4:09 AM
1

I am trying to find a smooth and differentiable function, which converges to the characteristic function $\mathbf{1}_{[a,b]}$. Is there an easy idea how to realise that? I suppose it should look like this  f_n(x)= \left\{ \begin{array}{ll} 1 & x \in [a,b] \\ 1-n(x-b) & \, x\in [b,(1/n)+b] \\ n(...

3 hours later…
7:11 AM
Since the question was bumped, I have edited the tags, too. But further improvements to the choice of the tags are more than welcome: Can you find a domain where $ax+by=1$ has a solution for all $a$ and $b$ relatively prime, but which is not a PID?
17

In Intro Number Theory a key lemma is that if $a$ and $b$ are relatively prime integers, then there exist integers $x$ and $y$ such that $ax+by=1$. In a more advanced course instead you would use the theorem that the integers are a PID, i.e. that all ideals are principal. Then the old lemma can...

6 hours later…
1:05 PM
-4

I would like to propose a new tag: Math art. In my browsing I have found some questions like this 1 , 2 etc whose point is to create art from mathematical expressions. I think encouraging such questions and creating said tag would add another positive dimension to the site. What do you people thi...

1:16 PM
For some time there was a tag called - of course, that's a bit different from this proposal.
11

art, really? What is it good for? Do we really need it?

As you can see, there were 15 questions tagged in January 2015: chat.stackexchange.com/transcript/3740/2015/1/17
in Math Mods' Office, Jan 24, 2015 at 8:01, by Arthur Fischer
As for (art), I actually think it could be a viable tag, although currently it's probably used in too many disparate contexts to make it worthwhile. I actually had thought to post something to that request a little while ago, but got sidetracked.
Jan 25, 2015 at 9:04, by Martin Sleziak
@MartinSleziak I see that removal of has already started.
Posts where the tag was added/removed (including the editors): data.stackexchange.com/math/query/1105163/… data.stackexchange.com/math/query/1038474/…

4 hours later…
5:16 PM
I remain neutral on the idea of an art-focused tag, but I definitely don't see any reason to call it "math-art". Everything on this site is about mathematics, so the name feels redundant. art would likely be more appropriate (assuming that the community sees value in such a tag). — Xander Henderson ♦ 1 hour ago
Oh, and look! The tag already exists! — Xander Henderson ♦ 1 hour ago
Oh! The tag actually exists. I thought that it was removed - following Asaf Karagila's post linked above.
Removal of the tag (art) was actually suggested back in 2015. (And the suggestion gained some support at the time.) — Martin Sleziak 23 secs ago