Recently I stumbled on the following questions:

1. Proof that a trigonometric function of a rational angle must be non-transcendental

2. Is a trigonometric function applied to a rational multiple of $π$ always algebraic?

They are 100% duplicates but surprisingly they weren't marked as a duplicate of each other. I find it especially strange that the first one got a huge amount of views, yet no one mentioned that it was a duplicate of the other (older) question.

Should it be left like that or should something be done?

  • 6
    $\begingroup$ I like the idea of marking the one with the least excellent best answer as duplicate of the other (regardless of the order of posting). If they're close enough, merging may be a possibility, but that can have problems (like causing unintended duplicate answers in the same thread). $\endgroup$ Feb 8, 2017 at 20:41
  • $\begingroup$ At least they should be linked, and now they are because I posted the URL of the older one in a comment on the newer one. $\endgroup$ Feb 8, 2017 at 20:52
  • 1
    $\begingroup$ Why does almost every single MetaMSE question I look at have exactly one downvote? And why does this have any downvotes at all? $\endgroup$
    – user307169
    Feb 16, 2017 at 19:05

2 Answers 2


There are so many questions; plenty of things just fall through the cracks.

When you come across clear-cut old duplicates flag/vote one of them as such. (Click "flag" select "a duplicate" etc.)

Which one you flag is in a way up to you. Generally, one will want to give most visibility to the subjectively best thread, so flag the other one.

  • $\begingroup$ Better not to use flags, since that minimizes the number of community members involved in the duplicity decision. $\endgroup$ Feb 20, 2017 at 23:34
  • $\begingroup$ Are you also against casting a (simple) vote to close as duplicate? $\endgroup$
    – quid Mod
    Feb 21, 2017 at 0:11
  • $\begingroup$ Are you against staying on topic? $\endgroup$ Feb 21, 2017 at 0:13
  • 2
    $\begingroup$ I ask for clarification regarding the scope of your concern. It is beyond me why you would not provide this information, and even more how such a request could be off-topic. $\endgroup$
    – quid Mod
    Feb 21, 2017 at 0:54
  • 3
    $\begingroup$ @BillDubuque My understanding is that when a user with less than 3k flags as a duplicate, the post enters close review queue. The same happens for a duplicate close vote. (The difference is that it already has one close vote.) For 3k+ users there is actually no difference between the duplicate close vote and corresponding flag. See meta.math.stackexchange.com/q/23592 and meta.math.stackexchange.com/q/21547 So unless I am missing something, there is no substantial difference between the two possibilities. $\endgroup$ Feb 21, 2017 at 5:26
  • $\begingroup$ @Martin It is not too infrequent that certain users flag to get moderators to to attempt to unilaterally reverse decisions that they disagree with (e.g. reversing reopens). That is one of the cases that I had in mind. $\endgroup$ Feb 21, 2017 at 13:57
  • $\begingroup$ @BillDubuque what flag do they use to this end? "a duplicate" I don't think so. Hence it is completely unrelated to my suggested course of action. Can you stay on-topic? $\endgroup$
    – quid Mod
    Feb 21, 2017 at 18:08
  • $\begingroup$ @quid I don't know (the mod simply said it was flagged as a duplicate in the cases I asked about). But my point should be clear: try to choose a method that will result in the most fair (and accurate) community decision on the matter. Even better, try to ensure it gets exposure to users that have the most experience and knowledge on such matters, so that the most informed decisions can be made (vs. robo-votes). $\endgroup$ Feb 21, 2017 at 18:17
  • $\begingroup$ @BillDubuque no your point is not clear at all since you refuse to state if you consider a vote to close as duplicate as an appropriate method or not. $\endgroup$
    – quid Mod
    Feb 21, 2017 at 18:20
  • $\begingroup$ @quid That has nothing to do with the points I mention. $\endgroup$ Feb 21, 2017 at 18:21

I would venture to say that "do nothing" might be a good option, especially in this case where both questions have reasonable answers. Putting a link to the other question in a comment for each would be a friendly way to make access to both questions' answers easier.


Not the answer you're looking for? Browse other questions tagged .