# What was wrong with my post?

Forgive me, I do not know where else to post this - I assume this is the right place.

Prove that g has no roots

It recevied a negative voting score and since I am new and wanting to learn the rules and not upset anybody I wish to ask what it is precisely that I did incorrectly on my post above. Had I tagged it incorrectly? Is it an improper question?

## migrated from math.stackexchange.comAug 28 '17 at 20:16

This question came from our site for people studying math at any level and professionals in related fields.

• Your original post looks fine to me (I upvoted it), although it's best not to link to other pages. (Some users might downvote upon seeing the link without even reading the rest of your post.) The current post should be a discussion in Meta, though. – Théophile Aug 28 '17 at 20:02
• Questions about this site, both technical and about the community and what is OK or not, belongs on meta.math.SE. I have voted to have this question moved there. – Arthur Aug 28 '17 at 20:02
• @Peter But the OP did explain where he got stuck and why. – Théophile Aug 28 '17 at 20:04
• I did try to add this post to meta but wasn't sure how to. A tag did not come up. @Arthur How do I move it/or post on math.meta.SE in future? – Benjamin Aug 28 '17 at 20:05
• Then, I do not understand the bad reactions. Unfortunately, many questions are downvoted/closedvoted without apparant reasons. – Peter Aug 28 '17 at 20:06
• But the linked question received $3$ upvotes, one downvote and no close-vote. Not too bad. A single downvote is not at all significant for the quality of a question. – Peter Aug 28 '17 at 20:10
• At the time it was the only vote – Benjamin Aug 28 '17 at 20:14
• And, to supplement @Wills comment, there are far more people who will upvote anything, (who also answer anything they can (or can't)). – amWhy Aug 28 '17 at 20:30
• @amWhy I totally agree. Many questions and answers are massively upvoted without apparent reasons. And often questions which are already answered completely with some comments nevertheless receive several answers adding nothing to the comments. And those answers often are upvoted as well. – Peter Aug 29 '17 at 23:49
• Well, as a reaction to this post, many users rushed in to your post and upvoted it. This shouldn't have happened ideally, your question, while it's not the worst, it's nothing special and contains quite little effort put into it. This is not your fault, but I would hope we as a community understand that the way to fix 2 or 3 downvotes is not to cast 20 upvotes. – Santropedro Sep 10 '17 at 17:27

You shouldn't take single downvotes too serious. If you receive many more downvotes than upvotes, something is probably wrong with your question, but I had many questions starting with $1$ or several downvotes which were upvoted some time later.

Single downvotes need not be justified, but you will have to live with them on this site. Sometimes, even the topic (for example prime numbers) can attract downvotes even if the question is very interesting.

• The topic "prime numbers" is "attracting downvotes"? Is this a recognized fact, substantiated by some solid evidence? – Did Aug 29 '17 at 9:51
• @Did I think they mean certain pop sci topics tend to be received harshly, even if it is a good question. Like if someone asks an appropriate question about "the Riemann Hypothesis" people automatically assume they're a crank and downvote away, even if it is a good/appropriate question. – user223391 Aug 29 '17 at 16:13
• @ZacharySelk Tons of unproven assumptions here (and in your own comment), I am afraid. One would love to see data proving that questions about the RH receive a significantly greater proportion of unmotivated downvotes. – Did Aug 29 '17 at 16:17
• @Did Of course I don't have data to back this up and I doubt Peter does either. But it's just something I've seen. I would like to see some evidence as well. – user223391 Aug 29 '17 at 16:18
• I am shocked that such a harmless answer results in such reactions. My claim is only that SOMETIMES even the topic CAN attract downvotes, and Zachary admits that this claim is not totally absurd. I have not posted many answers in meta, and if this is the result, I won't do it in the future. If the question will be deleted, I will have to accept this, but I do not see a reason to delete it myself. – Peter Aug 29 '17 at 21:31
• @Peter, indeed there are much more important issues to deal with than as in your post. I actually *upvoted the post". In any case, I will delete most, if not all, of my comments, so as not to distract from the question at hand. Done, save for this comment. – amWhy Aug 29 '17 at 22:51
• @Peter In case your "shocked" comment is actually addressed at me, let me note that: 1. you should ping me, not some other user, 2. in my world, there is nothing shocking in asking for solid evidence substantiating a claim, 3. at present, I am forced to put the statement " the topic (for example prime numbers) can attract downvotes even if the question is very interesting" in the collection of unsubstantiated opinions (but I would be delighted to put it out if data, or arguments, come). – Did Aug 29 '17 at 22:58
• @Did To backup my claim with statistics, I would have to list several links to questions about primes which received downvotes. I do not think that this is actually useful. Since I deleted several of the questions because they obviously weren't welcome, I am probably not able to convince sceptisists to believe my claim. Often, when I asked for a prime of some form , several downvotes were the result, and comments like "why do you want such a prime? " appeared quite often. – Peter Aug 29 '17 at 23:21
• To clarify : I neither claim that those downvotes were wrong, nor do I claim that those downvotes always represented the opinion of the majority. – Peter Aug 29 '17 at 23:24
• @Peter: that's the fallacy of over-generalization. One user's experience does not make it's generalization ("I blamed downvotes I received on the fact that questions about primes are targeted") so therefore you were likely a victim of a (presumed) bias against prime numbers." – amWhy Aug 29 '17 at 23:26
• What is generalising in the claim that SOMETIMES a topic CAN attract downvotes ? Generalizing would be : "Some topics always receive downvotes". But I did not claim something like that. – Peter Aug 29 '17 at 23:29
• @Did OK, replace the post with "I do not claim that ALL downvotes were wrong" ... – Peter Aug 29 '17 at 23:36
• @Did I think you know what I mean. And the discussion about the exact formulation is rather off-topic. – Peter Aug 29 '17 at 23:43
• Is someone selling some popcorns? :-P – Jaideep Khare Aug 30 '17 at 11:18
• A better example of this topic problem is the good old divergent series $1+2+3+\dots=-\frac1{12}$, and all the related "I didn't get -1/12, what's wrong?" – Simply Beautiful Art Sep 7 '17 at 23:56

It is probably because the problem you quoted:

Suppose that $f:{\bf R}\to{\bf R}$ and define a function $g:{\bf R}\to{\bf R}$ by $g(x)=1/f(x)$. Prove that $g$ has no roots.

is poorly written. When $0$ is in the range of $f$, it does not make sense to say that "define a function $g:{\bf R}\to{\bf R}$ by $g(x)=1/f(x)$" and thus there is nothing to prove.

• How do we know $0$ is in the range of $f$? $\mathbb{R}$ is just the codomain isn't it? – Ovi Sep 10 '17 at 18:23
• It's not that we know that $0$ is in $f$, but rather, we don't know that $0$ isn't in the range of $f$. The problem is only well defined, as Jack pointed out, when $0$ is not in the range of $f$. – mdave16 Sep 10 '17 at 19:11