Make axis intersection look nice with tikz and pgfplots
How to get rid of notch at pgfplots axes intersection?
Please don't refer to 2019 as 'a great year' Iterated self-composition of arbitrary function Does there exist some notation that represents the iterative composition of a single-input, single-output function with itself? As in, say, $f_5(x)=f(f(f(f(f(x)))))$.  In other words, going by the above (incorrect, I'm pretty sure) notation:  $f(x)=x+1$, $f_n(m)=m+n$  I'm looking for the correct way to express the notion of "$f_n(x)$" for any $f$. Proof that in a field $x=0$ is equivalent to $x=-x$ Reset Windows 10 from USB I have a Windows machine (laptop) that needs fixing. The current installation is really badly broken (e.g. the taskbar is unresponsive, but the Explorer windows work, booting takes literally half an hour) and when I try to access the settings app and click on the tile to access the reset settings it instantly crashes. The same happens in Safe Mode.  I have created a USB install medium using the tool offered by Windows on my own Windows desktop machine. I've ensured that both the laptop and the USB tool have the same version of Windows (Home, 64-bit, NL). When I want to reinstall Windows on the laptop with this stick I am asked to enter a serial number which I obviously don't have. I don't want to try and see if I can phone activate it, because if it fails the install is gone.  I need to reinstall this Windows machine from a USB stick. There are a few problems I can't find an immediate solution for on the .   If I use a tool such as  to extract the serial number, will this work? If the above does not work, how can I reinstall this Windows machine? Inequality from Challenge and Thrill of Pre-college Mathematics How do I run specific sudo commands without a password? On one particular machine I often need to run sudo commands every now and then. I am fine with entering password on sudo in most of the cases.  However there are three sudo commands I want to run without entering password:   sudo reboot sudo shutdown -r now sudo shutdown -P now   How can I exclude these commands from password protection to sudo? I know only the very basics of TikZ, having only used it to produce a pretty flow chart for one of my documents. I recently learned that you can use Inkscape and export to TikZ.  What are the limitations of the Inkscape->TikZ workflow? Is there some compelling reason to take the time to learn TikZ (which I'm told has a fairly steep learning curve) rather than simply exporting to TikZ from Inkscape? How to make partitions mount at startup? How do you make HDDs and partitions mount at startup on Ubuntu?  I always keep my media and data files on separate partitions - one 2tb HDD and a 400 odd gig partition.  I have been trying to swap the default folder location for the home directory to my other drives.  It works when I change the /home/user_name/.config/user-dirs.dirs file to the directories I want, but only until I reboot the system. I am only assuming that the drives not mounting is the problem with it, but it would be helpful either way.  If any one knows another reason for why the directories change back to default each time that would be good also. How to I stop a launchd script from running on wake I have a simple launchd script that plays a sound every 30 minutes and it runs out of the user library ~/Library . It doesn't run if my machine is asleep, but does run the last event missed when the machine wakes. I think this is the expected behavior. My question is, how do I stop this happening. If I missed the half-hour event, I don't want it to be run at 20 minutes past the hour.  Here's the core of my script. It calls a Python script. I tried to put a block in the python script to check that I am within a few minutes of each 30 minutes, but that doesn't seem to work on wake. (Is it missing the system clock somehow?)  &lt;key&gt;ProgramArguments&lt;/key&gt; &lt;array&gt;     &lt;string&gt;/usr/local/bin/python3&lt;/string&gt;     &lt;string&gt;/Users/pheon/Documents/playsound.py&lt;/string&gt; &lt;/array&gt;  &lt;key&gt;StartCalendarInterval&lt;/key&gt; &lt;array&gt;     &lt;dict&gt;         &lt;key&gt;Minute&lt;/key&gt;         &lt;integer&gt;0&lt;/integer&gt;     &lt;dict&gt;         &lt;key&gt;Minute&lt;/key&gt;         &lt;integer&gt;30&lt;/integer&gt;     &lt;/dict&gt; &lt;/array&gt;   Here is a snippet from the python code which checks the time before playing the sound.  time0 = datetime.datetime.now() if (time0.minute % 30) &lt; 2:     subprocess.run(["/Users/pheon/bin/afplay-vol.sh", "1", bell],check=True) Tags on badge question list I'm trying to get the Weed-Eater hat on Stack Overflow. To do so, I'm looking at the list of questions . The problem is, no tags show up there, and so it's rather difficult to see which ones I have a shot at. Any chance of showing the tags on this page?  I realize that getting this before Winter Bash is over would be difficult, but it would be good to keep such things in mind for the future. Where can the viewport clipping parameters be changed? To put it simple, there's a simple java swing app that consists of JFrame with some components in it. One of the components is a JPanel that is meant to be replaced by another JPanel on user action.  So, what's the correct way of doing such a thing? I've tried  panel = new CustomJPanelWithComponentsOnIt(); parentFrameJPanelBelongsTo.pack();   but this won't work. What would you suggest? Evaluating limit (iterated sine function) The limit is   $$\lim_{x\rightarrow0} \frac{x-\sin_n(x)}{x^3},$$  where $\sin_n(x)$ is the $\sin(x)$ function composed with itself $n$ times:  $$\sin_n(x) = \sin(\sin(\dots \sin(x)))$$  For $n=1$ the limit is $\frac{1}{6}$, $n=2$, the limit is $\frac{1}{3}$ and so on.  Can we define a recurrent relation upon that given hypothesis? Also, how do I involve $n$ into calculation, because the final limit will depend on it?  Any suggestions on how to tackle this?  Thank you! Command for creating a directory and navigating into it directly? How to keep the spaces at the end and/or at the beginning of a String? I've been wondering about this one for a while; I find it a little weird how abruptly it happens. Basically, why do we need just three uniforms for $Z_n$ to smooth out like it does? And why does the smoothing-out happen so relatively quickly?  $Z_2$:     $Z_3$:    (images shamelessly stolen from John D. Cook's blog: )  Why doesn't it take, say, four uniforms? Or five? Or...? How can I get query string values in JavaScript? I am asked to solve this ODE: $$yy''-y'y^2-(y')^2=0.$$ Can I get some guidelines on how I can solve it? I am not sure how to approach without initial conditions. Let $f(x) = x^2 \sin{\frac{1}{x}}$ for $x\neq 0$ and $f(0) =0$. (a) Use the basic properties of the derivative, and the Chain Rule to show that $f$ is differentiable at each $a\neq 0$ and calculate $f'(a)$. You may use without proof that $\sin$ is differentiable and that $\sin' =\cos$.  Not even sure what this is asking.  (b) Show that $f$ is differentiable at $0$ and that $f'(0) =0$.  $\frac {f(x)-f(0)}{x-0} \to \lim_{x \to 0} x \sin(1/x)$. $x \sin(1/x) \leq |x|$ and $\lim_{x \to 0} |x|=0$. Thus $f(x)$ is differentiable at $0$; moreover $f^{'}(0)=0$.  (c) Show that $f'$ is not continuous at $0$.  $f{'}(x)=x^{2} \cos(1/x) (-x^{-2}) + 2x \sin (1/x)$. In pieces: $\lim_{x \to 0} \cos (1/x)$. $f^{'}(0-)$ nor $f{'}(0+)$ exists as $x \to 0$ $f^{'}(x)$ oscillates infinity between $-1$ and $1$ with ever increase frequency as $x \rightarrow 0$ for any $p&gt;0$ $[-p,0]$, $[-p,p]$ or $[0,p]$ $f$ is not continuous. Question: How to show more rigorously? In theory, is it possible that the loss on the train set will increase together with the train set accuracy? (in the normal case the train set loss should go down) And vice versa, can the train loss decrease along with the accuracy?   Note: This is obviously different than the classic underfit / overfit cases which are easier to grasp.