Extracting sheet/pages from Excel XLXS file to Mathematica
import Excel sheets by name
Allow only alphanumeric characters for a UITextField How will learning about philosophy impact real-life? Examining the practical, impactful, real-life benefits of getting a degree in philosophy It is often asked, &quot;What is the practical use of philosophy?&quot; or &quot;How will learning about philosophy impact real-life?&quot; It is easy to see why there is such mystery surrounding the topic. Most schools up through high school may only offer 1 or 2 courses on it, if any. It is also often talked about in general conversation as a &quot;wishy-washy&quot; subject, often negatively, as though it contains no answers but only raises an endless series of questions. To add to this, those who hear of the subject but know very little of it may be surprised to see it offered at their university as a major. It is clear to most why some people would want to major in Computer science, Mathematics, or Physics. But what would a degree in philosophy get you? Every natural number $n$ can be written as $n=s-t$ with $\omega(s)=\omega(t)$ Can we prove the following statement ?  Let $\omega(m)$ denote the number of all distinct prime factors of a positive integer $m$. Prove that every  natural  number $n$ can  be  written  as $n=s-t$, where $s$ and $t$ are positive integers with $\omega(s)=\omega(t)$, in other words, as the difference of two positive integers with the same number of distinct prime factors.   If $n=1$ , we can choose $\ s=3\ $ and $\ t=2$.  If $n$ is even , we can choose $\ s=2n\ $ and $\ t=n$. Algebraic proof of $\sum_{i=0}^k{{n \choose i}{m \choose {k-i}}}= {{m+n}\choose k}$ I can't figure out an algebraic proof for the following identity:  $$\sum_{i=0}^k{{n \choose i}{m \choose {k-i}}}= {{m+n}\choose k}$$  Combinatorical solution:  We can see that as choosing some from $n$ and the rest of $k$ from $m$, thus $k$ in total.  Or we could just choose $k$ from the union. What is the plural form of "Software"? Is it correct to use softwares, as in the following sentence?  There are various video conversion softwares in the market. Word meaning the reverse of 'Xenophobia' Xenophobia refers to the irrational fear or hatred of foreigners. But recently I've seen people displaying (in newspaper articles and other places) an irrational fear or hatred of their own countrymen. Is there a word for that? I have a sword that currently rotates around a pivot point thats off of the actual object. Im new to blender and im not sure how i would go about changing it so that the sword rotates around the handle. Any help would be appreciated! Density of Solid States of Compounds One of the wonderful properties of water (as my high school biology teacher would say) is that in its solid form, it is lighter than its liquid form. This means that when temperatures drop below 0 degrees Celsius, the top layer of water on, say, a lake freezes first. This works out pretty well for any fish or other aquatic creatures living underneath, because the lower layers of water will not freeze.  I know that this is an exception to the general rule of solid and liquid states: A given substance, when transformed into its solid state, will generally sink in a container of its liquid state. My question is this: What other substances are exceptions to this rule (if any?). What features do they share with water that are responsible for this? Integral of the square of the normal distribution. What does the '=>' syntax in C# mean? I just came over this syntax in some of the questions in this forum, but Google and any other searchengine tends to block out anything but letters and number in the search so it is impossible to search out "=>".  So can anyone tell me what it is and how it is used? Is it safe to delete from C:\Windows\Installer? I've been looking on an XP machine what is using all that diskspace, and it turns out C:\Windows\Installer is high up there on the list of directories that use the most diskspace.  It seems to contain a cache of msi and msp files.  Is it safe to delete those? To save diskspace, I've been deleting the "$KB...$" directories for ages without any problems. I want my Windows Updates in my system, why you would want to uninstall them is something that I have never understood. (Except when you're on an update revision board professionally or something of that order.) No Time in Top Panel (Gnome Classic) I've been using Ubuntu with Gnome Classic for a while and I've noticed recently that in the "Indicator Applet Complete" in the Top Panel, my name and the clock have disappeared.    I think it happened a while ago when I was messing around with packages. Every time I did apt-get... it would say "the following packages can be removed by apt-get autoremove", so I did it and then the clock and my name stopped appearing.   Can anyone help me? Thanks. It would be greatly appreciated. "Fatal error: Cannot redeclare " I have forgotten my Facebook account password and also I have no access to the number which I use to log-in to Facebook account.   On this page (see the image below) they are asking for a government photo-ID to verify my account. The problem is that I don't have a driving license, voter ID card, passport etc. All I have is a school ID card but that hasn't worked for me. Is there any other way to recover my password? I want to put the section title in the left margin using titlesec. However, it results to a superfluous empty line when using list environment. How should I remove it without using vspace?  Minimal example:  \documentclass{article}  \usepackage{geometry} \geometry{   a4paper,   top=2cm,   bottom=2cm,   left=4.5cm,   right=1.5cm, }  \usepackage{titlesec} \titleformat{\section}[leftmargin]{\large\scshape\sffamily}{}{0cm}{} \titlespacing{\section}{2.5cm}{2ex}{0.5cm}  \usepackage{enumitem}  \usepackage{mwe}  \begin{document}  \section{Section A}  This line is aligned with the section title.  \blindtext  \section{Section B}  \begin{itemize}[nosep]   \item This line is not aligned with the section title. \end{itemize}  \end{document} Stop the Ubuntu updater from nagging about Firefox English Language pack even after uninstalling Firefox I have run sudo apt purge firefox, and I have gone through all of the /.config files, etc., and Software Updater is still asking me daily if I want to install the &quot;English Language Pack for Firefox&quot;. I don't have Firefox installed. How can I stop the updater from asking to update something on a program that doesn't exist? Output of dpkg -l | grep firefox: ii  firefox-locale-en                          88.0+build2-0ubuntu0.18.04.2        amd64        English language pack for Firefox What packages do people load by default in LaTeX? Delete all lines in Notepad++ except lines containing a word I need? I need to calculate the following indefinite integral:  $$I=\int \frac{1}{\cos^3(x)}dx$$  I know what the result is (from Mathematica):  $$I=\tanh^{-1}(\tan(x/2))+(1/2)\sec(x)\tan(x)$$  but I don't know how to integrate it myself. I have been trying some substitutions to no avail.   Equivalently, I need to know how to compute:  $$I=\int \sqrt{1+z^2}dz$$  which follows after making the change of variables $z=\tan x$. Does a Warlock receive the benefit of their familiar's Magic Resistance trait? The Warlock has access to special forms for their find familiar spell through the Pact of the Chain feature. I'm wondering if these special forms, the Quasit, Imp, and Pseudodragon in particular, allow the player character to share the familiar's Magic Resistance feature. In the Monster Manual each of these creatures has a sidebar that states that the familiar shares its Magic Resistance feature with the companion they are bonded to, but the PHB doesn't mention this in any of the creatures' stat blocks.   For example, in the Variant: Pseudodragon Familiar sidebar on page 254 of the MM it says:     "While the pseudodragon is within 10 feet of its companion,        the companion shares the pseudodragon's Magic Resistance trait."   This feature seems clear in the MM but I'm led to believe that it wasn't intended for Player Characters since mention of it is absent from the stat blocks in Appendix D of the PHB (pages 307-309).  Would a 3rd level warlock who chose one of these familiar forms through the Pact of the Chain feature benefit from advantage from saving throws from spells and other magical effects due to these special forms, or was this feature only meant for powerful NPCs and enemy spellcasters who had made this link with these familiars themselves?