Conversation started May 31, 2019 at 16:03.
darij grinberg
darij grinberg
May 31, 2019 16:03
This should not be on the D-list; it's an inequality of fairly reasonable interest to the inequality community and the OP has mentioned trying the obvious -- what other context would we expect?
Same for this
and this is a really nice exercise
 
4 hours later…
Alexander Gruber
Alexander Gruber
May 31, 2019 20:28
@darijgrinberg that might make a good meta question-- e.g. what are best practices for context in the inequalities tag?
it seems to come up enough that it isn't obvious how to apply the usual standards within that tag. Lots of well-received PSQs there
darij grinberg
darij grinberg
May 31, 2019 21:20
Frankly, I think the general consensus is a lot less radical than you are on PSQs when they are of interest to more people than the OP.
But yes, on inequalities and triangle geometry it seems to differ the most.
My impression is, a lot of people come here from AoPS, where context is unusual (sometimes mods delete contexts in order to keep the OP "pure" for possible inclusion in contest lists).
It's a sudden and badly-documented change in expectations.
But even apart from that, math olympiad people find it annoying to protocol their failed attempts -- most of the time, there is no such thing as "a bit of progress".
I think a post with context is better than one without, unless the context is complete crap (my personal threshold for deleting context is when it is actively confusing, such as wrong definitions or nonsense) -- but that's not something commonly understood, methinks.
quid
quid
May 31, 2019 22:21
@darijgrinberg usually those problems come from somewhere though. At least the source should be specified and it should be placed explicitly in the context of competition mathematics.
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Are you familiar with the method of Lagrange multipliers? — K.Power May 8 '17 at 18:23
^^ shows why context would be important.
Depending on context one or the other answer is presumably the desired one.
Now, some might say who cares lets give both or all, but that's not always desirable, as far as I am concerned.
Anyway, what seem clear is that context could change something for the question, contrary to claims that it's not useful.
Tangentially, the Lagrange multiplier answer also seems to show that the question is not really interesting at all except maybe as to show the value of learning some actual mathematics rather than spending ones time fiddling around with the same handful of tricks.
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It's a shame that at high-school level often that type of pseudo-mathematics is the only thing that is offered to interested students.
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quid
quid
May 31, 2019 22:47
@darijgrinberg to be clear regarding this at the risk of repetition: the source of the question, as incidentally requested in a comment years ago (by somebody that seems not generally hostile to this type of content).
@darijgrinberg same for this. :-)
@darijgrinberg this does include a bit of what I'd consider relevant context. Excluding derivatives as tools and indicating their background (10th grade).
darij grinberg
darij grinberg
May 31, 2019 23:22
"Use Lagrange multipliers" is a meaningless cheap comment. 50% of inequalities can be done with them (if you have a computer). It's like saying "have you tried induction?" or "use Cartesian coordinates". I often flag such comments for deletion if they don't come with any more pertinent content.
quid
quid
@darijgrinberg what's your point? The question is whether the method is admissible or not. In the current case the application seems straightforward. But that's irrelevant to the point. The problem is that due to lack of context it is not clear if the method is admissible in the given context. It might be. Or it might not be. Could be a contest problem, could also be calculus homework.
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On the rest, well, so why do those problems?
Same for all those 'hard' integrals.
Seems just like a waste of time, in any case pseudo-mathematics.
quid
quid
Jun 1, 2019 00:14
But not to get side-tracked once again:
The missing context is the source of the problem and whether methods like Lagrange modifiers are acceptable or not.
(The latter would usually be given implicitly by mentioning general background, as OP of course cannot be expected to know about what they don't know.)
I don't think that this is asking for all that much. Nothing about failed attempts etc.
 
Conversation ended Jun 1, 2019 at 0:17.