Word for "something that is required but cannot be achieved"?
Word for a task which is flawed or doomed to failure but which you have to do anyway?
Which is the simplest way to update a Label from another Thread?   I have a Form running on thread1, and from that I'm starting another thread (thread2).  While thread2 is processing some files I would like to update a Label on the Form with the current status of thread2's work.   How could I do that? Given the function: $$f(x) = \begin{cases} x\cdot\sin(\frac{1}{x}) &amp; \text{if $x\ne0$} \\ 0 &amp; \text{if $x=0$} \end{cases}$$  Question 1: Is $f(x)$ continuous at $x=0$?  Question 2: What is the derivative of $f(x)$ at $x=0$ and how do I calculate it? Is there a rule of thumb for objective questions asked out of curiosity? Isaac Moses, the patriarch of Mi Yodeya, :  [...] the general Stack Exchange directive, expressed in the uneditable part of that section of the About page, to &quot;Focus on questions about an actual problem you have faced. Include details about what you have tried and exactly what you are trying to do.&quot; In fact, while this directive is perfect for the behemoth programming site that Stack Exchange grew out of, it doesn't fit very well for any of the more intellectually-oriented, rather than practically-oriented sites. [...]  This is something that's bugged me for a while, and ended up prompting a discussion between Anna, Aarthi and me. The gist of it: is there any simple test that can be used to identify answerable questions asked in good faith when the &quot;problem to be solved&quot; is... simple curiosity? Obviously, this is something that sites like  and  have had to contend with for some time, but now and then such questions pop up even on sites where folks are generally trying to solve real problems. While a potentially interesting thought experiment, . Strictly-speaking, problems like that fail the  test. And yet, I would keep that question simply because I learned something useful from the answers − not necessarily something I would ever apply to socks mind you, but certainly something I might apply to similar problems. I don't believe the question was asked in bad faith or for mindless social fun; yet, I have a bit of trouble stretching the definition of &quot;based on actual problems&quot; to contain it. Obviously, the fact that we're hosting a growing number of sites dedicated mostly or entirely to intellectual curiosity makes this something of a rhetorical question. The &quot;actual problems&quot; part of the FAQ was added specifically to draw a line between good and bad  − heading off  and their ilk. But it's a pretty damn good litmus test, and if it's ok to ignore it for some questions − or particularly for  − then what should stand in its place? Uninstalling Ubuntu from Windows Dual Boot if I don't have Windows recovery CD I installed Ubuntu (I had already had Windows 8.1) from USB (I still have live Ubuntu on it). Is there a way I can uninstall Ubuntu in a way that my Windows will remain bootable? All the tutorials I have seen say that uninstalling ubuntu will delete GRUB also so I will need a Windows recovery CD to boot into it, but I don't have one. Is there a solution? I have 238gb of timelapse photos which was taken over a period of twenty days and all the photos are split up into 20 folders. I would like to put this together into a timelapse, I tried using Premiere Pro but that is taking very very long, any tips on putting it together fast btw Im on a Mac, thanks. Can I create a Controller that simply returns an image asset?  I would like to route this logic through a controller, whenever a URL such as the following is requested:  www.mywebsite.com/resource/image/topbanner   The controller will look up topbanner.png and send that image directly back to the client.  I've seen examples of this where you have to create a View - I don't want to use a View. I want to do it all with just the Controller.  Is this possible? Finding my house in minecraft How can I assign the output of a command to a shell variable? gdal_translate- why jpg compressed tif is 2 times greater than jpg file? TL2018 (MacTeX) and TikZ calligraphy library Show that a ring is commutative if it has the property that ab = ca implies b = c when $a\neq 0$ Show that a ring is commutative if it has the property that ab = ca implies b = c when $a\neq 0$.   This is my proof to show that a ring is commutative if it has the property that ab = ca implies b = c.  We need to show that if x, y ∈ R then xy = yx. Let a = x, b = yx and c = xy. Then ab = x(yx) = (xy)x = ca. Thus, by the hypothesis, b = c, or xy = yx. Thus, for x, y ∈ R we have xy = yx.   How would I show when $a\neq 0$? How could they return the Infinity Stones in their "raw" form? There is this one little thing that I don't quite get at the end of Avengers: Endgame.  After Thanos was defeated, Captain took the stones back to where they were originally taken to "correct" the timeline. However we see that Cap has the 6 stones in their "Raw" form, but that is not how all of them were taken.   For example in 1970 Tony didn't take the Space Stone but the Tesseract, so I assume they extracted the Space Stone in the present (by breaking the Tesseract like Thanos in the Infinity War movie?).   So how could Cap return the stone to the rightful place when he actually needed to return the Tesseract? Or am I missing something here...   The same goes for the Mind Stone, which was inside the Gem on the Staff Loki had in the first Avengers movie. Limited options in a certain area? Ok so i am a bit of a noob in blender, so I need help with this.  I am trying to texture something, but there is no texture button where there should be, because the blender edge window cuts it off here's a picture Where do I ask where to ask? If I have a specific question I want to ask about, but I don't know which Stack Exchange site would be on topic for asking that question, where can I ask where to ask that question?  Is there any generic place where we can ask for advice? Is it here?  This is not about a specific question but in general.  For example: "Where should I ask for advice about fishing?", or if I need to know where I should ask "What would be the best fishing rod to fish for salmon?" (regardless of how good/bad these examples are) Zero morphism does not depend on zero object I want to prove that zero morphism does not depend on zero object. Let a zero object $0 \in \mathcal{C}$.  I supposed that exists another zero object $0' \in \mathcal{C}$, and I considered $0: A \to B$ and also $$A \to 0 \to 0' \to B$$ But I don't know to prove that zero morphism $0: A \to B$ not does not depend on zero object. Can anybody give me a suggestion? Compute $\lim_{x\to\infty}x\;\left[\left(1+\frac{1}{x}\right)^x-e\right]$ How can I compute the following limit, and is there a general method to resolve problems of this type?  $$\lim_{x\to\infty}x\left[\left(1+\frac{1}{x}\right)^x-e\right]$$ How can a structure have infinite length and infinite surface area, but have finite volume? Find the subgroups of A4 I had a question I was hoping for some help on:     Find all of the subgroups of $A_4$   Here is what I know:  $A_4$ is the alternating group on 4 letters. That is it is the set of all even permutations. The elements are:  $(1), (12)(34), (13)(24), (14)(23), (123), (132), (124), (142), (134), (143), (234), (243)$   which totals to 12 elements. Which means, the subgroups should have order 1,2,3,4,6 and 12. The groups of order 1 and order 12 are trivial. I also know the groups of order 2 which are:  $[1,(12)(34)], [1, (13)(24)], [1, (14)(23)]$  but would someone be able to help me find the subgroups of order 3, 4 and 6 and be able to provide a good, easy explanation of how you got to them for me? I'm pretty sure there is no such groups of order 6, but I don't know how to explain why.  Thank you so much for your help in advance, I really appreciate it! Number of moves necessary to solve Rubik's cube by pure chance Suppose, random moves are made to solve Rubik's cube. A move consists of a $90$-degree-rotation of some side. The starting position is also random.   What is $E(X)$, where $X$ is the number of moves until the cube is solved ? How many moves must be made, that the probability that the cube is solved, exceeds $99$% ? What is the best way to iterate over a dictionary?