CURED - 2018-01-22

David Reed

12:13 AM

@XanderHenderson Currently flying over south America. Good memory ;)

amWhy

12:36 AM

Get ready: Perhaps will be in need in delete votes soon, @Did, @ZacharySelk, @SimplyBeautifulArt, @user21820

user21820

2:37 AM

@Did @amWhy @ZacharySelk: PSQ here open for deletion.

amWhy

@user21820 o/

user21820

@amWhy Sorry I need to go off now. Was just dropping in haha..

amWhy

@user21820 no problem. See in in a handful of hours!

user21820

Yup.

SmokeDetector

6:20 AM

[ SmokeDetector | MS ] Username similar to website in answer: Intuitive explanation of binomial coefficient by charleslow on math.SE

D.Hutchinson

6:38 AM

welcome back @amWhy :)

The Great Duck

I would ignore smoke detector as github is a file sharing service. There it is almost always assumed that a link to github is a link to ones personal github.

at least from my experience

1

Q: Are functions converging to the same value locally equivalent?

Suppose we have two functions $g(x)$ and $f(x)$ such that $\lim_{x \to 1} g(x) = \lim_{x \to 1} f(x)$. Definition: For any function $f$ we define the continuous sequence from $a$ to $b$ to be the function $g(x) = f(ax + b(1-x))$ where $g$ is defined on the range $[0,1)$. Does there necessar...

I edited and added the broader definition from my paper

Professor Vector

7:36 AM

@quid Yes, sure. But it's not a coincidence that's referring to the help center instead of quoting: that definition is long-winded and vague. And I was referring to a more specific case: we can't have x^{1/\infty}=1, because that would mean x=1^\infty. As I wrote, that's a fallacy, but a mathematical one, so it's better to address it, instead of "close and forget".

Martin Sleziak

7:49 AM

@ProfessorVector I will add that there is a feature-request asking for change off-topic/missing context (basically to a separate close reason) - it is currently at +15: A feature requested for the purpose of avoiding unintentional newbie-biting

I am posting this as a follow-up to the @quid's explanation how off-topic/missing-context works at the moment.

Admittedly, from the title of that post on meta, it would be quite difficult to guess what that feature request is about.

Professor Vector

Oh yes, you can say that, indeed. But I support it. We should always try to say exactly what we mean (ok, within reason, to avoid moderator warnings for "rude";-).

The Great Duck

I think lacking context is a poor reason

many great questions have no context

i think it should be rephrased as an expression of level of knowledge/rigor

because obviously if one asks a question about a why a stmbol looks a certain way they shouldnt need any context. it is obviously one borne purely from curiosity

similarly context only matters for questions attempting to "solve" something

so context reallt sounds weird as if we expect everyoe to post a statement on why they are asking, when really that isnt useful most of the time and can cause more confusion when the use for the math is something sufficiently complicated to explain to a math forum.

Professor Vector

8:12 AM

@TheGreatDuck You're right only in some cases. Two examples: somebody asks for a solution of a Diophantine equation. "Own effort?" "Hey, I'm only ten years old" But he's curious, and just might understand the answer. Not a chance, on hold, indefinitely, I guess. Another guy constantly asks questions just by throwing together unrelated concepts, never showing own effort, always evades questions like "What for?", never on hold.

Martin Sleziak

Since you've been around for some time, I am pretty sure that you are aware that including context is not the same thing as showing your own effort.

Some relevant posts on meta: Can we stop the “Show your work craze”? and How to ask a good question - Provide Context.

And, as a side note, Stack Exchange users are supposed to be at least 13 - for some legal reasons, which I am not really interseted in: How do I use Stack Exchange if I'm under 13 years old?

Professor Vector

@MartinSleziak Well, I'm around for a few months (9 or so). But "I'm ten years old" would be context, for instance. I'm not much interested in the legal reasons, either. The site may be dangerous, but not for that.

The Great Duck

8:27 AM

@MartinSleziak it was just an example. but technically COPPA falls more on the scope of the internet let alone SE.

user21820

9:42 AM

@TheGreatDuck I like it when someone asks a question and says, "I was just curious because I read X and wondered Y." In my opinion, that explanation of the curiosity is more than sufficient context.

@ProfessorVector If you have any examples of either case, post here and we can discuss and see what to do about it. =)

user21820

10:25 AM

@Did @amWhy @ZacharySelk @XanderHenderson @SimplyBeautifulArt: All of the questions by this user so far are PSQs, and note that the most recent two are identical except for the mathematical formula!

And this total PSQ is still open...

Professor Vector

10:59 AM

@user21820 The young aficionado of Diophantine equations is here, the other case I mentioned is probably not worth our time. Concerning that last PSQ: that guy has more than 3k for upvoted questions, and what are you proposing to do with a question having an accepted answer? Closing it would hardly impress that person, nor people upvoting such questions.

user21820

@DanielFischer: Hello! Just saw you pop in.

@ProfessorVector I don't agree that it's a good question, but not necessarily that the asker purposely made a bad question. What is missing is the name of the olympiad, and an answer to Stephen Meskin's comment.

Martin Sleziak

11:34 AM

BTW if you look at the timeline of that question you can see that it has already been in the reopen votes review queue twice: math.stackexchange.com/review/reopen/933432 and math.stackexchange.com/review/reopen/936836

Professor Vector

@user21820 I don't think Stephen Meskin would want my answer to his comment: the main problem is not to find the only positive solution, but to show that no other positive solution can exist.

user21820

@ProfessorVector But you aren't the one Stephen is talking to. The whole point of the comment is to get the asker to try something. One can never learn how to solve this kind of problem if one never even lifts a few mental fingers to try small cases.

@MartinSleziak Interesting, thanks!

Martin Sleziak

11:52 AM

BTW there are a few older questions about the same problem. This one is open: Determining all the positive integers $n$ such that $n^4+n^3+n^2+n+1$ is a perfect square.

And these two are closed: Formula for calculating the total number of solution pairs to an equation and $y^2 = \frac{x^5 - 1}{x-1}$ & $x,y \in \mathbb{Z}$.

Professor Vector

@user21820 In principle, I agree, very much so: I can't help a smile when OPs report a struggle with a problem, but (almost) never show a battlefield drenched in blood, sweat and tears, so it's more likely to assume that they just tried to stare it down for the better part of 2 minutes, and asked their question, then. But x^2-61y^2=1 has infinitely many solutions, the smallest being (1766319049, 226153980), so... no small examples, there.

Martin Sleziak

I certainly have no problem with reopening and then closing as a duplicate - if you think that this is a reasonable direction to take (and somewhat kinder for the first interaction of a new user with the site).

There are a few older posts about this: Determining all the positive integers $n$ such that $n^4+n^3+n^2+n+1$ is a perfect square, Formula for calculating the total number of solution pairs to an equation and $y^2 = \frac{x^5 - 1}{x-1}$ & $x,y \in \mathbb{Z}$. Found using Approach0. — Martin Sleziak 1 min ago

Professor Vector

If there's a duplicate with an answer, that changes the matter completely.

Martin Sleziak

And I missed this one: Integer squares of the form $x^4+x^3+x^2+x+1$.

One of the closed posts mentions that this is from: "BdMO 2016 Regionals Set 1 Question 3." (I suppose Bd = Bangladesh...?)

user21820

@ProfessorVector Sure. I would also take offense with a hint telling the asker to try small cases if the question was that one you just proposed...

Martin Sleziak

12:05 PM

duplicates 1835990: Integer squares of the form $x^4+x^3+x^2+x+1$ and 1270599:Determining all the positive integers $n$ such that $n^4+n^3+n^2+n+1$ is a perfect square.. Close as duplicate? In what direction?

Maybe even merging would be an option? (in such case the answer to be moved to the other post would need edit, so that the notation fits the question.)

I'd suggest to close the newer question as a duplicate of the older one and then flag for merging.

The Great Duck

5:42 PM

@user21820 yes but consider my question "Why does the shape of the multiplication operator change shape." It really doesn't need context as it isn't that sort of question. (A request for a proof or a solution to the problem). Its context is... inherent in asking the question.

hence why a "level of rigor" or "level of knowledge" name would be preferable to me as to me it seems closer to the sort of context we are looking for in an MSE question.

plus asking for "context" is a bit vague to some whereas "level of rigor/knowledge" gets straight to the point.

Xander Henderson

@TheGreatDuck The question "Why does the shape of the multiplication operator change shape." is not really a good question all by itself---it lacks context.

What do you mean "the shape of the multiplication operator"?

The Great Duck

@XanderHenderson it is specified in the question itself. That is just the title.

Xander Henderson

Is the question about why different symbols are used in different contexts, or about a terrible TeX install that doesn't consistently use a specific font?

Ah. You didn't link to the question. :)

The Great Duck

it changes from x as the symbol to $\cdot$ as the symbol

of " " as some smart-alek put it

;-)

Xander Henderson

$\times$, $\cdot$, $\ast$, $\otimes$, etc :)

The Great Duck

5:53 PM

67

Q: Why does the symbol for the multiplication operation change shape?

Why does the "$\times$" used in arithmetic change to a "$\cdot$" as we progress through education? The symbol seems to only be ambiguous because of the variable $x$; however, we wouldn't have chosen the variable $x$ unless we were already removing $\times$ as the symbol for multiplication. So why...

notation arithmetic

there

Xander Henderson

well, that question has context :)

The Great Duck

i figured with it being such a popular question (and my most ever upvoted question) that it would be easy to find

@XanderHenderson no there is not. Where do I state why I am asking the question?

Xander Henderson

Yeah, but your rep is over 100 now... I think I should downvote :P

The Great Duck

my rep would be over 4000

Xander Henderson

@TheGreatDuck Context doesn't mean a justification for asking the question

The Great Duck

5:54 PM

i spend it on bounties

@XanderHenderson it doesn't? I thought context = why you are asking

Xander Henderson

No, though that can provide context

It is possible to give context by explaining why you are asking

The Great Duck

well now I feel like an idiot

Xander Henderson

on the other hand, "hey, we use different symbols, wherefore?"

with some additional context about when and where the symbols get used

is good

The Great Duck

i actually occasionally post on questions telling people they need to state the reason why they are asking

thinking that they must actually give the homework/project/whatever it is being used in

@XanderHenderson to me that falls into the realm of being clear

but perhaps context can be categorized as a form of clarification

according to googling "context definition"

"con·text
ˈkäntekst/
noun
noun: context; plural noun: contexts

the circumstances that form the setting for an event, statement, or idea, and in terms of which it can be fully understood and assessed.
"the decision was taken within the context of planned cuts in spending"
synonyms: circumstances, conditions, factors, state of affairs, situation, background, scene, setting More
"the wider historical context"
frame of reference, contextual relationship;
text, subject, theme, topic
"a quote taken out of context"

"the circumstances that form the setting for an event, statement, or idea, and in terms of which it can be fully understood and assessed."

my emphasis

I guess i mistook that as meaning the literal events leading up to asking the question

Xander Henderson

The question is "Why do we use different symbols", which is clear all by itself; context for the question is "Hey, third graders use $\times$ while grown ups use $\cdot$ (or nothing at all)."

The Great Duck

5:59 PM

@XanderHenderson I guess I never thought of it that way.

still, some questions need context, whereas others need clarity, and others need rigor and formalism

unfortunately nothing for the last one exists and is imo much more predominant of a need than pure context

as generally context and clarity go hand in hand

i mean in the sense that just asking why they change is unclear whereas stating why does "x" change to "$\cdot$" is clearer.

Xander Henderson

All questions require clarity and context

The Great Duck

i meant that context = clarity in most cases

Xander Henderson

it is just that the context is often fairly minimal, or intrinsic to the question itself

The Great Duck

OR context = rigor

therefore replace "context" with "clarity" and "rigor" denotations

Xander Henderson

again, I think that all three are distinct ideas

The Great Duck

6:03 PM

if there is a sort of lack of context that cannot be equated to a lack of clarity or a lack of rigor then my bad.

Xander Henderson

one can ask a very clear question with zero context

or a rigorous question that isn't clear

The Great Duck

yes but is there a rigorous and clear question that lacks context that we require for questions on this site?

Xander Henderson

"How do I solve the equation $2x+1 = 5$ for $x$?" is a very clear question that is rigorously stated, but which lacks any context.

The Great Duck

oooh

i see

Xander Henderson

i.e. the typical PSQ

The Great Duck

6:05 PM

i dont actually know that acronym

i know it = bad question

Xander Henderson

Problem Statement Question

The Great Duck

oh

i see

Xander Henderson

or "Please Solve" Question

The Great Duck

to be fair though, for sufficiently advanced and novel questions, the question is sometimes enough

Xander Henderson

indeed, it can be

The Great Duck

6:06 PM

such as "verify that this construction is rigorous and valid as a mathematical construction"

Xander Henderson

but rarely is

The Great Duck

yeah it probably takes sometimes homebrew at least

Xander Henderson

But "verify" requires context, in the sense that you have to give details of the thing that you are verifying...

The Great Duck

eeeh

that's not context

the question is "verify x is rigorous"

if you dont fill in x then its not even a question

context would be the logical framework you are working in i suppose

like zfc

or first order logic

in my eyes, context is the sort of thing you can leave out by accident even if you completely and perfectly state the query you have as a query.

otherwise the question statement itself is not valid and therefore suffers from one of the other two

and since "context" is vague

Xander Henderson

context is vague---it can mean different things in different questions

The Great Duck

6:11 PM

well i meant like in a PSQ

Xander Henderson

I guess that CONTEXT matters when considering how to provide proper CONTEXT

har har

The Great Duck

as a query it is perfect

in the sense that if you asked someone to solve it, they could

i.e. the query could be placed into a textbook of appropriate knowledge level and it wouldnt be out of place

whereas something that doesnt fit that criteria

is either unclear or not rigorous (or something that wouldn't belong in a textbook such as my linked question)

but the last is mostly going to be outliers

amWhy

@TheGreatDuck Do you have a question about whether this question should be closed or reopened or undelted, or deleted, or edited? Now, currently? I mean, since this is CRUDE, I'm assuming you've posted your question in order to ask folks to CRUD or E?

amWhy

8:23 PM

@Did, @user21820, @SimplyBeautifulArt, @ZacharySelk, @others: This answer is (1) wrong, and (2) answers the answerer's presumption of what the asker must have meant, aiming to answer wrt $f(x) = \frac 1{x+1}$, when in fact, the asker wrote "f(x) = 1/x +1", and despite two requests to the asker to indicate whether she meant f(x) = (1/x) + 1 or f(x) = 1/(x+1), she has yet to answer. The question is now closed, but the "answer" remains.

amWhy

9:59 PM

PSQ awaiting a final delete vote, @Did, @user21820, @ZacharySelk, @SimplyBeautifulArt, @others.

For those with access to user-level-mod-tools, skim through the questions open for deletion with only one more delete vote; perhaps they were missed in reviewing very poor questions/answers.

The Great Duck

@amWhy no. I posted it because it was an example relevant to the discussion. Next time please read the context.

we were discussing the proposal to modify the context close vote description

i gave that as an example where context isnt explicitly relevant

amWhy

10:14 PM

Not a good example, because context is explicit. All askers are asked to make their posts relevant, and contribute their own efforts when asking a question. That holds for high level and lower level questions. Besides, what defines "higher level questions" which should be able to merely post problem statements, period? That would take another discussion. When does that become elitism, and what about conflicts between users who argue about whether a question is "higher level"?

@TheGreatDuck Anyway, thanks for clarifying your drawn out comments. No one should be obliged to read three pages of transcripts in order to figure out what the posting of an MSE question is for. Again, questions, and links to them, and answers and links to them should be reserved for that which addresses proposals about current answers and questions.

Transcript for

$Mathematics$ CURED