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5h
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.
5h
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.
6h
comment Permutations and Combinations Tricky Question
There's another way Browns can be together: two together, two elsewhere not together.
6h
comment Finding the intersections from most intervals
Sounds like you have a question for a coding site, not a mathematics site.
6h
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.
6h
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.
6h
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 $n=6r+5$....
6h
answered What is the intuition of conjugacy classes?
12h
awarded  group-theory
14h
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.
14h
answered Conjugacy Classes of a group G - Intuitive Understanding
15h
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.
15h
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
1d
comment Considering bank-interest and inflation rates to calculate remaining money in the account
Anyway, if I understand what you are asking, then the balance satisfies $a_0=35000$, $a_n=(1.01)a_{n-1}-(250)(1.01)^n$. This is a simple first order constant-coefficient inhomogeneous difference equation, solvable by the standard methods, and certainly solved on this website many times.
1d
comment Considering bank-interest and inflation rates to calculate remaining money in the account
You write that he puts 100 in another account with the same interest rate; why not just say he leaves 100 in the original account? You write the bank gives 350 interest, but I think you really mean the bank gives 1% interest. You write that he spends 250, but I think you mean he spends an amount that is equivalent, after taking inflation into account, to 250. It would be much easier to solve the question, if you would write what you actually mean, instead of writing something else.
1d
comment Fractional part of $n\alpha$ is equidistributed
The search term for what you are looking at is "Weyl criteria". The idea is that the exponential functions are dense in the continuous functions.
1d
comment Divisor sum function for integral values
The problem, as I have stated several times, is that you write that $\sum_{n\le x}d(n)$ is equal to $x\log x+(2\gamma-1)x+1/4$, which is patently false.
1d
comment open problems regarding functions
An earlier, related question is math.stackexchange.com/questions/238680/…
1d
answered open problems regarding functions
1d
comment Divisor sum function for integral values
What Chandrasekharan actually writes is, $$\sum_{n\le x}d(n)={1\over4}+x\log x+(2\gamma-1)x-\sum_{n=1}^{\infty}d(n)(x/n)^{1/2}F_1(4\pi(nx)^{1/2})$$ where $F_1=Y_1+(2/\pi)K_1$, where $Y_1$ and $K_1$ are Bessel functions.