I am running Kubuntu 18.04 with a GTX 980. I installed NVidia driver version 396, and now the machine boots to a black screen. CTRL+ALT+F1 through F6 do not do anything at any time while the machine is booting.  How can I fix this?
I am trying to boot Ubuntu on my computer.  When I boot Ubuntu, it boots to a black screen.  How can I fix this? Table of Contents:
What does "I have got some time on my hands" mean? My shift at work's kinda long, so I've got some time on my hands to, you know...whatever. Think, I guess.   What does "I have got some time on my hands" mean in the above quote? How to compute $\lim\limits_{n\rightarrow \infty} \{(2+\sqrt{3})^{n}\}$, where $\{x\}$ is the fractional part of $x$? I've stumbled upon the following problem:  $$\lim_{n\rightarrow \infty} \{(2+\sqrt{3})^{n}\}$$  where "{}" notates the fractional part.  I've never studied this kind of problem, there exists any reference that I could read about this type of problem? Direction arrows on a circle I would like to plot circle (or another curve) with positive direction (and show it wit arrows).  This plots the circle  \documentclass{article} \usepackage{tikz} \RequirePackage{pgfplots} \usetikzlibrary{shadows} \usetikzlibrary{shapes} \usetikzlibrary{decorations} \usepackage{verbatim} \usepackage[active,tightpage]{preview} \PreviewEnvironment{tikzpicture} \setlength\PreviewBorder{5pt} \begin{document} \begin{tikzpicture}     \begin{axis}[             xmin=-1.5,xmax=2.5,ymin=-1.5,ymax=1.5,             axis lines=center,             ticks=none,             unit vector ratio*=1 1 1,            ]                   \addplot [very thick, smooth, domain=(0:2*pi)] ({1.+cos(deg(x))},{sin(deg(x))});        \addplot[only marks,mark=*] coordinates{(1,0)};         \end{axis} \end{tikzpicture} \end{document}   And I want to add arrows like that    Would you advise me how to add such arrows? Is it supposed to be a HTML or an HTML I've seen many people who say:     This is a HTML page.   Yet I've also seen many people who say:     This is an HTML page.   Are both usages equally correct?  Or, which is the grammatically correct one?       Possible Duplicates: I want to set up a diary that compiles in two different orders: One is work by day, the other is work by project according to tags I give to the particular chunks of work I did each day.   For example, I write my diary as usual in work by day form:  2/2/15  -- bought a new screwdriver (tag: car maintainence)   -- scetched my plan for world domination (tag: world domination)  3/4/15  -- started studying physics (tag: world domination)  -- finished tax declaraction (tag: burocracy)   Compiling by project would yield tags as sections:  car maintainence    -- 2/2/15: bought a new screwdriver  world domination  -- 2/2/15: scetched my plan for world domination  -- 3/4/15: started studying physics  burocracy  -- 3/4/15: finished tax declaraction   I know this is pretty close to the literal programming paradigm the whole LaTex documentation follows: A code chunks in a document can be compiled to two different orders: For human understanding and for use by the machine. However, I want two human readable versions --say pdf-files-- as output. Is there some package that helps? How put color in all math mode? what is the total number of distinct arrangements of $n$ oranges and $n$ apples around a round table? I have no idea how to go about. Proving that two matrices are congruent, in order to establish a rank and signature result. Is it touch(1) from coreutils-8.4-37.el6.x86_64 or my brain which is broken?  $ touch abc $ LANG=C stat abc   File: `abc'   Size: 0               Blocks: 0          IO Block: 4096   regular empty file Device: fd04h/64772d    Inode: 10485773    Links: 1 Access: (0664/-rw-rw-r--)  Uid: (3060399/ nodakai)   Gid: (  418/   quant) Access: 2016-10-14 18:42:06.189751847 +0800 Modify: 2016-10-14 18:42:06.189751847 +0800 Change: 2016-10-14 18:42:06.189751847 +0800 $ touch -a abc $ LANG=C stat abc   File: `abc'   Size: 0               Blocks: 0          IO Block: 4096   regular empty file Device: fd04h/64772d    Inode: 10485773    Links: 1 Access: (0664/-rw-rw-r--)  Uid: (3060399/ nodakai)   Gid: (  418/   quant) Access: 2016-10-14 18:42:17.374235446 +0800 Modify: 2016-10-14 18:42:06.189751847 +0800 Change: 2016-10-14 18:42:17.374235446 +0800 $ touch --help | grep 'access time'   -a                     change only the access time   As you see, it was not only atime but also ctime which was updated by touch -a !?!?  The filesystem is ext4 over LVM if that makes any differences. can't create a jobs user profile Ubuntu 12.04 (Wubi) not starting - root.disk corrupted I have Ubuntu 12.04 installed through Wubi on my laptop. For some reason when i click on Ubuntu on start up (when you have to either select windows or Ubuntu) I get the following screen, the grub cursor keeps flashing.  Gnu grub version 1.99-21 Ubuntu 3.4   Minimal bash-like line editing is supported. For the first word, tab lists possible command completions. Anywhere else tab lists possible device or file completions.   grub&gt;   Could you tell me what I can do to fix this problem and to start Ubuntu normally? How do I customize the context menu in Nautilus? Proofs using theorems instead of axioms I'm not sure how to prove these basic theorems in propositional calculus. Instead of using the standard axioms, we're supposed to use:   Deduction Theorem (if $\Phi, \alpha \vdash \beta$ then $\Phi \vdash \alpha \to \beta$),  Reductio (if $\Phi, \alpha \vdash \, $, then $\Phi \vdash \lnot \alpha$), Cut Rule (if $\Phi \vdash \alpha$ and $\Psi, \alpha \vdash \beta$ then $\Phi \cup \Psi \vdash \beta$),  Inconsistency Effect (if $\Phi \vdash \, $, then $\Phi \vdash \beta$ for every formula $\beta$), and  the Principle of Indirect Proof (if $\Phi, \lnot \alpha \vdash \, $, then $\Phi \vdash \alpha$),    as all the axioms can be deduced using these theorems.  I don't really know how to start the proofs without using the axioms:  i) prove that $\lnot(\alpha \to \beta) ⊢ \alpha$  ii) prove that $\lnot\alpha \vdash \alpha \to \beta$  Any suggestions on how to start these proofs or any insight at all would be greatly appreciated!  Thanks! Relation bewteen Hessian Matrix and Curvature According to ,  It describes the local curvature of a function.   AFAIK, for one-variable function $f(x)$, its local curvature is  $$\kappa = \frac{|f''|}{(1 + f'^2)^{3/2}},$$ and its Hessian matrix is  $$\mathcal{Hess}(f) = [f''],$$ right? And here is my problem, I think the local curvature is not just described by its Hessian matrix, because $f'$ also has its role in it, doesn't it?  And furthermore, for 2-variable function $f(x,y)$, its Hessian matrix is  $$\mathcal{Hess}(f) = \left[ \begin{array}{cc} f_{xx}'' &amp; f_{xy}'' \\ f_{xy}'' &amp; f_{yy}'' \end{array} \right].$$ How does it relate to the local curvature of $f(x,y)$? Is symmetric group on natural numbers countable? Regex pattern to choose data BETWEEN matching quotation marks Elsarticle - Abstract two columns wide After a few days of operation on my new ec2 build, the following happens:   I log into SSH, everything is fine, I do my coding I return the next day, and log into SSH I cannot type a lower cased e anymore--I get the error ding when I type it I try to ssh from a different computer, same problem I reboot the server, same problem I open nano or vi and e works fine, just not in bash or sh I terminate the server, create a new one, install from scratch, a few days later it happens again   This is baffling! Where do I even start to troubleshoot?  My Local Machine Setup(s):   windows XP or 7 putty (latest) or cygwin/openssh   The EC2 setup   Amazon Linux (default options) node.js iptables forwarding port 80 to node on port 8003 emacs, npm, and openssl-devel no other mods       Output of stty -a while I can't type an e  sh-4.1$ stty -a speed 38400 baud; rows 30; columns 95; line = 0; intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = &lt;undef&gt;; eol2 = &lt;undef&gt;; swtch = &lt;undef&gt;; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; flush = ^O; min = 1; time = 0; -parenb -parodd cs8 -hupcl -cstopb cread -clocal -crtscts -cdtrdsr -ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr icrnl ixon -ixoff -iuclc -ixany -imaxbel -iutf8 opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0 isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke   In case it helps someone else with a similar issue, I created a script (called sub) to convert upper-cased E to lower-cased, then echo the command back. Then I run it in backticks to get an e on the command line::  #!/bin/sh echo ${@//E/e}  &gt; `sub Emacs /Etc/profilE`   UPDATES   This breaks for all users In bash only (csh works fine) In emacs edit mode only   I've created  and hone in the solution. Any gotchas I should be aware of?  Can I store it in a text field, or do I need to use a blob? (I'm not overly familiar with either pickle or sqlite, so I wanted to make sure I'm barking up the right tree with some of my high-level design ideas.) How do you programmatically set an attribute?