Erratic Cursor: Laptop Touchpad Driver?
Ubuntu touchpad issues - mouse pointer jumps around
Math people:  The title is the question. I am convinced that uncountable sets exist, thanks to Cantor's diagonal proof.  It is not intuitively clear to me that uncountable ordinals or cardinals should exist.  What axioms of set theory are needed to accept their existence?  I think I have read here that the Axiom of Choice is not necessary.  I am reluctant to accept as "true" any theorems that rely on the Axiom of Choice.  EDIT: This question may be a duplicate: I just found  .  I apologize if this is so. Google Chrome: Have different settings on different computers? I'd like to modify the names used to typeset some of my document elements. For example, the caption of figure floats should change from "Figure" to "Fig.", and my \tableofcontents sectioning heading shouldn't read "Contents", but "Table of Contents". How can I do that?  \documentclass{article} % \usepackage[english]{babel} \begin{document} \tableofcontents \section{foo} \begin{figure}[h] \centering \rule{1cm}{1cm}% placeholder for graphic \caption{A figure} \end{figure} \end{document} Is there a standard naming convention for XML elements? Is there any standard, de facto or otherwise, for XML documents? For example which is the "best" way to write a tag?  &lt;MyTag /&gt; &lt;myTag /&gt; &lt;mytag /&gt; &lt;my-tag /&gt; &lt;my_tag /&gt;   Likewise if I have an enumerated value for an attribute which is better  &lt;myTag attribute="value one"/&gt; &lt;myTag attribute="ValueOne"/&gt; &lt;myTag attribute="value-one"/&gt; So this is a question with which I have been stuck for a while and it all revolves around the concept of volt.  I have posted a LOT of questions on physics forums while trying to understand the concept of volt and potential difference. This is hopefully going to be the last one.  What do you exactly mean when you say that a battery is 2.5 V. I know that it says that the potential difference between the 2 terminals of the battery is 2.5 V  but then what is the potential of the 2 ends of the battery? Is there a unit of potential and not just potential difference?  Also volt = work/charge but how can work/charge express the difference of potentials across the 2 terminals? \includegraphics cannot handle filenames that contain more than the one dot, separating the filename from the extension. Apparently it uses everything after the first dot as extension and then, of course, complains about an unknown graphics extension.  This is annoying as I very often have filenames that contain parameter values, e.g. plot_a0.4_b0.6.pdf.  Is there a way to teach LaTeX to interpret only the string behind the last dot as extension? 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 completely remove kubuntu-desktop from Ubuntu I installed kubuntu-desktop just to experiment with its interface.  Then I decided to remove and did the traditional apt-get purge and autoremove but it seems elements of kubuntu are still there. For example interface elements, scrollbars, bootscreen etc are still there.  Is there any method I can completely remove without installing a fresh copy of ubuntu? I'd like to add an invisible watermark to each PDF document that I produce so that in case it leaks, I know where it leaked from. Anyone knows what would a good way for an invisible watermark be in a PDF document and how to add one? Could it be that Goldbach conjecture is undecidable? Why is the observable universe so big? The observable universe is approximately 13.7 billion years old. But yet it is 80 billion light years across. Isn't this a contradiction? Hadamard Product of $e^z-1$ Assuming the formulas $$\sin(z)=\frac{e^{iz}-e^{-iz}}{2i}\quad\text{and}\quad\frac{\sin(\pi z)}{\pi z}=\prod_{n=1}^\infty\left(1-\frac{z^2}{n^2}\right),$$ I want to find the Hadamard product of $e^z-1$. I think I've done the work correctly, but I end up having an extra factor of $2\pi i$ at the end (this is from Stein and Shakarchi's book and they list the answer for this particular problem). So, my work is \begin{align} e^z-1&amp;=e^{z/2}\left(e^{z/2}-e^{-z/2}\right)\\ \\ &amp;=e^{z/2}\left(e^{i(-iz/2)}-e^{-i(-iz/2)}\right)\\ \\ &amp;=2ie^{z/2}\left(\frac{e^{i(-iz/2)}-e^{-i(-iz/2)}}{2i}\right)\\ \\ &amp;=2ie^{z/2}\sin(-iz/2)\\ \\ &amp;=2\pi i ze^{z/2}\frac{\sin(-iz/2)}{\pi z}\\ \\ &amp;=2\pi i ze^{z/2}\frac{\sin\left(\pi(\frac{-iz}{2\pi})\right)}{\pi z}\tag{*}\\ \\ &amp;=2\pi i ze^{z/2}\prod_{n=1}^\infty\left(1-\frac{\left(\frac{-iz}{2\pi}\right)^2}{n^2}\right)\\ \\ &amp;=2\pi i ze^{z/2}\prod_{n=1}^\infty\left(1+\frac{z^2}{4n^2\pi^2}\right). \end{align}  The answer according to the book is $$e^z-1=e^{z/2}z\prod_{n=1}^\infty\left(1+\frac{z^2}{4n^2\pi^2}\right).$$Have I made a simple mistake in calculation, or are the two somehow compatible with each other?  Update: Thomas Andrews has pointed out a mistake in my infinite product formula. I've corrected that mistake.  $(*)$ The error occurs from this line to the next. Instead of multiplying and dividing by $z$, I should have multiplied and divided by $\frac{-iz}{2\pi}$. That would cause the appropriate cancellation. "Total number of votes for 'N' answers" is wrong in "Deleted Recent Answers" Below are the two screenshots. First one shows the number of votes          In above image a post which was deleted shown ) votes. Now in below image which is actual post deleted is having 1 vote. How to initialize a JavaScript Date to a particular time zone If $Y|X \sim \mathcal{N}(0,1)$ then is $Y^2|X \sim \chi^2(1)$? Suppose we have random variables $X$ and $Y$ such that $Y|X \sim \mathcal{N}(0,1)$. Can we then say that $Y^2|X \sim \chi^2(1)$? If we can, then what about when $Y|X \sim \mathcal{N}(0,\sigma^2/4)$, can we use the results of  to say that $Y^2|X \sim \frac{\sigma^2}{4}\chi^2(1)$? Essentially I want to know if the results of squaring a normal distribution can be applied to the case where a random variable is conditionally normally distributed? Estimating Uniform distribution endpoints using data with errors Suppose I have a random variable $X$ ~ $Unif(0,\theta)$ where I want to estimate $\theta$. I draw a sample $X_1,...,X_n$.One way is to get a point estimate using e.g.  maximum likelihood estimation via the sufficient statistic $X_{(n)}$.  However, suppose I want a 95% confidence interval of sorts on the value of $\theta$, how should I construct one?  The reason why I am interested in confidence interval is because of the following issue, which is actually my main question (the above prelude on confidence interval is just a suggestion on possible approach). So actually my sample came with some noise, in a sense that I actually observe $X_1+E_1,...,X_n+E_n$ where $E_i$~$N(0,\sigma_i^2)$ independently from each other and from the $X$'s. How should I make some form of statistical estimation about $\theta$? I would prefer some form of confidence estimate. Should I use 'or' or 'nor' after a negative statement? Can't get my model out of wireframe mode I'm new to Blender and this site, so I apologize in advance if I'm not following any of the proper etiquette.  I'm no artist, but I'm trying to learn Blender so that I have some programmer art for me to work around in Unity.    I followed a tutorial for making a basic human model, I rigged it with rigify, and now I'm starting to export it following yet another tutorial.  The thing is, when I was trying to rig the model, I couldn't get the model to go transparent so that I could see the bones inside the model.  Eventually, I managed to get it into wireframe mode, but I can't get it back into solid mode.    It's probably just a display thing and not a property of the model itself, but I want to be sure.  I'm looking at the display options under the "Figure" pane in Blender, and none of the Display check boxes are checked, including the one that says "Wire".  I don't want to import a plain wireframe model into Unity, and even if that doesn't happen, this is functionality of Blender that I should really know anyway, so I'd appreciate any help that anyone has to offer.  If necessary, I can upload the .blend file, but I'm not sure what site people would prefer that I upload it to. Can I configure it to allow:   select right-click to copy right-click or ctrl-v to paste? I find it very strange that $$ e^x \geq x^e \, \quad \forall x \in \mathbb{R}^+.$$   I have scratched my head for a long time, but could not find any logical reason. Can anybody explain what is the reason behind the above inequality? I know this is math community, but I'd appreciate a more intuitive explanation than a technical one.