I want to understand why the output is 111-2-666 in detail
Is Java "pass-by-reference" or "pass-by-value"?
How to understand degrees of freedom? From , there are three interpretations of the degrees of freedom of a statistic:     In statistics, the number of degrees of freedom is the number of   values in the final calculation of a statistic that are free to vary.      Estimates of statistical parameters can be based upon different   amounts of information or data. The number of independent pieces of   information that go into the estimate of a parameter is called the   degrees of freedom (df). In general, the degrees of freedom of an   estimate of a parameter is equal to the number of independent scores   that go into the estimate minus the number of parameters used as   intermediate steps in the estimation of the parameter itself (which,   in sample variance, is one, since the sample mean is the only   intermediate step).      Mathematically, degrees of freedom is the dimension of the domain of a   random vector, or essentially the number of 'free' components: how   many components need to be known before the vector is fully   determined.   The bold words are what I don't quite understand. If possible, some mathematical formulations will help clarify the concept.  Also do the three interpretations agree with each other? Reading through this doc:      We replaced the rich text editor in HTML Area home page components   with a new version that supports more markup but doesn’t allow HTML to   be manually entered.      In Summer ’15 we will start removing unsupported code from HTML Area   home page components. As a result, components that contain JavaScript,   CSS, iframes, or other unsupported markup might stop working properly.   To use JavaScript or other advanced HTML elements in your home page   component, we recommend that you use a Visualforce Area component   instead.   With Visualforce homepage component the best we could do is design fancy home page components, which has not been the big use of sidebar amongst developers. How do we do the fancy hack we do today using html components since visualforce is hosted in a different domain will the sidebar hacks even work after summer 15?     You can include JavaScript in your Visualforce page, but because the   component is rendered in an iframe on the home page layout, the   JavaScript can’t interact with the page that contains the component.   Finally why this move :(? How to prove that there are finitely many $n$ such that $f(1+1/n) = \frac{1}{n+1}$? Let $f : \mathbb{C} \to \mathbb{C}$ be analytical. How does one prove that there are finitely many positive $n$ such that $f(1+1/n) = \frac{1}{n+1}$ ? A hint is given: think of the expression $\frac{z-1}{z}$.  I think this is a pretty hard homework assignment. Here's what I tried so far: Let $g(z) = \frac{z-1}{z} $ . Then $g(1 + 1/n) = \frac{1 + 1/n - 1}{ 1 + 1/n} = \frac{1/n}{1+1/n} = \frac{1}{n+1} $. So the given hint is probably indeed useful, but I'm not sure yet how.   Another thing I tried to use to obtain the solution was the given fact that $f$ is analytical. Let $f = g$. Then $f(z) = f(x+iy) = \frac{ x + iy - 1}{x+iy} = \frac{x+iy-1}{x+iy} \cdot \frac{x-iy}{x-iy} = \frac{x^2 - 2 i x y + y^2 + iy}{x^2 + y^2} = 1 + i \frac{y(1-2x)}{x^2 + y^2} $ . Now I have written $f$ in the form $ f = u + i v$, with $u,v$ being real-valued functions. So now we can use the Cauchy-Riemann Integral formulas: $ \frac{d}{dx} 1 = 0 = \frac{d}{dy} \frac{ y(1-2x) }{x^2+y^2} \implies \frac{y(1-2x)}{x^2+y^2} = c $. The other formula yields a similar result.   But now what? I still have no idea how to prove that there are finitely many positive $n$ such that the aforementioned equality holds. Should I use any of the results I already obtained? If so, how? If not, do you know how to prove this? Format string dynamically We're building a feature for a website and trying to think of a hypernym for clients, partners and members so that the feature remains generic enough for re-use later on other websites. What can I do if a repository/PPA does not have a Release file? Why is the installer not showing any partitions? I'm having a problem installing Ubuntu, and Kali as well. I downloaded the iso from the official site &amp; tried installing using USB. I also tried desktop installation, but the problem is same.  It shows a single drive i.e. my total Hard Disk and if I select it, it asks me to create a new partition &amp; shows total space as FREE.  It's with all Ubuntu I downloaded, 11.10 Server, 12.10 and 13.04. I also tried to install BackTrack's new version Kali Linux but again I got the same problem.  I hope I meet thier system requirements. Here's my system details for your ease:   OS: Windows 7 Ultimate Processor: Intel P4 2.80 GHz RAM: 3GB Hard Disk: 320GB No of Local Drives: 4 (1 Primary, 3 Logical) Free Space: 195GB (about) Motherboard: G31 Cache: 1MB Help me, please. I have a realy strange problem in Ubuntu 11.10. I have by accident my password set to empty. If I wan't to install software now the system asks for a password, but I haven't one anymore. If I enter my old password it sais it's wrong and if I leave it empty it also does. Now I wan't to set my password back, but the system asks for the old password before I can change it. That password doesn't exist, so I can't do anything anymore! Can someone help me please? User suggested great corrective edit to my answer, but the edit was rejected. What can I do to approve it? I made a series of outdoor shots with Nikon D5000, with the 18-55mm 1:3.5-5.6G VR kit lens.  On some shots, I see in the EXIF info f/11, and in another shot, f/9.    How can that be, that the f-number is greater than 5.6, when that's listed as the maximum in the lens spec? I had recently entered the UK without a visa to be with my partner, from 21 July 2016 until 16 December 2016. I hope to return on the 9th of January. We don't meet the income requirement for a Spouse visa. I recently applied to university, and got in, and was intending to return to the UK on a student visa, but my university did not tell me about maintenance fees and my loan wasn't large enough to cover it all, so my visa would have been denied.  Now, I am hoping to attend university in the next semester, and therefore return to the US to apply for that visa. Do you think that if I try to return to the UK without a visa, I will be turned away?  I won't be working or studying during this time, however, I'm afraid that they'll consider it living in the UK illegally; I don't have a criminal record or anything like that. Space after LaTeX commands My hypothesis is that $\mathbb{R \times R}$,  the set of all pairs $(r_1, r_2)$, of real numbers is uncountable. I understand that the set of all pairs of natural numbers is countable. But could someone explain why the set of all pairs of real numbers uncountable? I am having trouble proving it using diagolization Is there a theorem that says that QFT reduces to QM in a suitable limit? Of course, it should be, as QFT is relativisitc quantum mechanics. But, is there a more manifest one? such as Ehrenfest's theorem which dictates the transition from QM to Classical Mechanics.  I am curious as the basic object in QM is wave function whereas the basic object in QFT is quantized operator, which looks very different, and wondering how the comparison works.  (Of course, I am aware that QFT can calculate corrections for Coulomb potential energy, which may seem to be a transition from QFT to QM, but I want one more manifest than that.) Number of reflexive relations defined on a set A with n elements Associates in Integral Domain Let $x$ and $y$ be nonzero elements of an integral domain $D$. Then $x$ and $y$ are associates if and only if $x = yd$ for some unit $d \in D$.    I am done proving the $\Leftarrow$ part. For $\Rightarrow$ what I did was: If $x$ and $y$ are associates then $x \mid y$ and $y \mid x$, so $x \mid y$ implies that $xs = y$ for some $s \in D$ and $y \mid x$ implies that $yt = x$ for some $t \in D$. That is, $yts=y$ which implies $ts=1$. Therefore $s$ is a unit and $t$ is a unit.    Am I on the right track? Can I say that the proof is complete? How to disable "time travel" entirely? Watch Filesystem in Real Time on OS X and Ubuntu I'm looking for a CLI tool which will watch a directory and spit out the names of files that change in real time.   some_watch_command /path/to/some/folder | xargs some_callback   I'm aware of inotify (inotify-tools?) and it seems to be what I need, but I need something that is both Linux (in my case Ubuntu) and OSX compatible.  It doesn't need to be lightning fast, but it does need to trigger upon changes (within a second is reasonable). Also, I don't necessarily need the exact CLI program mentioned above.  If some underlying tech exists and is easily scriptable on both platforms that would be great too. How to check that a cubic polynomial is irreducible? Why does a cordless circular saw have the blade on the left? At the moment considering the purchase of a circular saw for light work. I'm looking at a corded model and a cordless model. But the question I have is not about which one is better.   My question today is why the corded one has the blade on the right of my hand and the cordless one has the blade on the left of my hand. See both models below.     Now, I know some manufacturers make left- and right-handed versions of their circular saw. And I'm also aware that 'worm drive circular saws' usually have the blade to the left of my hand. But it seems odd to me. Especially as it seems to apply to most manufacturers too.   Was wondering if somebody has an explanation for this.