A. Do you have a car?   Or     B. Have you a car?   I always use the first form of the sentence but I noticed that the second one is also used. Which is correct?
Is the following sentence correct English?      Have you the address?   The address in question is obvious to the person being asked.  It's normal to ask such a question as "Do you have the address?" or even "Have you got the address?" But is it acceptable to use just the verb have without do or got?
How prove this $\prod_{1\le i<j\le n}\frac{a_{j}-a_{i}}{j-i}$ is integer Is there a way to xcopy just changed or new files? I am trying to deploy a website from my desktop to my webserver and so right now I am doing this:   xcopy C:\source X:\destination /s   My desktop is a Windows XP machine, and I need to copy to a Windows Server 2008 machine, but this copies everything and the whole site is very large and it takes a really long time to finish copying.   Is there a way to specifically just copy new or updated files? I see you can pass in a changed-since date, but I wanted to see if there is a simpler way to compare against the destination file...  Also, I am open to using anything outside of xcopy that can do the job as well... More section headings? I am a novice in LaTeX and I have one question.  Can someone tell me what if you want more heading's in LaTeX. Like 5 or 10 or even 15. Is there a package for that? Note: This question was asked at a time when C# did not yet support optional parameters (i.e. before C# 4).  We're building a web API that's programmatically generated from a C# class. The class has method GetFooBar(int a, int b) and the API has a method GetFooBar taking query params like &amp;a=foo &amp;b=bar.   The classes needs to support optional parameters, which isn't supported in C# the language. What's the best approach? Moving here does not mean moving to a new city or something like that. I am talking about the people that just can't stay at one place. It is impossible for them to sit put at one place and relax. Are $(\mathbb{R},+)$ and $(\mathbb{C},+)$ isomorphic as additive groups?  I know that there is a bijection between $\mathbb{R}$  and $\mathbb{C}$, and  asks whether they are isomorphic as abelian groups, are they referring to the additive abelian group? If so is there any simple isomorphism I can find? I know nothing about Hamel basis. Thanks. I found a feature request at  but it doesn't seem easy to get a column view with Nautilus while with Mac OS X it's a default feature.  Have I missed something or is this not currently possible? If $\gcd(a,b)=1$, $\gcd(a,y)=1$ and $\gcd(b,x)=1$ then prove that $ax+by$ is prime to $ab$ If $\gcd(a,b)=1$, $\gcd(a,y)=1$ and $\gcd(b,x)=1$ then prove that $ax+by$ is prime to $ab$.  I tried assuming Diophantine Equations for all the relations and representing everything in terms of $a$, but that didn't lead me anywhere. There must be an intuitive and elegant approach right? I have a statement,     Either p or q   and I have to write it in terms of logical connectives but I don't get which logical connector should I be using? Here is what I did (I think there could have been a better way to do this)     $(p \lor q ) \land (\neg((p \Rightarrow q) \land (q \Rightarrow p)))$ Upon system restart, dconf editor doesn't save changes I can use the dconf-editor to change my touchpad settings to natural scrolling, but upon system restart the settings get reverted. (But not on sleep or hibernate.) When I open the editor, the option is still orange indicating it has been changed. when I uncheck and recheck the natural scroll option, it is re-enabled. Is there a fix, or am I changing the wrong option? The path is org > gnome > settings-daemon > peripherals > touchpad > natural-scroll.  Currently running 13.10 Probability of student passing an exam There're $25$ tests, each with $2$ questions. There're total of $50$ different questions (the questions do not repeat). The student knows the answer of $44$ questions. To pass the exam, the student needs to correctly answer both questions on the first test he drew, or answer $1$ question from the test he drew first, and $1$ question from the test he drew second. (meaning he draws twice if he answers a question incorrectly on his first try)  What is the probability that the student will pass the exam?  I have never faced a problem like this one so any help is appreciated. I was thinking about approaching it "manually" with some applied combinatorics but I feel like there's a much easier way that I am not familiar with. How can I break on an unhandled exception in ASP.NET? Prove the $n$th Fibonacci number is the integer closest to $\frac{1}{\sqrt{5}}\left( \frac{1 + \sqrt{5}}{2} \right)^n$ Prove that the $n$th Fibonacci number $f_n$ is the integer that is closest to the number $$\frac{1}{\sqrt{5}}\left( \frac{1 + \sqrt{5}}{2} \right)^n.$$   Hi everyone, I don't really understand the problem. I have the following hint, but I don't know how to work it.     Hint: Show that the absolute value of $\frac{1}{\sqrt{5}}\left( \frac{1 - \sqrt{5}}{2} \right)^n$ is less than $1/2$. What is the difference between linear regression and logistic regression? Does each imply the other? If not, does one imply the other? Why/why not?  This issue came up in response to a comment on an answer I posted .  Although google searching the relevant terms didn't produce anything that seemed particularly useful, I did notice  on the math stackexchange. However, I thought that this question was appropriate for this site too.  EDIT after reading the comments  Relative to the math.stackexchange answer I was after something more in depth, covering some of the issues dealt with in . Also, as I see it the math.stackexchange question shows that consistency doesn't imply asymptotically unbiasedness but doesn't explain much if anything about why. The OP there also takes for granted that asymptotic unbiasedness doesn't imply consistency, and thus the sole answerer so far doesn't address why this is. Recursive function, if and which statements Why are Bitmap-Fonts used automatically? I have the following LaTeX-document:  \documentclass[a4paper,11pt]{article} \usepackage[utf8x]{inputenc} \usepackage[ngerman]{babel}  \usepackage[T1]{fontenc}  \title{Sample} \author{Litb}  \begin{document}  \maketitle  \begin{abstract}  This is a report about my praxis phase at the company foo bar which I enjoyed. \end{abstract}  \end{document}   Much to my frustration, compiling with pdflatex creates a document with Bitmap-fonts. The reader's font-list shows that it uses Type3 fonts.  If I remove the fontenc loading, then I get a PDF using vector-fonts, but I heard that I should keep it, for having native German Umlauts working.  Does anyone know how I can get vector fonts with T1, and why it keeps using bitmap fonts if I have that package-load line in it? Contraction of Kronecker delta = 4 This suggests, as a shortcut notation, the concept of lowering indices; from any vector we can construct a (0, 1) tensor defined by contraction with the metric: $$A_\nu ≡ g_{\mu\nu}A^\mu$$  so that the dot product becomes $$g_{\mu\nu}A^\mu B^\nu = A_\nu B^\nu$$  We also define the inverse metric $g^{\mu\nu}$ as the matrix inverse of the metric tensor: $$g^{\mu\nu}g_{\nu\rho} = δ^\mu_\rho$$  where $δ^\mu_\rho$ is the (spacetime) Kronecker delta. (Convince yourself that this expression really does correspond to matrix multiplication.) Then we have the ability to raise indices: $$A^\mu = g^{\mu\nu}A_\nu$$ Note that raising an index on the metric yields the Kronecker delta, so we have $$g^{\mu\nu}g_{\mu\nu} = δ^\mu_\mu = 4$$  I don't understand why $δ^\mu_\mu = 4$. Shouldn't it equal 1? Another question I am struggling with:  Let $f:\mathbb{R} \rightarrow \mathbb{R}$ be defined in a neighborhood of $a$ (except maybe $a$ itself) and suppose that, $\lim_{x \rightarrow a}\left(f(x)+\dfrac{1}{\left|f(x)\right|}\right)=0$. Find $\lim_{x \rightarrow a}f(x)$, and prove by definition, that this is indeed the limit.    Thank you all for your answers!!  But.. How can I prove by definition that this is indeed the limit? take $\epsilon&gt;0$, I have to show that there exists a $\delta&gt;0$ such that, $|x-a| \leq \delta$ implies $|f(x)+1| \leq \epsilon$. now, I do know that there exists an $\delta_1&gt;0$, such that $|f(x)+\frac{1}{|f(x)|}|&lt; \epsilon$.Or, $\frac{\epsilon}{k}$ for some constant $k$ But, how can I continue from there? This is a  about Fighting Spam.   Also related:                    There are so many techniques and so much to know about fighting SPAM. What widely used techniques and technologies are available to Administrator, Domain Owners, and End Users to help keep the junk out of our inboxes?  We're looking for an answer that covers different tech from various angles. The accepted answer should include a variety of technologies (eg SPF/SenderID, DomainKeys/DKIM, Graylisting, DNS RBLs, Reputation Services, Filtering Software [SpamAssassin, etc]); best practices (eg mail on Port 25 should never be allowed to relay, Port 587 should be used; etc), terminology (eg, Open Relay, Backscatter, MSA/MTA/MUA, Spam/Ham), and possibly other techniques.