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I'll just put this out here. This is a sock my main account is Avnish Kabaj and user619072(now deleted sock).

I've asked a couple of questions as to why my method is wrong. For some reason, users keep on providing an alternative solution.That always defeats the purpose of the question. I never get to learn what's wrong with my thinking and whatever bungled up math concepts I'm using remain bungled up.

Why does this happen? Am I framing my questions incorrectly? Do users not like questions where I want my method to be corrected? A couple of hours ago I asked a question and wrote clearly at the top that I'm not after the answer.

I got two answers none of which provided as to why was my method incorrect. It's not that I don't appreciate the answers I've learnt lots of cool ways at looking at math and neat tricks which I could have never discovered on my own.

It's just that I asked for an orange but got an apple instead, apples are tasty but aren't oranges.

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    $\begingroup$ Yeah, isn't that annoying? I also dislike when that happens. All you can really do is leave a polite comment that says "thanks, but what I really wanted was to understand my own mistake". $\endgroup$ – MJD Apr 13 at 16:21
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    $\begingroup$ Isn't there a way to report/flag this kind of things for "not an answer to the question"? $\endgroup$ – Number Apr 13 at 18:53
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    $\begingroup$ I think that it might be useful to mark the questions of the type you describe with the (solution-verification) tag. Some related previous discussions: Answering “is my approach correct” with a different proof and Is it acceptable to provide alternative solutions to proof verification questions after the “proof verification” has been answered? $\endgroup$ – Martin Sleziak Apr 13 at 23:49
  • $\begingroup$ @MartinSleziak Thanks, I never knew such a tag existed i shall use it now onwards in relevant questions. $\endgroup$ – user659291 Apr 14 at 2:50
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    $\begingroup$ "Why do users give answers using alternative method when I'm asking what went wrong with my solution?" Because they can. Maybe they can't figure out what went wrong with your solution, so they do what they reckon is the next best thing, and provide a method that works. You're no worse off for someone doing that, so what is your problem? $\endgroup$ – Gerry Myerson Apr 14 at 4:14
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    $\begingroup$ I think the best you can do (since in this site people contribute for free) is to say $\color{blue}{thank\ you}$ for whatever but I am looking for whatever and perhaps not to accept the answer given and wait until somebody else gives what you ask for. $\endgroup$ – Isa Apr 14 at 6:45
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    $\begingroup$ @GerryMyerson - I disagree emphatically that the asker is "no worse off" when someone gives a solution from scratch using a totally different approach. They lose the experience of finding the correct approach without knowing it in advance. (Suppose you ask me the showtime of a movie -- are you "no worse off" if, not knowing when the movie is showing, I decide to just tell you the ending instead?) $\endgroup$ – Gregory J. Puleo Apr 14 at 16:23
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    $\begingroup$ There are two very different sorts of situations, in which an answer might not floow your desired path. One is if you ask something like "can you prove $P$ without using the axiom of choice; here is my attempt" and the answerer proves $P$ using AC. That answer is plain wrong!. The other is where your "proof" is so obfuscated that it is too hard to follow and identify the bad step; the answerer is trying to do you a favor by presenting a more well-organized approach. If your answer really is unnecessarily contorted, that is fair. $\endgroup$ – Mark Fischler Apr 15 at 22:54
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    $\begingroup$ Just a remark: Reading your question, the part at the top "I am not after the answer" is a bit cryptic to me. Then comes the text, if I read it quickly the impression I get is that you are asking "how can this be done?". In part because the crucial sentence fragment "why is this an incorrect method to go about solving the question." is not separated from the text clearly. I think you will get answers more in line with what you want if you pay special attention in marking what exactly is the question. Use the orange ">" quote block for example to highlight your exact question. $\endgroup$ – s.harp Apr 20 at 7:16
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    $\begingroup$ It's often easier to give a better solution than to try to understand an incorrect solution and to find the error in it. And, we all like to show our knowledge, don't we? $\endgroup$ – md2perpe Apr 20 at 15:46
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    $\begingroup$ @GerryMyerson: It is a distinct possibility that other prospective answerers will be less likely to answer this question because they see it already has one, even if it doesn't actually address the OP's concerns. $\endgroup$ – Brian Tung Apr 21 at 19:38
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    $\begingroup$ Keep in mind, that there are many people visiting this site and your question. So sometimes someone wants to give an answer appeling to the wider crowd, or just want to show, that math is beautiful. That is what I did here, 'ignoring' the specific question: math.stackexchange.com/questions/2589176/… But I think it adds something to it, to have an alternativ approach. So everybody (or more) people can learn from that question. So why not answer with an alternativ? $\endgroup$ – Cornman Apr 21 at 23:35
  • $\begingroup$ @Zacky I think "not an answer" applies when the answer can't possibly be an answer to any question (eg, "I have this question to"). If it's a possibly valid answer, then it should be voted on, not flagged. $\endgroup$ – Teepeemm Apr 23 at 23:05
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    $\begingroup$ I left a comment to this effect on the question, but I think your main problem is that you are asking "what's wrong with my approach", but you've only shown us "Using $f(0)=2$ we get $f(5)=2$." There needs to be much more detail if we're going to spot what went wrong. $\endgroup$ – Teepeemm Apr 23 at 23:15
  • $\begingroup$ You gain more experience when you see how people(probably smarter than us) solve the similar tasks, I agree it's not what you were looking for exactly but at the end it will help you only to understand that perspective as well, (and we can always profile the code to see what's causing it delay) $\endgroup$ – Aditya Apr 24 at 8:51
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Many aspects to this. I agree to a great extent with the points raised in the other answers. Yes, there are XY problems. Yes, the question is not here just for the benefit of the asker, and this shows in our expectations and also in the answers.

I want to emphasize one aspect not present in the other answers.

The actual mathematical problem underlying such questions has often been already asked and answered earlier in our site. In such a case a new question asking about weaknesses/strengths of alternative attacks to a problem requires, in my opinion, a different treatment.

A not atypical scenario is that the asker actually did their homework and searched the site, found a closely related question with one or more answers. And their question then is about the validity/pitfalls in their alternative line of attack. What happens uncomfortably often is that the answerers ignore the background work, and simply repost (correct) answers to the mathematical question. When prompted, they regurgitate the (good) reasons in the other answers. This gives me pimples. I want to discourage that practice.

  • In such a case the only thing stopping the current question from being a duplicate is the fact that its focus is on the viability of another approach.
  • Therefore a correct solution to the underlying question that does not discuss the OP's alternative approach is not an answer. Effectively, the act of posting a "mainstream" answer then proves that the question was, indeed, a duplicate, and should be closed as such.
  • In other words, the answerers don't have a leg to stand on. Either they did not discuss the actual question at all, or, if citing XY and friends, they answered a duplicate question.
  • Observe that, as usual, the answerers have the option to post their chosen approach as an answer to the "duplicate" target.

To a significant extent this problem is present in all solution-verification and proof-verification questions. It recurs often enough for it to be prudent to discuss and formulate a policy. However, that should be discussed elsewhere. For example here, or in one of the other threads linked to that one.

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Not the exact answer to your situation, but it might give some idea, so in that sense, this answer is also an alternative answer to the question that you are asking.

We are not your tutor in here, nor this is a website you are getting personalised service; even though you are owner of your own question, the main purpose of that question is to both help you, and help the future readers. For that reason, even though you are not interested in an alternative answer, someone else might!

Plus, mathematically speaking, even though a given answer is a valid answer as long as it is correct, it might not be an intuitive one, nor could be something that can be understood easily. In that sense, knowing alternative answers, solution methods, proof etc. is often very (very) useful, and that is one of the reasons why people answers to questions, which has an accepted answer, with alternative answers.

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    $\begingroup$ It is a good idea to state clearly in the first sentence of an alternative answer that it an alternative (so that readers who are not interested in such don't need to (hopefully) infer that by reading the entire answer). $\endgroup$ – Bill Dubuque Apr 13 at 18:30
  • $\begingroup$ @BillDubuque I hope it is OK now ? $\endgroup$ – onurcanbektas Apr 13 at 18:32
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    $\begingroup$ I was referring to the first sentence of the alternative answer - not yours. I edited to clarify. $\endgroup$ – Bill Dubuque Apr 13 at 18:34
  • $\begingroup$ @BillDubuque Oh I see; I agree on that. $\endgroup$ – onurcanbektas Apr 13 at 18:36
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    $\begingroup$ I think it's a balancing act though. Usually it is not alright to completely ignore the specific question and to just write something related to the problem the question is about. If somebody has a question on a specific approach to some problem they have a right to have their question respected. It is not really an alternative answer to the question asked (maybe to the underlying problem, but that's not the same). It also runs the risk of effectively turning the question into a duplicate. $\endgroup$ – quid Apr 13 at 20:15
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    $\begingroup$ I think it is always better to point out the mistake of the asker apart from giving an alternative approach. If one answer has already pointed out the mistake then I don't repeat the same in my answer but rather link to it and provide an alternative approach. $\endgroup$ – Paramanand Singh Apr 14 at 1:58
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    $\begingroup$ Unfortunately, giving a completely different approach makes math seem like magic for students who don't have the mathematical maturity. $\endgroup$ – user1952500 Apr 21 at 14:47
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    $\begingroup$ @user1952500 By seeing different approaches, you discover the different parts of the math that you don't know about, which means that you can study them and become mature.Otherwise, how can you start studying something that you don't even aware that such a thing exists. $\endgroup$ – onurcanbektas Apr 21 at 14:50
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    $\begingroup$ @onurcanbektas I agree to an extent, but that is not the way the user will do math always. They need to know that they can plod through their bad approach and still reach the solution, and then they need to know that a better solution exists. Think about solving IMO problems and looking at the elegant solution after coming up with a laborious one. If we all look at solutions from 'the book', it won't help us learn many other things. $\endgroup$ – user1952500 Apr 21 at 14:52
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    $\begingroup$ @user1952500 Of course, I totally agree on that, but as a side answer (not the answer that should accepted), those "alternative" answer are quite helpful. $\endgroup$ – onurcanbektas Apr 21 at 14:57
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    $\begingroup$ @onurcanbektas hmm, that's possibly true. As a bystander I agree but I'm not sure what the OP will think of this. For me, knowing what went wrong is very useful especially in areas like Combinatorics where there are literally dozens of ways to enumerate. If I ask a question there, I would very likely accept something which detailed what went wrong and how I can go about it. But that's on a case-by-case basis. $\endgroup$ – user1952500 Apr 21 at 15:00
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    $\begingroup$ @quid Sometimes, mainly when I started here, I've a problem of not reading the question properly vs. it being not respecting the OP's request. In one case, I answered the wrong question but it was accepted, so I had to ask the OP to unaccept it so I could delete it. Recently, the OP's last line here was "Where's my mistake?How to get the right answer?". $3$ commenters & $2$ high rep. answerers with other solutions, all ignored the mistake, so it happens to experienced answerers, but I explained the mistake. $\endgroup$ – John Omielan May 12 at 0:51
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There are quite a lot of XY problems so that people may sometimes have difficulties understanding what OP is really asking and directly answer the mathematical problem highlighted in the post. There were cases that one asked what went wrong in one's attempt while what one really cared was the solution itself.

On the other hand, if one wants to avoid getting an apple, perhaps one could make one's request for the desired orange more explicitly. If I were you, I would write the question differently as follows. (Since your question is under discussion, I would not touch it in the main site.)


[Title:] Where did I do wrong in finding $f(5)$ where $2+ f(x)f(y)=f(x)+f(y) +f(xy)$ and $f(2)=5$?


[Body of the post:]

Consider the following problem:

Suppose $2+ f(x)f(y)=f(x)+f(y) +f(xy)$. If $f(2)=5$, find $f(5)$.

A similar problem has been asked before. The solution is $f(5)=26$. I would like to understand what is going wrong in my following attempt.

Plugging in $0$ gives us a quadratic equation in $f(0)$, which implies that $f(0)=1$ or $f(0)=2$.

Now, if I take $x=5$ and $y=0$, using $f(0)=1$ gives us $1=1$, which is not useful.

Using $f(0)=2$ we get $f(5)=2$, which is not the desired solution.

Question:

Where did I do wrong in the attempt above?


Just my two cents.

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    $\begingroup$ This is very worthwhile advice and I think the most worthwhile part of it is changing the title. If you're not interested in alternative answers to problem X, you should not put "how to solve X" in the title, but "what is wrong with this solution to X". If your question is called "how to solve X", you will naturally attract people who have a solution to X they want to share. (Maybe those people will then carefully read what you're asking, and maybe they won't.) $\endgroup$ – Misha Lavrov Apr 14 at 15:48
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    $\begingroup$ While I don't think it's a big issue for the OP's referenced question, in general, something that would help avoid ambiguity and get more useful answers all around is to state why you're doing each step and/or the plan you're using to solve the problem in more substantial cases. $\endgroup$ – Derek Elkins Apr 15 at 1:24
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I think you made your question clear enough in the initial posting, and I think everyone contributing to the discussion here would have endeavoured to answer the question you asked, not solved the problem you were working on (as well they should).

As I said, I don't think this is the case for this particular question, but sometimes answering questions like this isn't really feasible. Sometimes the logic in working is extremely muddled, making several interlocking assumptions, none of which are made explicit. In such cases, I would advise people to follow these steps:

  1. Engage the asker with comments. Find an undefined term/symbol, a short phrase that is unclear, and request clarification.
  2. If the asker does not respond with clarification (and you haven't moved on), then vote to close the question (for being unclear, or lacking context, your choice).
  3. If the asker does respond, keep commenting until the question becomes clear, then answer it if you choose.
  4. If the comments are not illuminating, then either vote to close the question if the question is unclear, or search for a duplicate answer for the given problem, and post it in a comment.
  5. If you cannot find a duplicate or the provided duplicate does not satisfy the asker, then respond with a partial solution, taking the time to explicitly refer to parts of the solution that you can match up with the asker's question (if any).

That is, responding with a full solution to such questions should only be the last resort!

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    $\begingroup$ It's also worth pointing out that some people who ask if their solutions are correct, don't really want people dissecting their working. Plenty of people just want ready-made solutions, and will happily reward answerers who post full solutions. The more savvy such people will disguise their PSQ by putting some token effort, and asking if their approach is correct, but are really hoping for a full solution. Of course, there are others who want to know their error, and figure it out for themselves from a full solution. $\endgroup$ – Theo Bendit Apr 24 at 4:01
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(I am capturing some notes from a chat into a basic answer so that it doesn't get lost).

I personally try to answer what went wrong either as a comment or as a part of my answer. I also upvote the same way. The reasoning is this: a lot of younger students who don't have enough mathematical maturity think of Maths as a bag of tricks with the right trick to be discovered and applied for a problem. While this could be true in a generic sense, I want to ensure that the students know why their approach is wrong, and how another approach could be easier.

This will not help other readers who read the site to increase their knowledge (including me). However it helps in improving Mathematical knowledge in the world.

Consider the case where someone is trying to enumerate in a combinatorial problem and reaches an error. If someone answers with an entirely new way to enumerate, will it help the OP? Should the OP think that the method used by them is incorrect and should never be used, or should they use it with caution?

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Think of it that way - if somebody were to know the answer to your question, they would give it. If they don't say it - well, they just don't know it.

I also find it extremely annoying because analysing the solution and why it worked out is important and beneficial to get a sense what is going on and why it goes that way. But giving an alternative solution is always easier.

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  • $\begingroup$ I think this is the key point. When I read a math paper, if I don't understand someone else's proof, the first question is whether I can just prove the result myself with my own methods. If I can, their proof doesn't matter as much. Of course there are new methods to learn, but the first goal is just to have a proof of the result. $\endgroup$ – Carl Mummert Apr 24 at 12:46

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