I'm trying to install win 7 on dell xps laptop. I burned the win7 on my 16 gb flash with no issues. When installing windows ,"no device drivers were found" error appears. I installed the drivers, and copied to usb, but it is not appearing in "Browse" OPTION, it shows only :   c: RECOVERY D: LOCAK DISK E: CD DRIVE X: BOOT   So my Question is : Why usbs are not appearing so I can select the drivers to be downloaded?
I have an Asus R500VD laptop which came with the preinstalled Windows 8. As actually this computer will be used by my grandmother (and she's only using win 7) I'd like to downgrade it.  Thanks to other thread here, I was able to successfully boot computer from Windows 7 USB stick, but unfortunately during install I got a message:  A required CD/DVD drive device driver is missing. (...)   and I can't get pass it... This is what I've done:   I've downloaded all drivers from Asus Website (), unzip and copied to visible location for windows 7 installation - I've picked each one of them, none has helped. As I belive it's some kind of problem with SATA/RAID/AHCI drivers I went to Intel site and downloaded various "Intel Rapid Storage Technology" drivers - a lot of them were recognized by win7, but none of them helped.   Does anyone have an idea what can I do next? Any help would be really appreciated.
Square version of \cdot (small black square)? I'm looking for the symbol that's similar to \cdot in math mode, but instead of a small circle, it's a square. Like this: Agreement With Compound Subjects Joined by And I was surfing the internet the other day when I found this phrase: Instead your precious time and attention is wasted. To my ears, it sounds wrong. But I'm not a native English speaker, so I consulted with a number of them, and some of them said that it was "is" because the adjective modifies only the noun "time" and not "attention". Others said it "is" because that's just how it is. But I still believe it should be "are". Any help is appreciated. Can a character use the Misty Step spell to escape from the Iron Bands of Bilarro? Can a character escape the  (DMG p. 177, listed in the SRD as the ) with the  spell? To clarify, I am not asking if the bands prevent teleportation. I am asking whether the bands are teleported with the character as he teleports using misty step. The following code gives me an error:  \documentclass[12pt]{article} \usepackage[margin=2cm]{geometry} \usepackage [english]{babel} \usepackage{amsmath, amssymb} \usepackage{enumitem, array} \begin{document} {\begin{minipage}[t]{\textwidth} \begin{enumerate}[label=(\roman*)] {\setlength\itemindent{10pt}\item  \begin{equation*} \begin{array}{&gt;{\centering\arraybackslash}m{1.5cm}&gt;{\centering\arraybackslash}m{1.5cm}&gt;{\centering\arraybackslash}m{1.5cm}&gt;{\centering\arraybackslash}m{1.5cm}&gt;{\centering\arraybackslash}m{1.5cm}}  \hline x &amp; l_{[x]} &amp; d_{[x]} &amp; l_{x+1} &amp; \mathring{e}_{[x]} \\ \hline \end{array} \end{equation*}} \end{enumerate} \end{minipage}} \end{document}   Note: for various reasons, I have to keep minipage there. For some reason, this code gives me an error when it compiles. It gives the following output:     The errors either say there is a } missing or a $ missing. My eyes don't see such a thing! How to find manually installed packages? I installed a plain Ubuntu 10.10 on my computer and installed some software via apt-get. Last week I managed to break everything and just started from scratch, and I need to reinstall my software. Is there some way to create a list with all the packages that I have installed manually?  So that it would give me a list like texlive, ... and not texlive, texlive-dep1, textlive-dep2, ... and all the standard packages removed?  If I could somehow figure out which programs out of the regular install I have removed, that would be awesome too!    Update 2015-05-23: I now use Ansible as configuration management on my systems. There I specify the packages to install. This serves the goal, installing all the programs on a fresh system, even better. So this question might be the entry into some light configuration management. Top angular speed of electric motor I recently came across a question asking the following:     If a motor is switched on, it quickly reaches a top speed. Why does it not just go faster and faster and faster?   I thought it might be related to the fact that the electrical power is constant, so I tried approaching with $P=\tau \cdot \omega$. However I still do not have any clue to reaching the conclusion.  Is it somehow related to the energy loss (due to friction)? Like the terminal speed of a parachute or something? But I was thinking that friction should be constant ($f=\mu \cdot N$) while air drag is related to the speed, so this may not be the answer.  Thank you. What is the tolerable magnetic field (in Tesla) for a hard disk? I was wondering what would be the safest magnetic field for a hard drive so that the data inside it is safe and not wiped off?  For example I have a 2.1 home theatre system and when I take my android phone near it to check the magnetic field range it gives me a reading of 1000 micro Tesla. Would that be considered safe for a nearby hard disk? Cannot mount NTFS partition in Ubuntu 13.04 After I installed Ubuntu 13.04, I can't mount my NTFS partition.  Error mounting /dev/sda5 at /media/mrxfly/xFLyDiskData: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sda5" "/media/mrxfly/xFLyDiskData"' exited with non-zero exit status 14: The disk contains an unclean file system (0, 0). Metadata kept in Windows cache, refused to mount. Failed to mount '/dev/sda5': Operation not permitted The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option. I was running out of space for Windows 10, so I deleted my Ubuntu partition and then combined the free space and added it to the Windows 10 partition into a single partition (the boot partition was untouched). Now all I get when I turn on my computer is:  Error no such partition. &gt;grub rescue   I have tried rebooting, but it did not work. Is there any way to fix it? My idea is that if i reinstalled Ubuntu it may fix it, but I'm not sure. I don't have a Windows repair disk, and I can't make one, but I do have a 4GB USB flash drive. I know if $\ i\ $  of the following form $\ 3x^2 + (6y-3)x - y\ $ or $\ 3x^2 + (6y-3)x + y - 1, \ \ x,y \in \mathbb{Z}^{+},i \in \mathbb Z_{\ge 0}$,  then $\ 12i + 5\ $ must be composite number, because:  $12(3x^2 + (6y-3)x + y - 1) + 5 = 36x^2 + (72y - 36)x + (12y - 7) = (6x + 12y - 7)(6x  + 1)$  How come if $\ i\ $ not of the following form $\ 3x^2 + (6y-3)x - y\ $ and $\ 3x^2 + (6y-3)x + y - 1\ $,  then $12i + 5$ must be prime? $\ x,y \in \mathbb{Z}^{+},i \in \mathbb Z_{\ge 0}$.  For example: $\ 5 = \ 3*1^2 + (6*1-3)*1 - 1\ $ ,when $\ x = y = 1\ $, as proved before,$\ 5*12+5\ $ must be composite number;  $\ 0, \ 1. \ 2.\ 3.\ 4\ $ can't of the following form $\ 3x^2 + (6y-3)x - y\ $ and $\ 3x^2 + (6y-3)x + y - 1\ $,  $\ 12*0 + 5 = 5\ $, $\ 5 $ is prime,$\ 12*1 + 5 = 17\ $, $\ 17 $ is prime, and so on, If $a_n$ goes to zero, can we find signs $s_n$ such that $\sum s_n a_n$ converges? Let $a_n$ be a sequence of complex numbers that converge to zero. Can we always find $s_n \in \{-1,1\}$ such that $\sum_{n=1}^{\infty} s_n a_n$ converges?  If the $a_n$ are real numbers, we can find such a sequence $s_n$. If the partial sum of the first $N$ terms is positive we make sure the following terms are negative until the sum becomes less than zero. Then we switch to making the terms positive until the partial sum becomes greater than zero, and so on. It is easy to see that the partial sums will either tend monotonically towards zero, or oscillate around zero with decreasing amplitude.   Edit: Actually there is no reason that the partials sums should go to zero in the monotone case. They will still converge however. How to fix Footnote position at the bottom of the page \footnote[1]{\nameref*{8.1.16} is an अधिकार सूत्र it goes upto \nameref*{8.3.55}} \&amp; अङ्गाधिकार (अङ्गस्य)\footnote[2]{\nameref*{6.4.1} is an अधिकार सूत्र it goes upto \nameref*{7.4.97}}  I am using footnote as shown above. However the footnote appears to be floating and when I don't have much in the page it appears in the middle of the page. I got by so far with \vspace{} but I think there must be a way to position this at the bottom of the page despite whats in the page. Thanks for your help Solve for $x$ in $6x^2-25x+12+\frac{25}{x}+\frac{6}{x^2}=0$ How long should I keep my tax documents, and why? Let $F$ be a field. Why does $F[x]$ have infinitely many irreducible elements?   For the case F has characteristic 0  Then x-a is irreducible for all a $\in F$ since x satisfies no non-trivial relations in F.  Obviously this argument fails for a finite field since there are only finitely many a to choose from.  So how may I construct irreducible polynomials in a finite field?  I figure it must involve higher powers of x, maybe $x^n-a$ ? Let $R$ be a sub-ring of a ring $S$. Let $f,g$ be non-zero polynomials in $R[x]$ and assume that the leading coefficient of $f$ is a unit in $R$. If $f$ divides $g$ in $S[x]$, show that $f$ divides $g$ in $R[x]$.   Thoughts: If $f$ divides $g$ in $S[x]$, then  $g(x) = f(x)q(x)$ for some $q(x)$ in $S[x]$. From here I'm not sure what the question is asking. Do I have to show that $q(x)$ is an element of $R[x]$ ? Insights appreciated. Q1. Find the general solution to the difference equation  $$ a_{n} - 4a_{n-1} + 3a_{n-2} = 6 $$    Q2. Solve the difference equation   $$ a_{n} - a_{n-1} - 2a_{n-2} = 0, a_0 = 2, a_1 = 4 $$    I am completely lost in solving recurrence relation questions. Can anyone guide me in steps to solve the following 2 questions? This is from page 3 of  ().  Copying the relevant segment:     Stirling’s approximation tells us $\sqrt{2\pi n} (n/e)^n \leq n! \leq e^{1/12n} \sqrt{2\pi n} (n/e)^n$. In particular we can use this to say that   $$ {n \choose k} \leq \left(\frac{en}{ k}\right)^k$$   I tried the tactic of combining bounds from $n!$, $k!$ and $(n-k)!$ and it didn't work. How does this bound follow from stirling's approximation? How does one account for the momentum of an absorbed photon? I am writing a small matrix library in C++ for matrix operations. However my compiler complains, where before it did not. This code was left on a shelf for 6 months and in between I upgraded my computer from debian etch to lenny (g++ (Debian 4.3.2-1.1) 4.3.2 ) however I have the same problem on a Ubuntu system with the same g++.  Here is the relevant part of my matrix class:  namespace Math {     class Matrix     {     public:          [...]          friend std::ostream&amp; operator&lt;&lt; (std::ostream&amp; stream, const Matrix&amp; matrix);     } }   And the "implementation":  using namespace Math;  std::ostream&amp; Matrix::operator &lt;&lt;(std::ostream&amp; stream, const Matrix&amp; matrix) {      [...]  }   This is the error given by the compiler:     matrix.cpp:459: error: 'std::ostream&amp;   Math::Matrix::operator&lt;&lt;(std::ostream&amp;,   const Math::Matrix&amp;)' must take   exactly one argument   I'm a bit confused by this error, but then again my C++ has gotten a bit rusty after doing lots of Java those 6 months. :-)