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2h
comment If $aH = Hb$ for all $a,b \in G$, prove that $aH = Ha$.
A much better question is, if $aH=Hb$ for some $a$ and $b$ in $G$, then $aH=Ha$.
3h
comment What's the differences between multi variable and vector calculus
When I think of vector calculus, I think of the integral theorems (Green's, Divergence, Stokes'). When I think of multivariable calculus, I think of the material coming before that (partial derivatives, multiple integrals, spherical coordinates and such). But I don't know whether other people see it that way.
3h
comment Does the following conjecture regarding the Riemann Zeta function hold?
Sorry, I don't do chat.
6h
comment Does the following conjecture regarding the Riemann Zeta function hold?
"One of the conditions"? It's the only condition on $s$ that I can see. What are the other conditions?
8h
comment A question about the degree of sin(2π/n) over the rationals
What do you think the dimension of $V\oplus W$ is, in terms of the dimensions of $V$ and $W$? And what do you mean by ${\bf Q}_n$?
8h
comment Hearts Game Word Problem
Are we assuming all scores are non-negative integers? This seems not to be stated in the body of the question.
12h
comment Does the following conjecture regarding the Riemann Zeta function hold?
The condition on $s$ is $s$ real and $s<-1$?
1d
comment Does the following conjecture regarding the Riemann Zeta function hold?
OK, then, what does it mean for two functions of $s$ to be approximately equal? Arnold Ross used to ask, "What is an approximation to 5?", and he would answer, "Any number except 5."
1d
comment Number of games required such that two arbitrary players play together and against each at least once.
Maybe you could calculate it by hand for some small values of $N$, then look up your answer in the Online Encyclopedia of Integer Sequences.
1d
comment Does the following conjecture regarding the Riemann Zeta function hold?
I'm not sure what you mean by those two wavy lines. Do you mean asymptotic, as $s\to\infty$?
Jul
4
comment Finding the intersections from most intervals
A data structure is not an algorithm. You are "looking for a data structure". That's coding, not math.
Jul
4
comment In how many ways can the committee be selected if the girls must include either Roberta or Priya but not both?
Instead of posting 3 (or more!) related questions, post one question, wait until you get an answer you understand, then try to solve the other questions on your own; if this doesn't work, post one more question, and iterate the procedure.
Jul
4
comment Permutations and Combinations Tricky Question
There's another way Browns can be together: two together, two elsewhere not together.
Jul
4
comment Finding the intersections from most intervals
Sounds like you have a question for a coding site, not a mathematics site.
Jul
4
comment How does Graham knows his number is really the upper bound to the dimension problem?
The first step is to read Graham's proof, and see whether you can understand it. If you can, great, you win. If you get pretty far into it, then get stuck somewhere, come back and ask a specific question about the place where you get stuck. And if you look at the proof and you can't understand any of it, hire a tutor to take you through it --- there's nothing we can do for you here.
Jul
4
comment $n^2(n-1)\sigma(n)=0 \mod 12$, where $\sigma(n)$ is the sum of divisors function
...and a similar "pair the divisors" argument can be carried out in this case.
Jul
4
comment $n^2(n-1)\sigma(n)=0 \mod 12$, where $\sigma(n)$ is the sum of divisors function
If $n=6r+4$, then $12$ divides $n^2(n-1)$, and we're done. Ditto if $n=6r$. If $n=6r+2$, then $4$ divides $n^2(n-1)$, so it suffices to show $3$ divides $\sigma(n)$. This is seen to be true by pairing each divisor $d$ of $n$ with $n/d$, and showing that these two divisors sum to a multiple of $3$. If $n=6r+1$ or $n=6r+3$ then $6$ divides $n^2(n-1)$, so it suffices to show that $\sigma(n)$ is even. That's true because $n$ has an even number of divisors, each of which is odd --- except if $n$ is a perfect square. But in that case, $n=12r+1$, and we win. This leaves the case $n=6r+5$....
Jul
4
comment limit of a complex expression
I'm not sure the thing has a limit. Let's look at a similar but much simpler problem: $\lim_{r\to\infty}(1+e^{\pi ir})^{1/r}$. It seems to me that there are arbitrarily large $r$ for which the expression is zero, and other $r$ for which it is $2^{1/r}$, converging to 1.
Jul
4
comment Fractional part of $n\alpha$ is equidistributed
I think what you are trying to do is prove Weyl's criterion. You know the sum converges to the integral for exponential functions, and you know the exponential functions are dense in the continuous functions, so you put these together to make an argument that the sum converges to the integral for continuous functions. The argument should be in any source that gives a proof of Weyl.
Jul
4
comment Considering bank-interest and inflation rates to calculate remaining money in the account
I told you what kind of equation it is. That gives you plenty of keywords to search on. It's also in many many discrete math textbooks, in the chapter(s) on recurrence relations (another search term!). I sometimes teach the topic from these notes: rutherglen.science.mq.edu.au/wchen/lndmfolder/dm16.pdf