Just one more thing This is getting old, sometimes I answer a Q and it feels like doing tech support for my uncle or neighbor. You know, they call every few days with "one more thing".  Case:   Here, they accept an answer and thank you for the help, then come back the next day, take back the 15 rep, and change the question scope in the comments.  How can I reply to comments like this better in the future? Any suggestions on kindly asking the OP to just make a new question rather than appointing me as their personal help desk?
Exit strategies for "chameleon questions" I'm not sure if there's already an existing term for this, so I'm inventing my own. (tl;dr: I call them &quot;chameleon questions&quot; because they change every time you submit or edit an answer.  If you're already intimately familiar with the phenomenon, please skip past the first set of bullet points to where I ask for recommendations.)  I think many of us have experienced this on occasion:  You open up a narrow-looking question, usually dealing with some specific error message.  The question probably contains a snippet of sloppy but not quite awful code; code indicating that the author, typically a new/low-rep user, possibly a , doesn't really know what they're doing.  I'm not trying to be condescending here, they're probably very intelligent and hardworking, but in this specific case, they're clearly in way over their head.  However, as a question, it's not really too bad.  The goal and problem are both clearly stated.  The code is formatted (sort of).  Mort was polite and checked their spelling.  The question looks answerable, although from a rep perspective* it's an obvious dead-end, it's had maybe 3 views in the past 30 minutes.  So you decide, you know what, this person took the time to write up the question properly, they deserve an answer, put on your good citizen hat and throw them a bone.  You slog through the ugly code, find the offending line, direct their attention to it and explain why it's wrong and how it needs to be fixed.  Later, they leave a comment saying that yes, that was indeed the problem and your answer helped them fix it (great!).  Oh, but, now there's another problem (uh-oh...). Something else is broken.  After letting out a long sigh, you read the comment and/or edited question, roll up your sleeves, and write up Take 2, hoping that's the end of it.  And of course it's not the end.  Now maybe the error is gone, but it's not doing what it's supposed to.  If you're anything like me, your patience is now starting to wear thin. It's lousy code and you didn't volunteer to help them rewrite their whole app.  And of course, the question still only has 12 views, and nobody has upvoted either the question or your answer, including the person you're helping, so this is turning out to be a genuinely thankless task in all respects.  Welcome to &quot;Family Tech Support&quot;, Web 2.0 Edition.   * Which is of course just an arbitrary number that none of us care about. Not really, anyway. Not very much, at least.  So, here's where I get to my question.  At this point, do you:  Leave a comment, stating as politely as possible that you've done your best to help them answer the original question they asked, and if they have a new problem then they should start a new question?  (I did this once, and actually ended up with an accept, but I felt kind of guilty afterwards, I don't think anybody answered their 2nd question).  Bite the bullet and edit your answer a 3rd, 4th, 5th time, however many times it takes to resolve their issue, knowing full well that they may not even remember to accept the answer once you're done? (I may work for free on SO, but that doesn't mean my time is worthless.)  Just abandon the question, hoping that it will force Mort to start thinking for himself?  Something else?   I've tried all three of the above and none of them ever quite feel right. I do want to help, but at the same time there are a lot more &quot;lucrative&quot; questions I could be answering. And I don't mind spending a lot of time on an answer either, if the question is interesting or important to me, but debugging is dull work. I'd prefer not to reference specific questions here; I'm pretty sure that this is a shared experience, and my objective isn't to point fingers at &quot;misbehaving&quot; members.  I'm more looking for some practical advice on how to dig myself out of these pits of despair. Anybody have any other ideas?
When is $\mathbb{F}_p[x]/(x^2-2)\simeq\mathbb{F}_p[x]/(x^2-3)$ for small primes? I've been considering the rings $R_1=\mathbb{F}_p[x]/(x^2-2)$ and $R_2=\mathbb{F}_p[x]/(x^2-3)$, where $\mathbb{F}_p=\mathbb{Z}/(p)$.   I'm trying to figure out if they're isomorphic (as rings I suppose) or not for primes $p=2,5,11$.   I don't think they are for $p=11$, since $x^2-2$ is irreducible over $\mathbb{F}_{11}$, so $R_1$ is a field. But $x^2-3$ has $x=5,6$ as solution in $\mathbb{F}_{11}$, so $R_2$ is not even a domain.  For $p=5$, both polynomials are irreducible, so both rings are fields with $25$ elements.  I know from my previous studies that any two finite fields of the same order are isomorphic, but I'm curious if there is a simpler way to show the isomorphism in this case, without resorting to that theorem.  For $p=2$, neither ring is even a domain as $x=0$ is a solution of $x^2-2$ and $x=1$ is a solution for $x^2-3$, but I'm not sure how to proceed after that. Thank you for any help. What causes this corkscrew-shaped object to rise up in a stream of water falling down? Why does the "Unanswered Questions" tab show questions that have answers? What is the secondary CPU Usage Graph line in the Windows 10 Task Manager I was looking at the task manager in Windows 10 and for the first time noticed a secondary dashed line below the solid? What does this line indicate? Why are my textures pink? Why is channel capacity a factor of bandwidth instead of frequency? I'm trying to understand the concept of capacity for a wireless channel.  Some help would be appreciated.  For a AWGN channel capacity is calculated as:  $$C=B \cdot log_2(1 + S/N)\text{ bits/sec}$$  B = bandwidth.  This is what I don't understand.  Why isn't it a factor of frequency? To me considering bandwidth only makes sense in cases where the system changes frequency.   Bandwidth is the difference between an upper and lower frequency range.  Well, what if I'm using a fixed-frequency signal?  Fupper and Flower would be the same value, right?  So does that mean B=0?  So a fixed frequency signal can't carry any data?  We know that's not true, AM radio does it.  So what am I missing? According to this formula, a fixed-frequency signal would have the same performance regardless of whether it's at high or low frequency.  This makes no sense to me.  For example say my bandwidth is 1Hz at a fixed frequency of 1Hz.  Compare this with a bandwidth of 1Hz at a frequency of 2.4GHz.  It's plainly obvious that I can cram way more bits into 2.4 x 109 cycles/second than I can with just 1/sec.  But according to this formula I can't.  Please help. What about fractional differences?  Waveforms are analog in nature, so we could have a 1Hz signal and a 1.5Hz signal.  Likewise at the high frequency range.  Say 2.4GHz minus 0.5Hz.  There is an infinite amount of space between 1 and 1.5.  Could not 1Hz and 1.001Hz serve as two separate channels?  In terms of practicality I realize this would be difficult, nearly impossible to measure this difference with modern electronics, especially with noise added, but in pure theory you could have two channels.  So in that sense, shouldn't there be an infinite amount of bandwidth between two frequencies?  Or do we only count in 1Hz whole number increments? Proof of inequality $2(\sqrt{n+1}-\sqrt{n}) < \frac{1}{\sqrt{n}} < 2(\sqrt{n} - \sqrt{n-1})$ using induction Prove that $2(\sqrt{n+1}-\sqrt{n}) &lt; \frac{1}{\sqrt{n}} &lt; 2(\sqrt{n} - \sqrt{n-1})$ if $n \ge 1$ using induction.  Can someone help me with this problem please. Base case is easily shown, and for the inductive step I know I have to use the inequality for $n\gt1$ to show that it is true for $n+1$, but I am not quite sure how to.   Thanks. Basic question, how do I resume interrupted / failed downloads in Firefox? Is the wave function of a particle re-created after a measurement stops? Date Difference in php on days? I am trying to understand an example from my textbook.  Let's say $Z = X + Y$, where $X$ and $Y$ are independent uniform random variables with range $[0,1]$. Then the PDF is $$f(z) = \begin{cases} z &amp; \text{for $0 &lt; z &lt; 1$} \\ 2-z &amp; \text{for $1 \le z &lt; 2$} \\ 0 &amp; \text{otherwise.} \end{cases}$$  How was this PDF obtained?   Thanks If I seem tired, can I say: "I haven't slept last night"? If not, why have I been told that we use present perfect for actions that have present effects? Accidentally moved directories under root How to determine whether a unique factorization domain is a principal ideal domain? Could someone please provide an example of a unique factorization domain that is not a principal ideal domain?  Furthermore, is there some way to determine whether a UFD is a PID? Calculating the total number of surjective functions Ampscript date range lookup I want to use LookupOrderedRows and return rows between a start and end date (last month range). What is the best way to handle using Ampscript?   I can add one date to the where using   "DateField", @varStartDate,   But if I add the below to add additional where filters  "DateField", @varStartDate,"DateField", @varEndDate,   I get this error:     "Duplicate Key Field Name: DateField"   EDIT: Also I tried the range as the var for the LookupOrderedRows using   set @strRange = StringToDate(Format(DateDiff(@strStartDate, @strEndDate, "M"),"MM/dd/yyyy"))  and then in the LookupOrderedRows just using  "DateField", @strRange  But that got an error as well. Call to a member function prepare() on a non-object PHP Help I have installed Ubuntu 12.04-64 bit on my Lenovo IdeaPad laptop, and the wired Ethernet (LAN) connection doesn't work.  Running the lspci -vv | grep Atheros command from the terminal shows me I have the AR8161 Gigabit Ethernet controller:  02:00.0 Ethernet controller: Atheros Communications Inc. AR8161 Gigabit Ethernet (rev 08)   This looks like a new product whose drivers are not built into Ubuntu.  How do I install drivers to get the AR8161 working? Array Modifier - Fit Curve too short I want to create a simple road. To do this I first want to apply an 'Array Modifier' which fits the curve. So in the Array modifier I changed the 'Fit Type' from 'Fixed Count' to 'Fit Curve'. But now the Path is much shorter than the road it self.  And If I extrude the curve the road goes even longer and longer. Is there a way the road is as long as the path? How to install Chromium without snap? I just discovered that chromium will only be released as a snap package.  How can I continue to get chromium, without snap? Is this possible without building from source?  Notes:   Please let's keep to the question as stated - not "what do you have against snap?" I'm not asking how to remove snap (I realize that would break Ubuntu)... just how to use chromium as it is now, a deb.     Update  No, this is not a duplicate of that linked question. I don't need to know "why it's a snap". I want to know how to use it without snap.  Right now there is building from source, and some random PPA mentioned below. I hope someone can advise us of trustworthy alternatives.