8,771 reputation
22040
bio website gottwurfelt.wordpress.com
location San Francisco, CA
age 30
visits member for 4 years, 2 months
seen 53 mins ago

Quantitative analyst and math blogger.


21h
reviewed Approve suggested edit on Subgroup generated by a set
1d
comment Proving $\frac{1}{\sin^{2}\frac{\pi}{14}} + \frac{1}{\sin^{2}\frac{3\pi}{14}} + \frac{1}{\sin^{2}\frac{5\pi}{14}} = 24$
If I'm not mistaken, this generalizes to give $\sum_{k=1}^n \csc^2 (k\pi/(2n+1)) = 2n(n+1)$, with $n = 3$ being the original question.
2d
revised How many ways are there to write 675 as a difference of two squares?
retagged
2d
answered Finding a recursive formula for a number
Sep
15
comment Random walk on a finite square grid: probability of given position after 15 or 3600 moves
For a related blog post see John Cook's post.
Sep
12
awarded  Autobiographer
Sep
11
answered Odds for randomly assigning a men-only group in a team working assignment
Sep
5
awarded  Necromancer
Sep
4
answered Approximating Logs and Antilogs by hand
Sep
3
awarded  Enlightened
Sep
3
awarded  Nice Answer
Aug
26
reviewed Reject suggested edit on How to find the remainder when the following series is divided by 12?
Aug
15
comment Is there a name for the function $\max(x, 0)$?
It should be noted that the negative part is, in fact, a positive number. For example the negative part of -3 is 3.
Aug
11
reviewed Approve suggested edit on optimization tag wiki
Aug
5
comment Asymptotic behavior of $\sum\limits_{k=1}^n \frac{2^k}{k}$
Call your sum $S_n$. Let $T_n = S_n/2^n$; then it's not hard to show that $T_1 = 1$, $T_n = T_{n-1}/2 + 1/n$. You want to show $T_n \sim 2/(n+1)$. Not sure this helps.
Aug
5
awarded  Good Answer
Jul
21
awarded  Yearling
Jul
17
reviewed Approve suggested edit on A strange puzzle having two possible solutions
Jul
16
comment Probability of Random Variable Minus Random Variable
There are quantitative bounds on the approximation such as the Berry-Esseen inequality, but those are almost surely beyond the scope of the course the poster is taking.
Jul
7
awarded  Nice Answer