How to boot Ubuntu from grub?
How do I boot my PC from GRUB?
Let $F$ be a field and $x\in F$. If $x=-x$ and $1\neq -1$, then $$0=\frac{x+x}{1+1}=\frac{1+1}{1+1}x=x.$$ This means that the statement in the title is true if and only if $1\neq -1$. But how do we know that $1\neq -1$ for an arbitary field? How do I enable hibernation on Wubi? I installed Ubuntu on my Windows 7 Sager laptop using Wubi. Hibernate (i.e. suspend to disc) is not an option from the power icon, only suspend, shutdown, etc. Hibernate is also not an option from my battery/lid close options. I understand that hibernation is disabled by default in Ubuntu 12.04. I tried running pm-hibernate but I get the following message:  Looking for splash system... none  s2disk: Snapshotting system   and then the computer just hangs with a black screen. According to the documentation  if this fails then I can't enable hibernate but it offers no help in making pm-hibernate succeed.  Could swap be my problem? It looks like I have very small swap:  user@ubuntu:~$ cat /proc/swaps Filename                Type        Size    Used    Priority /host/ubuntu/disks/swap.disk            file        262140  0   -1   The advice on  is only for the author's set up (e.g. I don't have an Ubuntu install disk since I used Wubi) and he says that 'INFO: This will not work for 12.04, resume from hibernate work differently in 12.04.'  Any advice? I really need to get hibernate working to use my laptop as a, er, laptop.  Thanks Can a multiclass sorcerer make spell slots for their other class using sorcery points?  For example: can a multiclassed sorcerer 3 / warlock 1 use Flexible Casting to create a warlock spell slot? Derivative of $(y-XB)' h(y-XB)$ with respect to $B$ Is there a dominant gene for right-handedness? Has there been any definitive research about handedness being genetic? Also, why is right-handedness clearly dominant in humans? I'm interested in evolutionary theories, as well as any molecular explanation (if known). Bounding the integral $\int_{2}^{x} \frac{\mathrm dt}{\log^{n}{t}}$ If $x \geq 2$, then how do we prove that $$\int_{2}^{x} \frac{\mathrm dt}{\log^{n}{t}} = O\Bigl(\frac{x}{\log^{n}{x}}\Bigr)?$$ From Wikipedia: Fermi was known for his ability to make good approximate calculations with little or no actual data, hence the name. One example is his estimate of the strength of the atomic bomb detonated at the Trinity test, based on the distance travelled by pieces of paper dropped from his hand during the blast. Fermi's estimate of 10 kilotons of TNT was remarkably close to the now-accepted value of around 20 kilotons, a difference of less than one order of magnitude.  I have not been able to find any references explaining how he made this calculation. Please provide a reference or an example calculation.  See also: Is there such a thing as a switch that can be actuated automatically? I'm interested in a toggle switch that can be toggled without user input. That is, the physical state can be toggled electrically. It would need to incorporate some sort of motor or magnetic actuator. My google-fu is weak in this area, and I haven't been able to come up with the correct combination of search terms.  Note that I'm not talking about a relay; I'm talking about a normal toggle switch:    Except that it can be toggled without user input. As in, the lever physically moves. Like a  except that the mechanism is internal to the switch. jQuery - auto size text input (not textarea!) Debugging errors of SAGA interpolation algorithms in QGIS Processing? I encounter recurrent problems with the geoalgorithms that perform interpolations. No matter what technique I use I end with the following errors. As stated in the OGR tab QGIS 2.0 is unable to open a file in C drive. I have very little IT background so the message error is meaningless.   Is there anybody able to decrypt the message and solve the problem?      here this is the algorithm i used pgfplots from file: search path, looking for \graphicspath equivalent Show that a matrix $A$ is singular if and only if $0$ is an eigenvalue. I can't find the missing link between singularity and zero eigenvalues as is stated in the following proposition:  A matrix $A$ is singular if and only if $0$ is an eigenvalue.  Could anyone shed some light? Smallest positive element of $ \{ax + by: x,y \in \mathbb{Z}\}$ is $\gcd(a,b)$ Let $S = \{ax + by: x,y \in \mathbb{Z}\}$  and let $e &gt; 0$ be the smallest element in $S$. Prove that $e \mid a$, and hence prove that $e = \gcd(a,b)$  I'm afraid I can't provide much of my initial working here because I'm at a loss of how to start.  I suppose that to show $e\mid a$ I would have to show that $eg = a$ for some $g \in \mathbb{Z}$. But I have no idea how I would do this. How to prove that $\lim \limits_{n\rightarrow \infty} \frac{F_{n+1}}{F_n}=\frac{\sqrt{5}+1}{2}$ How do I write a mathematical equation for ARIMA (2,1,0) x (0,2,2) period 12 Page layout assignments with XML metadata API How do I define page layout assignments for different record types via metadata XML files? Assume $f:A\to A'$ is a function, $B\subset A'$, $C\subset A'$, and $f^{-1}(B\cap C)=\emptyset$  How can we see that $f^{-1}(B)\cap f^{-1}(C)=\emptyset$? File l3backend-pdfmode.def not found when loading expl3 I updated my TeXlive distribution a couple times in the past week, and now I get this error when I include package expl3 (or any other package that includes it, such as fontspec). Before the updates it was working fine. Am I missing any package that should be installed? I tried searching for l3backend-pdfmode.def, but I found no results.  \documentclass{article} \usepackage{expl3} \begin{document} Hi \end{document}   λ lualatex a This is LuaTeX, Version 1.10.0 (TeX Live 2019)   restricted system commands enabled. (./a.tex LaTeX2e &lt;2018-12-01&gt;  luaotfload | main : initialization completed in 0.042 seconds (/opt/texlive/2019/texmf-dist/tex/latex/base/article.cls Document Class: article 2018/09/03 v1.4i Standard LaTeX document class (/opt/texlive/2019/texmf-dist/tex/latex/base/size10.clo)) (/opt/texlive/2019/texmf-dist/tex/latex/l3kernel/expl3.sty (/opt/texlive/2019/texmf-dist/tex/latex/l3kernel/expl3-code.tex)  ! LaTeX Error: File `l3backend-pdfmode.def' not found.  Type X to quit or &lt;RETURN&gt; to proceed, or enter new name. (Default extension: def)  Enter file name:  ! Emergency stop. &lt;read *&gt;   l.282   }   379 words of node memory still in use:    2 hlist, 1 rule, 1 dir, 3 kern, 1 glyph, 4 attribute, 48 glue_spec, 4 attrib ute_list, 1 write nodes    avail lists: 2:9,3:3,4:1,5:2,7:2,9:2 !  ==&gt; Fatal error occurred, no output PDF file produced! Transcript written on a.log. Installing AMD & Intel dual graphics Tenure and tenure denial rates by universities Is there a way or website to find the tenure and tenure denial rates by universities and departments? I heard from some faculty that the tenure rate at X university is Y%, so I wonder if there is a way to find the statistics for all universities.