Cannot copy/cut and paste from file manager to Desktop on Ubuntu 20.04 LTS
Basic desktop actions are not available on Ubuntu 20.04
Detect browser language in Rails Why is $\sqrt{-x}*\sqrt{-x}=-x?$ Why are my fields initialized to null or to the default value of zero when I've declared and initialized them in my class' constructor? Best practice for Rails App to run a long task in the background? how to disable system apps without root? How to disable system apps without root?  My phone model is vivo x5 max+ and android 4.4.4  I have tried Debloater but it failed to connect (I am sure I've allowed USB debugging). Does the intersection of two finite index subgroups have finite index? How can one differentiate between "who" and "whom"? Many times, I've been asked the difference between "who" and "whom". I myself know the difference, but it is hard to explain to others. What is the easiest way to explain it to those with a basic understanding of English? A mnemonic (if possible) would help. reformat date to have month in words Currently my text file looks like this..  David   Webb    Box 34 Rural Route 2    Nixa    MO  65714   (417)555-1478   555-66-7788 09-13-1970 Martha  Kent    1122 North Hwy 5    Smallville  KS  66789   (785)555-2322   343-55-8845 04-17-1965 Edward  Nygma   443 W. Broadway Gotham City NJ  12458   (212)743-3537   785-48-5524 08-08-1987 O'Reilly    Baba    123 Torch Ln    Joplin  MO  64801   (417)222-1234   456-65-3211 12-13-1999 Martin Bob  44 Boss Rd  Joplin  MO  64801   (417)888-4565   456-98-1111 01-01-2007   the dates are in the 9th field and I want to display them as January 7, 2017 instead of 01-07-2017 for example.  How should I do that? If using options please explain what they do briefly. Doing this in bash. Needing to put it in a script and output to a new file to preserve original. $\|u\|\leq \|u+av\| \Longrightarrow \langle u,v\rangle=0$ Prove that $\langle u,v\rangle=0\Longleftrightarrow \|u\|\leq \|u+av\|$.  So far I can get the $\Longrightarrow$ very easily, but I need some help with the $\Longleftarrow$ implication, any hints would be greatly appreciated.  Please no answers, I just want a small nudge to get me in the right direction, I've been stumped on this for a little bit.  Here's what I have so far:  ($\Longleftarrow$)  Assume $\|u\| \leq \|u+av\|$  $\|u+av\|^2=\langle u+av,u+av\rangle=\langle u,u\rangle+ \langle u,av\rangle+\langle av,u\rangle+\langle v,v\rangle=\|u\|^2+\bar{a} \langle u,v\rangle+a\langle v,u\rangle+\|v\|^2=\|u\|^2+ \bar{a}\bar{\langle v,u\rangle}+a\langle v,u\rangle+\|v\|^2$  Thoughts/ideas? Are there rules for falling in water vs. diving vs. just jumping in for various depths of water? Using conjugates to find a limit with a cubic root: $\lim_{h\to 0}\frac{\sqrt[3]{h+1}-1}{h}$ I currently have $$\lim_{h\to 0}\frac{\sqrt[3]{h+1}-1}{h}$$  Now, I know that when you have square root instead of a cubic root it's easy. You just multiply by the conjugate and simplify afterwards. If it were a sqrt I know that the limit is 1/2. I know that the result here is 1/3 but I can't seem to get there. I always end up with 1/4 due to getting something like: $$\frac{h+1-1}{h(\sqrt[3]{h+1}+1)(\sqrt[3]{h+1}+1)}$$  After simplifying and evaluating the limit you end up with $$\frac{1}{(\sqrt[3]{0+1}+1)(\sqrt[3]{0+1}+1)}$$  which turns out to be $1/4$.  What am I doing wrong? How can I form a word like "quadruple" for any number I want? I'm not sure what these are called, but how can I form a word like "quadruple" for any number I want? Like 5× as much is quintuple, what is 31× as much or 147× as much? I want to know how they are formed so I can make my own.  Similarly, how do I construct the prefixes, such as unicycle, bicycle, tricycle, quadricycle? I figured out 12 is duodeci-, but how can I form any prefix like this? PostgreSQL check bloating of a table Bounty-like facility for rewarding excellent questions Amongst the reasons for starting a bounty, one can select:     Reward existing answer      One or more of the answers is exemplary and worthy of an additional bounty.   Why not enable one to reward excellent questions in a similar manner? If $f(x)=x-\int^{\frac{\pi}{2}}_0f(x)\sin(x)dx$ find the explicit function for $f(x)$ in its simplest form How can I disable the hot corner /Activities corner using the Terminal? How can I disable the hot corner /Activities corner using the Terminal?  I know I can use the Tweak Tool, as mentioned , but I am writing a little bash script to reconfigure my Ubuntu Gnome quickly to my needs so I would like to use e.g. gsettings for that. Why I can't scan the WhatsApp QR? Best method for short time-series We all know that the amount of current flowing b/w the plates is independent of the frequency. If I were to ask why doesn't it depend then you'd probably say that it depends on the number of electrons rather than the frequency or you might show me a current vs frequency graph.  But here is my theoretical argument. Electric current is defined as the amount of charge flowing through a point/space/wire per unit time. Let I be current due to photo electrons ejected by photons of some frequency. Now if I would increase the frequency, the kinetic energy of the ejected electron would increases, therefore it will move faster and therefore contribute more current (charge will through the same point many times per unit time) . Thereby, giving a net current greater than I.  What is wrong with my argument?  After thinking a lot, I came up with a possible reason. However fast the electrons may move, but when they hit the metal plate, they would lose their velocity and start moving in drift velocity. Now there is a problem with this argument. If this were to be true then I should expect to see a big chunk of extra electrons getting stuck at the anode.  If my reasoning was correct, then why can't I see a big charge buildup at the anode. Find the point which is furthest away from existing points while remaining within the convex hull