unable to run sudo apt-get update $ sudo apt-get update Hit:1 http://dl.google.com/linux/chrome/deb stable InRelease                    Get:3 http://security.ubuntu.com/ubuntu eoan-security InRelease [97.5 kB]       Hit:4 http://archive.ubuntu.com/ubuntu eoan InRelease                           Get:5 http://archive.ubuntu.com/ubuntu eoan-updates InRelease [97.5 kB]         Ign:2 https://download.rethinkdb.com/apt eoan InRelease                         Err:6 https://download.rethinkdb.com/apt eoan Release                             404  Not Found [IP: 167.172.11.96 443] Reading package lists... Done                                                   E: The repository 'http://download.rethinkdb.com/apt eoan Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.  How can I fix this problem?
What can I do if a repository/PPA does not have a Release file? When updating, I get the following error message:   W: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu xenial Release' does not have a Release file.   Here, I find another statement on this error:   This recommends removing certain PPAs; and, I'm not sure if I should do that since it might mean not getting the updates that I need.    Is this what I should do?
Why do universal constants have the values they do? Use Results of Find Command to Call vi Is there a way that I can pipe the output of this command (assuming there is only one file found) to vi.  I want to find this command, and then call it up in vi.  Thanks.  find . -name 'id.properties' So I have an old unlocked phone and I'd like to load up my own OS.  I've seen some mods out there.  CyanogenMod seems to be the most popular.  However, I was curious if I could just install a pure untouched version of the OS -- as distributed by Google. I seem to remember being able to download a clean compiled version of the Android OS.    Does Google distribute any binaries like this, and if not, is there someone out there that does?    Additionally, is this even worth trying?  These days is it necessary for Android to be packaged with special drivers and such for all of the different hardware out there? I got a visa with my mother when I was 17 years old. On it was stated "Not valid unless accompanied by my mother".    Can I travel to the UK alone now that I am 18? Opening website external links in new window -- published usability tests By just typing some commands, how can Ubuntu be uninstalled? I don't want to install Windows or anything, leaving my PC without an OS.  Would this command work?  sudo rm -rf / Can a virtualized machine have the CPU and RAM resources of multiple underlying physical machines? I was working on a Beamer presentation, and noticed that, if I open a group scope and use a \tiny, the font size will bet set, but there will be a large space between lines. However, if I issue a \par at the end of the paragraph, it works as intended:  \documentclass[t]{beamer} \newcommand{\shortlipsum} {Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Ut purus elit, vestibulum ut, placerat ac, adipiscing vitae, felis. Curabitur dictum gravida mauris. Nam arcu libero, nonummy eget, consectetuer id, vulputate a, magna. Donec vehicula augue euneque. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas. Mauris ut leo. Cras viverra}  \begin{document} \begin{frame} \shortlipsum  {\tiny \shortlipsum\par   % &lt;--- removing this \par will break line spacing } \end{frame} \end{document}   Here's a comparison between not using and using \par:    Am I doing it the right way? Why is \par the right way? Is this algebraic identity obvious? $\sum_{i=1}^n \prod_{j\neq i} {\lambda_j\over \lambda_j-\lambda_i}=1$ If $\lambda_1,\dots,\lambda_n$ are distinct positive real numbers, then  $$\sum_{i=1}^n \prod_{j\neq i} {\lambda_j\over \lambda_j-\lambda_i}=1.$$ This identity follows from a probability calculation that you can find at the  top of page 311 in the 10th edition of Introduction to Probability Models by Sheldon Ross.   Is there a slick or obvious explanation for this identity?   This  question is sort of similar to ; clearly algebra is not my strong suit! "All sites" overview should not require scrolling when selecting a site What does the following for loop syntax mean in C? Explain travel times and distances on flight A flight from Los Angeles to ABQ is about 2 hours but is ~670.2 miles  A flight from San Jose to Chicago is 4 hours but is ~1859.0 miles  Can anyone explain why the travel time from San Jose to Chicago is not longer and closer to 5.75 hours?  If the distance increase by 2, shouldn't the time increase by a factor of 2 as well? From what I've seen it looks to me like Libav's avconv is thought to become a successor of ffmpeg — is that correct?   If that's true, why is that so? What exactly is libav doing better and why would I want to choose it over ffmpeg?   I came to this "issue" while installing Ubuntu 12.04.1 LTS in a VM and when I've installed ffmpeg it came up with a message telling mit ffmpeg is deprecated and I first thought "wtf?".  If I use avconvWill I be able to migrate my scripts depending on ffmpeg more or less easy to libav? I'm mostly using it for writing meta data and doing audio conversion (wav, flac, vorbis, mp3, aac). GParted can't resize partition, but unallocated partition is available Is flair tab working correctly? Is the flair tab working correctly?  It is counting aproximately 3 times more points and over 2 times more bronze badges at the time I'm posting it. Number of ways a natural number can be written as sum of smaller natural number It is easy to realize that given a natural number N the number of doublets that sum N are $\frac{N+(-1)(N \pmod 2)}{2}$ , so I thought I could reach some recursive formula in the sense that found the number of doublets I could find the number of triplets and so on ...,  example: N=3 the only doublet is 2+1=3 -not said yet but 2+1, and 1+2 count as one- then I could count the number of way the number 2 can be expressed as the indicated sum and got the total number of ways 3 can be written as a sum. But this seems not so efficient, so I was wondering if there is other way to attack the problem and if there is some reference to this problem such as if it is well known its used, once I read that this have a chaotic behavior, and also read It was used in probability but don't remember where I got that information. So if you know something I would be grateful to be notice, thanks in advance. Better Information On Defense Damage Clash of Clans The way that Clash of Clans chooses to convey information about how much damage defense buildings output is bad. The current method of telling the user that a mortar does X dmg a second is pretty worthless since they fire much slower than once a second.  Where can I find a break down / what is the damage break down for how much damage these buildings do per shot rather than per second?  Sure, information on each level of the buildings would be nice but if that is too much I think simply providing the data for level one of each building would also work. In eevee, shadows are clipped by camera distance As shown in the gif, the shadow in eevee is clipped by the camera distance. The same is true for F12 rendering. Where are the options to improve this issue? How can I reduce the ever-increasing time to push a subtree? If someone else is booking international ticket for me using his credit or debit card, does he need to be present physically at the time of check-in?   Suppose I am coming back from Singapore to my home country and my ticket is booked by my friend for me, who lives in my home country. Do airlines in Singapore ask for the person to be present physically to check in?