How to upgrade BasicTeX?
BasicTeX - how to identify packages that need to be added after an upgrade
I'm actually at the cemetery at White Orchard. There is a white question mark and some little red arrows.  What are this little red arrows?  Do they point to something dangerous? Let $f:\mathbb{R}\rightarrow \mathbb{R}$ be continuous.Let $t\in\mathbb{R}$. Evaluate:$\lim_{h\rightarrow0}\frac{1}{h}\int_{t-h}^{t+h}f(s)ds$ Can I use Bluray as a boot cd? Problem on Sum of Digits of a Number I was given this problem to Prove if $Q(n)=Q(2n)$ implies $9∣n$. Where $Q(n)$ be the sum of digits of $n$. I tried to use the fact that sum of digits is congruent to the number modulo $9$ but I had no luck. Any help is appreciated. Creation of entangled electrons GIS Point or discrete longitude and latitude columns? Let $f$ be a differientable real function such that $$(b-a)f'(\tfrac{a+b}{2}) = f(b)- f(a)$$ for all reals $a,b$.     Is $f$ polynomial of degree $\leq 2$ ? "In back of'' vs. "back of" vs. the spatial sense of "behind" in AmE What are the differences between "=" and "<-" assignment operators in R? An ideal whose radical is maximal is primary I've got to prove that an ideal $Q$ whose radical is a maximal ideal is a primary ideal. That is, I want to prove that if $xy\in Q$, then $x\in Q$ or $y^n\in Q$ for some $n&gt;0$.    I've been trying for a while and I'm not sure where to begin. All I've got is that if $\text{Rad}(Q)$ is maximal and by definition it's the intersection of all prime ideals $P_i$ containing $Q$, then it must be equal to each of these $P_i$. So there is only 1 prime ideal containing $Q$, namely $\text{Rad}(Q)$.  Could anyone point me in the right direction? Thanks for any replies. Has drupal abandoned drush? I've been away from drupal for 2-3 years. I just came back around and installed drush via composer () and now every time I try to use drush I get a message telling me that I should be using composer:  ~/sites/d7 $ drush version  Drush version : 9.0-dev-gd4a3872 ~/sites/d7 $ drush dl drupal-7.x  [notice] dl has been deprecated. Please build your site using Composer. Add new projects with composer require drupal/[project-name]. Use https://www.drupal.org/project/composer_generate to build a composer.json which represents the the enabled modules on your site.   I downloaded drupal 8 following these , but when I try to use drush in that project I get this message:  ~/sites/cfbtv/web $ drush dl devel This codebase is assembled with Composer instead of Drush. Use `composer update` and `composer require` instead of `drush pm-updatecode` and `drush pm-download`. You may override this error by [error] using the --pm-force option.   Is there something wrong with my local env, or is drush a thing of the past now? Find the number of solutions of $x^2=x\mod m$ for any integer $m$.  I was thinking about bringing the $x$ over to the other side and somehow apply chinese remainder thm. Proving that $\lim\limits_{x \to 0}\frac{e^x-1}{x} = 1$ What is the sum of the 'second half' of the harmonic series?  $$\lim_{k\to\infty}\sum\limits_{n=k+1}^{2k}{\frac{1}{n}} =~ ?$$  More precisely, what is the limit of the above sequence of partial sums? How to create a bootable Ubuntu USB flash drive from terminal? I don't understand an answer. Should I add a comment, or post a new question? I recently (today) asked a question that received what seems to be a clear, concise answer, but one that's beyond my ability to understand (I'm at the cut-and-paste stage with JavaScript, and the answer seems to assume more knowledge than I actually have).  Is it considered better to ask follow-up questions as comments to the answer given, or should I post "fresh" questions to Stack to help me understand the answer that's been given? Is there an option to output a manual page in a different language? I don't want to change the computer language completely, but only specific manual pages. For example  $ man -English man Man is a manual program … $ man -Russian man Инструцтия для Unix, BSD и Linux. … I have been reading for days about how to remove the Google Search Bar from the top of my Nexus 6 since I never use it. I have gotten mixed answers on exactly what file to delete and where it is.  I have heard quicksearchbar.apk but it's not in /system/app like in previous versions. Does anybody know where the file/files are I need to delete in order to get rid of the search bar, or else, how to remove it? Preferably not downloading another launcher, since I don't want to bloat my phone when I could reduce the size. Evaluating a sum involving binomial coefficient in denominator I came across the following sum: $$\sum_{k=0}^{\infty} \frac{(-1)^k}{(2k+1)^2}\frac{4^k}{{2k \choose k}}$$    I thought that this can be evaluated using the expansion of $\dfrac{\sin^{-1}x}{\sqrt{1-x^2}}$ but I couldn't make any use of it. Then I tried to use the following: $$\frac{1}{(2k+1)}\frac{1}{{2k \choose k}}=\frac{\Gamma(k+1)\Gamma(k+1)}{\Gamma(2k+2)}=\int_0^1 x^k(1-x)^k\,dx$$ but this didn't help either and now I am stuck.   Any help is greatly appreciated. Thanks!    EDIT:  The sum originated from the following definite integral:  $$\int_0^{\pi/2}\tan^{-1}(\sin x)\,dx$$ If the quotient group $G/N$ be isomorphic to $G_2$, is $G$ isomorphic to $G_1\times G_2$ where $N$ is isomorphic to $G_1$?