Insert the „Ubuntu 20.04.2 LTS _Focal Fossa_ - Release amd64 (20210204)” called CD to the /cdrom/ drive and press enter So I have ran into some trouble installing g++. When I try to use the &quot;sudo apt install g++&quot;, command it asks me if I really want to install it, and when I say yes, it just leaves me this message: &quot;Insert the „Ubuntu 20.04.2 LTS Focal Fossa - Release amd64 (20210204)” called CD to the /cdrom/ drive and press enter&quot; (Or something like that, I tried to translate it from Hungarian) I give you an image of my problem, however my Ubuntu is in Hungarian, so i don't think that it would be useful. Here it is:  I have already tried to get the .iso file and just mount it to my cd drive, but it didn't solve the problem. Should I just reinstall Ubuntu or what should I do?
How can I avoid "please insert CD/DVD" error when updating Ubuntu? I can't update 12.04 LTS. The Update Manager shows this:  CD/DVD 'Ubuntu 12.04 LTS _Precise Pangolin_ - Release i386 (20120423)' is required Please insert the above CD/DVD into the drive '/media/cdrom/' to install software packages from it.   The image I downloaded and burned to CD is from  the PC (Intel x86) desktop CD version. I burned many CDs but the result is the same.
Downgrading from SQL Server 2008 to 2005 The question of  made me wonder as to whether wizards, any of them, do practice religion. Whether there be magic-person only religions or shared muggle faiths, I do not recall any wizards (born in the wizard world anyway) saying that they did practice a religion.  Many of them do celebrate Christmas, but as was commented on the above linked question, there are many non-christian muggles that also observe Christmas. So I am not sure that can be an accurate identifier. Answering this question may link into identifying . Consider there is a box of mass $m$ at rest on the floor. Most books give an example that we need to do a work of $mgh$ to lift the box $h$ upward.  If we analyze this work done, the external force acting on the box by us should be equal to the weight of the box. Therefore the net force is zero which in turn there is no acceleration. If there is no acceleration and the initial velocity of the box is also zero, how can the box move upward? What's the meaning of "be blowed"? I would like to know what's the meaning of "be blowed" in the following text:     'I'm going to smoke' Jenkins said; 'be blowed to Bertie dear.' (Mrs. Smythe had once addressed her husband in the office as 'Bertie dear', and thereforth that had been his name among the staff.) Richard made no answer. When a minute later Jenkins, discreetly directing his puffs to the open window, asked him for the titles of one or two of Zola's novels in English, and their price, he gave the required information without turning round and in a preoccupied tone.   , Arnold Bennett, 1911. E: Malformed entry 54 in list file /etc/apt/sources.list (Component) Execute function when post is published I try to use this function i have created when a post is published for the first time.  function a_new_post($post){   $post_id = $post-&gt;ID;    if ( !get_post_meta( $post_id, 'firstpublish', $single = true ) ) {       // ...run code once       update_post_meta( $post_id, 'firstpublish', true );   } } add_action( 'draft_to_published', 'a_new_post' );   I can't see anything wrong with it, but when i try to create some sample posts i check the database and the field "firstpublished" has not been created.  Does anyone see anything wrong? I added a user to a group, but group permissions on files still have no effect I drew a parallelepiped that is spanned by three vectors, and we know the volume is given by the absolute value of the determinant of the matrix - with the three vectors arranged in rows (or columns, since $detA = detA^T$).  How can I draw the tetrahedron from this parallelepiped to convince myself it is indeed 1/6th of the volume, i.e., 1/6 * |detA|?  Thanks, Run a GUI program at startup I constantly stay up to date with each new release of Blender, but this means my preferences are wiped clean each time. How do I export/import these preferences to avoid loosing my carefully crafted set up each time? Calculation of $\lim_{n\to \infty}\prod_{r=1}^{n} \left(1+\frac{r}{n}\right)^{\frac{1}{n}}$ Calculation of  $\displaystyle \lim_{n\to \infty}\prod_{r=1}^{n} \left(1+\frac{r}{n}\right)^{\frac{1}{n}}$  $\bf{My\; Solution::}$  Let $y=\displaystyle \lim_{n\to \infty}\prod_{r=1}^{n} \left(1+\frac{r}{n}\right)^{\frac{1}{n}}$, Now taking $\log_{e}$ on both side  $\displaystyle \log_{e}(y) = \lim_{n\to \infty}\log_{e}\left(\prod_{r=1}^{n} \left(1+\frac{r}{n}\right)^{\frac{1}{n}}\right)=\lim_{n\to \infty}\frac{1}{n}\cdot \sum_{r=1}^{n}\log\left(1+\frac{r}{n}\right)$  Now Using Reinman Sum of Integral ...  $\displaystyle \log_{e}(y) = \lim_{n\to\infty}\frac{1}{n}\cdot \sum_{r=1}^{n}\log\left(1+\frac{r}{n}\right) = \int_{0}^{1}\ln(1+x)dx = \log_{e}(4)-\log_{e}(e) = \log_{e}\left(\frac{4}{e}\right)$  So $\displaystyle y =\lim_{n\to \infty}\prod_{r=1}^{n} \left(1+\frac{r}{n}\right)^{\frac{1}{n}} =\frac{4}{e}$  But how can i solve above question using Stirling Approximation,  May I ask for help?  Thank you in advance! Show $\sin x = bx$ has at least 3 real solutions. Show $\sin x=bx$ has at least 3 real solutions for every $b$, where $-\dfrac{2}{3 \pi} &lt; b &lt; \dfrac{2}{\pi}$.   Some useful facts I am trying to use:  Intermediate value theorem: If $f$ is a continuous real-valued function on $[a,b]$ and $d \in \mathbb{R}$ satisfies $f(a)&lt; d&lt; f(b)$, then there exists a point $c$ in $(a,b)$ such that $f(c) = d$.   Corollary: If $f$ is a continuous real-valued function on $[a,b]$, then $f([a,b])$ is a closed interval. How to convert PDF to (La)TeX? I know that hardly any information is passed to the PDF when a .tex file is compiled.  But is there a tool that can convert a PDF document back to (La)TeX? I have  $m\times n = n + n + \dots + n$    in my text right now, but I would like to put a curly brace under the \dots to emphasize that there are m,n's involved. How would I do this? How to invoke vim editor and pipe output to bash When the trace of the Frobenius homomorphism is zero? Let's consider an elliptic curve over a finite field $\mathbb F_p$.  The trace of the Frobenius homomorphism is defined as:  $$a_p=p+1-\#E(\mathbb F_p)$$  See for example .  I read that this value is zero if and only if the elliptic curve is supersingular. Unfortunately there is no proof give. So I am looking for a proof of this. (For example a good reference). Is it true that $0.999999999\ldots=1$? I'm told by smart people that $$0.999999999\ldots=1$$ and I believe them, but is there a proof that explains why this is? Possible Duplicate:             Well, I remembered this after having Algebra II a year ago, is it possible that this is a valid proof that $1 = -1$?  $$ 1 = \sqrt{1} = \sqrt{-1\cdot-1} = \sqrt{-1} \cdot \sqrt{-1} = i \cdot i = i^2 = -1 $$  $$ \therefore 1 = -1 $$  So is this actually fully valid? Or can it be disproved? I have a small utility that I use to download an MP3 file from a website on a schedule and then builds/updates a podcast XML file which I've added to iTunes.  The text processing that creates/updates the XML file is written in Python. However, I use wget inside a Windows .bat file to download the actual MP3 file. I would prefer to have the entire utility written in Python.  I struggled to find a way to actually download the file in Python, thus why I resorted to using wget.  So, how do I download the file using Python? new array.sty and colortbl.sty incompatibility? I just upgraded my texlive distribution and can no longer insert space in table rows using \\[x pt] syntax when colortbl is loaded.  It seems that recent changes to array.sty might be the problem as this is the only package to change recently.  Can anyone suggest a workaround?  MWE  \listfiles \documentclass{article} \usepackage{colortbl} \begin{document} \begin{tabular}{l}   \hline   No space below with \texttt{colortbl.sty} loaded. \\[10mm]   \hline \end{tabular} \end{document}   File versions in use:   article.cls    2014/09/29 v1.4h Standard LaTeX document class   size10.clo    2014/09/29 v1.4h Standard LaTeX file (size option) colortbl.sty    2012/02/13 v1.0a Color table columns (DPC)    array.sty    2018/04/07 v2.4g Tabular extension package (FMi)    color.sty    2016/07/10 v1.1e Standard LaTeX Color (DPC)    color.cfg    2016/01/02 v1.6 sample color configuration   pdftex.def    2018/01/08 v1.0l Graphics/color driver for pdftex