Does anyone know how I can download mac os 11.3 to an external USB seems like the most basic thing but I can't find out how every time I google it I just get articles about making a bootable USB which isn't what I'm interested it.
Sometimes it's hard to search for older versions of macOS &amp; OS X  on the App Store.  This is an attempt to provide the canonical QA for this issue, as per the Meta QA -  I expect it to be modified over time to hopefully become a complete information resource.  How can I get any older version of a Mac OS to be able to run as a VM, or to reinstall on my Mac?
Help resizing posted images I often add pictures to my questions. Most of the time they come out the right size. Well, that used to be OK always, up until I started posting screenshots taken by my mobile. For example, this one:  This way, I'm sure you'll agree it is huge, decidedly too big, it takes up the whole body of the question, I mean. At present, the only way I have to resize it is the following code: &lt;sub&gt;(Click image to enlarge)&lt;/sub&gt;  [&lt;img src=&quot;http://i.stack.imgur.com/hKmRp.jpg&quot; width=&quot;210&quot; height=&quot;350&quot; alt=&quot;&quot;&gt;][1]  which I do not remember, and always have to recover from . Is there a simpler, less HTML-hacky (and, I'd expect, more Markdown-based) way of resizing it? PS The output of the above code is: (Click image to enlarge) I'm trying to install the flashybrid but when I enter the apt-get install flashybrid command, I get this error:  root@user-desktop:/home/user# apt-get install flashybrid Reading package lists... Done Building dependency tree Reading state information... Done flashybrid is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 1 not fully installed or removed. After this operation, 0B of additional disk space will be used. debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable Setting up flashybrid (0.15+nmu2) ... debconf: DbDriver "config": /var/cache/debconf/config.dat is locked by another process: Resource temporarily unavailable dpkg: error processing flashybrid (--configure): subprocess post-installation script returned error exit status 1 Errors were encountered while processing: flashybrid E: Sub-process /usr/bin/dpkg returned an error code (1)   I also tried this one to find what is already using that file:  root@user-desktop:/home/user# lsof | grep /var/cache/debconf/config.dat lsof: WARNING: can't stat() fuse.gvfs-fuse-daemon file system /home/user/.gvfs Output information may be incomplete. dpkg-prec 4672 root 4rW REG 8,6 39658 1697827 /var/cache/debconf/config.dat   But I don't know how to fix this. For which values of $\alpha$ and $\beta$ does the integral $\int\limits_2^{\infty}\frac{dx}{x^{\alpha}\ln^{\beta}x}$ converge? Find and extract a number from a string Redundant prepositions? This is a tooltip in an application:     Identifies the site name to which the GL code belongs to.   Can I say that it is incorrect to use "to" twice here and we should remove 1 of them?  Other examples:       Identifies the vendor to which the port speed is associated with.   Provides the vendor to which the milestone is associated with.   (They are both tooltips, too)  The repetitions here are incorrect, aren't they? Please confirm. How to render lightning in Cycles How can you render a lightning bolt using Cycles? What is $i^i$ and $(i^i)^i$ What is $i^i$ and $(i^i)^i$. I fond some answers  but is there a clearer explanation of this? Maybe something help me to understand. Let $p\in[1,\infty]$, $a\in\ell^\infty$ and $$T:\ell^p\to\ell^p\;,\;\;\;x\mapsto ax.$$ Note that $\left\|T\right\|=\left\|a\right\|_{\ell^\infty}$. It's easy to see that if $a\in\ell^1$, then $T$ is nuclear and hence compact.  Can we more generally conclude that $T$ is compact?  Assume $p&lt;\infty$. The intuitive approach would be to define $$T_n:\ell^p\to\ell^p\;,\;\;\;x\mapsto(a_1x_1,\ldots,a_nx_n,0,\ldots)$$ for $n\in\mathbb N$ and to show that $\left\|T_n-T\right\|\to0$. Now, $$\left\|(T_n-T)x\right\|^p=\sum_{i=n+1}^\infty|a_ix_i|^p\tag1$$ for all $x\in\ell^p$ and $n\in\mathbb N$. The right-hand side of $(1)$ clearly converges to $0$ as $n\to\infty$, but this only yields convergence in the strong operator topology. On the other hand, if $(a_n)_{n\in\mathbb N}$ would be nonincreasing and $a_n\to0$ (e.g. $a_n=\frac1n$), then $$\left\|(T_n-T)x\right\|^p\le|a_{n+1}|^p\left\|x\right\|_{\ell^p}^p\tag2$$ for all $x\in\ell^p$ and $n\in\mathbb N$ and we could immediately conclude $\left\|T_n-T\right\|\to0$. EDIT: Maybe the general result can be obtained from the convergence in strong operator topology (which holds by $(1)$) by noting that $\ell^p$ has the approximation property; but I'm not sure whether this is true. In PHP, what does the ${$ } syntax do? Install MS Truetype Fonts system-wide for all users I would like to install the MS Truetype Fonts that come through the package ttf-mscorefonts-installer, so I did:  sudo apt-get install ttf-mscorefonts-installer   Accepting the license, the process completes without any errors. The fonts end up in     /usr/share/fonts/truetype/msttcorefonts   as expected. Just to be sure, I also did a  sudo fc-cache -f -s -v   which among other things says in its output:     /usr/share/fonts/truetype/msttcorefonts: caching, new cache contents: 60 fonts, 0 dirs   So far, so good (and inline with question ) However, when I then open any font dialog (e.g. in OpenOffice or the font dialog of the terminal) I don't see all of the new fonts. For Arial, the standard form is missing, but bold and italic are there. Times New Roman is missing altogether.  I can use nautilus to browse to the font directory, double click the Arial.ttf file and see the font in all its beauty. I can even click the install button then and the font is copied over to my personal ./fonts directory and from there on visible to my apps. But it is not picked up from the system directory.  How do I get these fonts available system-wide for all users? Using congruences, show $\frac{1}{5}n^5 + \frac{1}{3}n^3 + \frac{7}{15}n$ is integer for every $n$ How can I change wallpaper automatically? I have found a guide for that but doesn't sure if it will work or it is safe to use. The guide:  I am asking if is these introductions safe and will work? If not, is there any other solutions for that? I am using Ubuntu 20.04 LTS Thank you. Get selected value in dropdown list using JavaScript When deriving the quadratic equation as shown in the  () the main proof contains the step: $$ \left(x+{\frac {b}{2a}}\right)^{2}={\frac {b^{2}-4ac}{4a^{2}}} $$ the square root is taken from both sides, so why is  $$\sqrt{4a^2} = 2a$$  in the denominator and not $$ \sqrt{4a^2} = 2\left |a  \right | $$ Could somebody explain this to me? Thank you very much Why is disk usage greater than the size of all files on it? fsck error on boot: /dev/sda6: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY Create a tar archive split into blocks of a maximum size I need to backup a fairly large directory, but I am limited by the size of individual files. I'd like to essentially create a tar.(gz|bz2) archive which is split into 200MB maximum archives. Clonezilla does something similar to this by splitting image backups named like so:  sda1.backup.tar.gz.aa sda1.backup.tar.gz.ab sda1.backup.tar.gz.ac   Is there a way I can do this in one command? I understand how to use the split command, but I'd like to not have to create one giant archive, then split it into smaller archives, as this would double the disk space I'd need in order to initially create the archive. How to select a value from a list with non-uniform probabilities? Why can't I use a type argument in a type parameter with multiple bounds? So, I understand that the following doesn't work, but why doesn't it work?  interface Adapter&lt;E&gt; {}  class Adaptulator&lt;I&gt; {     &lt;E, A extends I &amp; Adapter&lt;E&gt;&gt; void add(Class&lt;E&gt; extl, Class&lt;A&gt; intl) {         addAdapterFactory(new AdapterFactory&lt;E, A&gt;(extl, intl));     } }   The add() method gives me a compile error, "Cannot specify any additional bound Adapter&lt;E&gt; when first bound is a type parameter" (in Eclipse), or "Type parameter cannot be followed by other bounds" (in IDEA), take your pick.  Clearly you're just Not Allowed to use the type parameter I there, before the &amp;, and that's that. (And before you ask, it doesn't work if you switch 'em, because there's no guarantee that I isn't a concrete class.) But why not? I've looked through Angelika Langer's FAQ and can't find an answer.  Generally when some generics limitation seems arbitrary, it's because you've created a situation where the type system can't actually enforce correctness. But I don't see what case would break what I'm trying to do here. I'd say maybe it has something to do with method dispatch after type erasure, but there's only one add() method, so it's not like there's any ambiguity...  Can someone demonstrate the problem for me? $X$ is homeomorphic to $X\times X$ (TIFR GS $2014$) Question is :  Suppose $X$ is a topological space of infinite cardinality which is homeomorphic to $X\times X$. Then which of the following is true:   $X$ is not connected. $X$ is not compact $X$ is not homeomorphic to a subset of $\mathbb{R}$ None of the above.   I guess first two options are false.  We do have possibility that product of two connected spaces is connected.  So, $X\times X$ is connected if $X$ is connected. So I guess there is no problem.  We do have possibility that product of two compact spaces is compact.  So, $X\times X$ is compact if $X$ is compact. So I guess there is no problem.  I understand that this is not the proof to exclude first two options but I guess the chance is more for them to be false.  So, only thing I have problem with is third option.  I could do nothing for that third option..  I would be thankful if some one can help me out to clear this.  Thank you :)