# Ways to answer mathematical posts

Mathematics is supposed to abstract the essential features of a situation. I have yet to see this done for the common task of answering a question about mathematics posted to the forum.

For questions of the form: "How do I do ... X ...?", I offer the following general general patterns.

Pattern 1: Re-direction
You don't want to do X. Whay you really should do is Y. Y is a lot simpler. Y is what a smart person like myself would do.

The wikippedia article on Z explains X. Or just Google on the words "Z X", you'll find thousands of references. That's what I did. (Of course I didn't read any of them to see if they actually answered your question.)

Pattern 3: Disambiguation
What you mean by "X"? Are your talking about "X1" or "X2" or some other kind of "X". You need to become an expert in order to ask a mathematical questions clearly. Why don't you study this awhile on your own?

Pattern 4: Suspicion
Is this a homework problem? What ways have you tried to do X. Show us your work. Sure it might take an hour or two to get all that typed up and submitted, but I have the time to wait.

Pattern 5: Let the computer do it
You might be able to do X, but I think it's very complicated and if I tried to do it, I'd probably make a mistake and look like an idiot. Why don't your try a Monte-Carlo simulation or put into Mathematica?

micromass
Staff Emeritus
Homework Helper
Why stop at answers?? Why not generalize the questions too??

Question type 1: The utterly clueless
Example: I want to solve the integral $\int_0^{2\pi}{\cos(x)dx}$. I tried

$$\int_0^{2\pi}{\cos(x)dx}=\left[\frac{\sin(x)}{x}\right]_0^{2\pi}=\frac{\sin(2\pi)}{2\pi}-\frac{\sin(0)}{0}=\sin-\sin=0$$

Wolfram alpha says I'm correct, but my professor says that it's wrong. Is my professor an idiot??

Question type 2: Too general questions
Example: I don't really understand quantum mechanics. Can anybody explain this too me??

Question type 3: Too specific questions
Example: I want to find the Q-cohomology group of the twisted etale sheaf. Perhaps we can use the vector bundle fibration with respect to the free group on 5 elements? Any ideas?

Question type 4: The lazy
Example: I want to find the roots to the polynomial $x^2+x+1=0$. Can anybody help me. This assignment is due in 1 hour. Please help me now!!

Evo
Mentor
Why stop at answers?? Why not generalize the questions too??

Question type 1: The utterly clueless
Example: I want to solve the integral $\int_0^{2\pi}{\cos(x)dx}$. I tried

$$\int_0^{2\pi}{\cos(x)dx}=\left[\frac{\sin(x)}{x}\right]_0^{2\pi}=\frac{\sin(2\pi)}{2\pi}-\frac{\sin(0)}{0}=\sin-\sin=0$$

Wolfram alpha says I'm correct, but my professor says that it's wrong. Is my professor an idiot??

Question type 2: Too general questions
Example: I don't really understand quantum mechanics. Can anybody explain this too me??

Question type 3: Too specific questions
Example: I want to find the Q-cohomology group of the twisted etale sheaf. Perhaps we can use the vector bundle fibration with respect to the free group on 5 elements? Any ideas?

Question type 4: The lazy
Example: I want to find the roots to the polynomial $x^2+x+1=0$. Can anybody help me. This assignment is due in 1 hour. Please help me now!!
LOL!!

I love the ones that say NEED HELP NOW!!!!! Then attach a photocopy of a long list of problems and say "be specific with your answers and put them in the following format..." Then an hour later "you people SUCK, I need these answers NOW!!"

D H
Staff Emeritus
Pattern 6: PhD level answer to a high school level question.
This question is trivially answered if you look at from the perspective of a Grothendieck topology1. Why didn't you use that approach?

1 I haven't the foggiest what a Grothendieck topology is. I used "Pattern 2: Googleation" to find the term. It wasn't hard; one nice thing about wikipedia articles is that so many of them rely heavily on Pattern 6.

However,
Pattern 4: Suspicion
Is this a homework problem? What ways have you tried to do X. Show us your work. Sure it might take an hour or two to get all that typed up and submitted, but I have the time to wait.
There's a good reason for this pattern. Some students cheat. Providing answers to the "do my homework for me" type posts is aiding and abetting, and it is a disservice to the teachers and to the many students who don't cheat.

Why stop at answers?? Why not generalize the questions too??

Question type 5: The Software Handicap

My company has recieved a contract to build the first commercial boron fusion reactor and I have been assigned to produce a detailed simulation of the fusion process and its effect on the containment chamber. How can I do this in an Excel spreadsheet?

I like Serena
Homework Helper
Question type 6: Nice problem!

The OP has a really interesting problem that triggers you to do some research.
You post back and he understands perfectly what you write and takes it to the next level.
To top it off he's really appreciative, which makes you smile.

Pattern 4: Suspicion
Is this a homework problem? What ways have you tried to do X. Show us your work. Sure it might take an hour or two to get all that typed up and submitted, but I have the time to wait.

There's a good reason for this pattern. Some students cheat. Providing answers to the "do my homework for me" type posts is aiding and abetting, and it is a disservice to the teachers and to the many students who don't cheat.

But it really does take that long take that long to enter the problem and the work. Surely that amount of effort deserves a helpful answer.

Pattern 7: is that a typo?
Sorry but your whole answer (and the answers offered by the other members) is wrong. Clearly when you wrote f/x) you meant f(x) but until you fix that typo we have to assume f is a variable and it's being divided by x.

Totally ignoring the fine answers already given, and the OP's acknowledgement of completion of the problem, this answer provides information that is already given, or at best, a new way to get the same answer.

micromass
Staff Emeritus
Homework Helper
But it really does take that long take that long to enter the problem and the work. Surely that amount of effort deserves a helpful answer.

Thinking about a problem, working out the solution, typing up a helpful answer takes just as long!! And we have nothing to gain with it, we do it in our free time! Surely that amount of effort deserves the courtesy to type up the work and to think a bit before posting.

epenguin
Homework Helper
Gold Member
Question type 6: Nice problem!

The OP has a really interesting problem that triggers you to do some research.
You post back and he understands perfectly what you write and takes it to the next level.
To top it off he's really appreciative, which makes you smile.

Question type 6a: Nice problem!

The OP has a really interesting problem that triggers you to do some research.
You post back and it falls into an echoless void, you never hear anything more. Or maybe something and reply to the reply falls into the void.

Except maybe the same OP posts another problem maybe in same general area, you post back and the same thing happens again.

Maybe after a bit of this you don't post back though. :grumpy:

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D H
Staff Emeritus
But it really does take that long take that long to enter the problem and the work. Surely that amount of effort deserves a helpful answer.
You should see the stuff that we mentors reject. Based on a real example:

anonymous user said:

## Homework Statement

The ﬁgures below show ... [majority of problem satement elided]
You may assume that gravity (g = 9.8 m/s2 )
is acting downward in the ﬁgure.

## Homework Equations

Conservation of Energy

## The Attempt at a Solution

Based on way the question is formatted, it was quite obvious that in this case the student simply copied the question from an e-book and pasted it into our homework template. The relevant equation was obviously the first thing that came to the student's mind. No attempt whatsoever at a solution. How much effort did that take? 30 seconds, maybe?

You should see the stuff that we mentors reject. Based on a real example:

Based on way the question is formatted, it was quite obvious that in this case the student simply copied the question from an e-book and pasted it into our homework template. The relevant equation was obviously the first thing that came to the student's mind. No attempt whatsoever at a solution. How much effort did that take? 30 seconds, maybe?

I didn't mean everybody, I only meant me :p

I like Serena
Homework Helper
Question type 6a: Nice problem!

The OP has a really interesting problem that triggers you to do some research.
You post back and it falls into an echoless void, you never hear anything more. Or maybe something and reply to the reply falls into the void.

Except maybe the same OP posts another problem maybe in same general area, you post back and the same thing happens again.

Maybe after a bit of this you don't post back though. :grumpy:

Yes, I've had that too! :rofl:

However, in one particular thread there were follow-ups by 2 different new posters!
So an echo-less problem turned out to be quite satisfying!

PAllen
Question type 2: Too general questions
Example: I don't really understand quantum mechanics. Can anybody explain this too me??

Since, in another thread, the issue of not many questions about discrete math came up, I'll add one with an example of this question type:

Can someone briefly explain the proof of the classification of finite simple groups?

twisted individuals.

collinsmark
Homework Helper
Gold Member
Question type 4a: The grammatically/punctuation/typing lazy.
Example:
hypothetical said:

## Homework Statement

find the magnitude F of 2 protons 1 m apart

## The Attempt at a Solution

when i try 2 simplify F=1/4piee0 1.6 10-19^2/1^2 i get 6.67577433610-29 but my teacher says z answer is 2.3010-28 ive trid putting n my calculator twice but i go z same answer gain do u think my calculator broken?

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