exchange sites, the "anatomy" of the data dump is likely to change. Difference between Inheritance and Composition Which statistical test to analyse? I am trying to find out how inflammatory markers change in response to a mechanical device change. I have daily readings for the 5 days before the event and for the 5 days after the event. I am expecting a rise in inflammatory markers in the pre readings followed by a fall after the device change. I also need to find out how the change differs in two subgroups (sample sizes of the subgroups are n=21 and n=88). The aim is to find out if the change is significant, to consider these markers as predictors of the device failing and hence needing to be changed.    I would like to know what test would be appropriate to analyse this. I need to keep things simple as I and the people reading the results are non-statisticians. This has been nagging me for a while and then I saw  asking what the difference is between variables and parameters. In the context of mathematics, what is the difference between  variables constants parameters arguments  I get 1. and 2. confused because, for example the general form of the quadratic function is often expressed $f(x)=ax^2+bx+c, a \neq 0$ and $x$ is the variable so what does that make a,b and c? I assume since math is so rigorous with precise definitions, these have one, but it is also a valid answer that as words they do not have a single precise definition. Introduction to proofs with a fair amount of hand-holding?