Can't switch on wifi
Is there a way to disable the hardware on/off switch for the Wireless interface?
Label equation with a symbol I would like to label an equation with an arbitrary symbol, rather than a number, or letter.  Is this possible? I'm trying to find $\int x^x \, dx$, but the only thing I know how to do is this:  Let $u=x^x$.  $$\begin{align} \int x^x \, dx&amp;=\int u \, du\\[6pt] &amp;=\frac{u^2}{2}\\[6pt] &amp;=\dfrac{\left(x^x\right)^2}{2}\\[6pt] &amp;=\frac{x^{2x}}{2} \end{align}$$  But it's certain that this isn't the correct way to evaluate that, and the answer must be wrong. How can I stand on the ground? EM or/and Pauli? Equivalence of definitions of prime ideal in commutative ring I'm trying to get Intel and Nvidia graphics card working together with two monitors. One monitor should use the Intel card and the other the Nvidia card. Of course, I want to use only one keyboard and one mouse to switch between both screens. Bumblebee didn't work for me.  I don't want to use the xserver-xorg-video-all package because I need the Nvidia card for gaming and I can't use only one graphics card because I need one for KVM virtualisation and the other one for my Linux desktop  So I tried to install the drivers and to configure the Xserver manually. The Nvidia driver is working and I get a video output. But I don't get a video output with the Intel card.  I followed   The config files: Learning special relativity and working with Minkowski diagrams for a while now i am still trying to get my head around some oddity.   From my understanding time can often be seen as the dependent variable in those diagrams, so why put it to the vertical axis? What confuses me even more is the apparent convention to denote a point in space time $(t,x)$ even though $x$ is on the horizontal and $t$ is on the vertical axis, so the usual notation would be to refer to that vector as $(x, t)$.  Are there mostly historical reasons or why is it beneficial to use this notation and to violate usual conventions? Variance of sample variance? What is the variance of the sample variance? In other words I am looking for $\mathrm{Var}(S^2)$.  I have started by expanding out $\mathrm{Var}(S^2)$ into $E(S^4) - [E(S^2)]^2$  I know that $[E(S^2)]^2$ is $\sigma$ to the power of 4. And that is as far as I got. C# - Keyword usage virtual+override vs. new What are differences between declaring a method in a base type "virtual" and then overriding it in a child type using the "override" keyword as opposed to simply using the "new" keyword when declaring the matching method in the child type? Why can't we see images reflected on a piece of paper? Let $a_n$ be a sequence s.t $a_1 > 0 \land a_{n+1} = a_n + \dfrac{1}{a_n}$. Prove that $a_n$ is increasing and tends to infinity Let $a_n$ be a sequence s.t $a_1 &gt; 0 \land a_{n+1} = a_n + \frac{1}{a_n}$. Prove that $a_n$ is increasing and tends to infinity.  Proof:   Consider $a_{n+1} - a_n$:  $a_{n+1} - a_n = a_n + \frac{1}{a_n} - a_n = \frac{1}{a_n}$ This is greater than $0$. Thus, $a_n$ is increasing.  Now this is where I need some help. I would like to say that $a_n$ is unbounded and then conclude that monotone and unbounded implies tending to infinity.  Maybe by contradiction? Which tools and technologies are used to build the Stack Exchange Network? What tools and technologies are used to build the Stack Exchange Network?  See also: I thought I remembered hearing the food agency  say that you should never reheat chicken meat after the initial cooking. However, I cannot find the statement of it anymore. Now I'm starting to suspect my memory.  Could this statement be true?  Is it unsafe to reheat chicken? When will "Present Perfect vs. Past Tense" cases be affected by culture? Regarding actions taken in the past, besides the differences those two tenses have semantically, my teacher shared that it could be a British vs American English case.   When talking about past action, British prefers present perfect because they take into account that the effect from their past action still happens until now. As for American, they prefer to state the action only. It happened in the past, so past tense it is.     I have had dinner. [British]   vs.      I had dinner. [American]   I hope to hear it from the native speakers, both British and American. What do you think about this? Is it true?  If it is, I don't think it can apply to all cases of past actions. There have to be cases when both style agree to use the same tenses. Could you please help me define the situation when this kind of difference applies and when doesn't? Moment generating function of the inner product of two gaussian random vectors Can anybody please suggest how I can compute the moment generating function of the inner product of two Gaussian random vectors, each distributed as $\mathcal N(0,\sigma^2)$, independent of each other? Is there some standard result available for this? Any pointer is highly appreciated. When is it useful to include the code in a thesis? I am writing my master of science thesis and I am not sure whether I should add some of the code I have written: they are not proper programs, but more like input files to be fed to a commercial program (Nastran) very popular in my field.  My concerns are related to the fact that I am not making any discovery, just applying the things I have learned reading the manual. Still, I feel the code will make the effort I put into the thesis to also learn this language clearer. Zombies - Why do they need to feed on living animals/humans? I have two directories that should contain the same files and have the same directory structure.  I think that something is missing in one of these directories.  Using the bash shell, is there a way to compare my directories and see if one of them is missing files that are present in the other? How do I use shell variables in an awk script? How do you disable browser autocomplete on web form field / input tags? Is there a CSS parent selector?