Reputation
9,725
Next privilege 10,000 Rep.
Access moderator tools
Badges
4 16 47
Newest
 Enlightened
Impact
~157k people reached

1d
revised Enumerating Bianchi circles
add paragraph, vis tag
1d
comment Is there any formal or scientific use for a base 7 numeral system?
Yes, in hexagonal image processing, but I'm not familiar with the details.
2d
asked Enumerating Bianchi circles
Apr
21
answered If complex numbers can be represented as vectors, why can't we define $2$-dimensional vector division just as complex division?
Apr
10
comment What is the general solution to $\sin\theta=\frac12$?
Why do you say your solution is wrong?
Mar
31
comment Some clarifications on analytic continuation of Riemann's Zeta function on $\frac 1 2$
For the first question, see math.stackexchange.com/questions/947158/… and math.stackexchange.com/questions/1082139/…
Mar
24
revised For what $n$ does $[\log_21]+[\log_22]+[\log_23]+\dotsb+[\log_2n] = 1538$?
rolled back to a previous revision
Mar
4
comment Prob. 5 in Exercises after Sec. 17 in Munkres' TOPOLOGY, 2nd ed.: How to prove this result in a general ordered set?
Try a few examples of intervals in different ordered sets. For which does equality hold? What is the pattern?
Mar
2
comment Can $10^{2k+1}+ 1$ be a perfect square?
Regarding recent edits, if you'd like to ask about $3^n$, please ask a new, separate question.
Mar
2
revised Can $10^{2k+1}+ 1$ be a perfect square?
rolled back to a previous revision
Feb
27
comment Why can you chose how to align infinitely long equations when adding them?
Arbitrary rearrangements do require absolute convergence to preserve the sum. But to address the OP, shifting only requires convergence. Also, adding series term-by-term only requires convergence. Moreover, some common summation methods for divergent series also respect these two operations, making them "stable" and "linear". Cesaro summation and Abel summation are good examples. So the operations are surprisingly forgiving!
Feb
27
comment $f$ convex, $\lim_{x\to\infty}\frac{f(x)}{x}=0$, then $f$ is constant
This is a slightly stronger result than math.stackexchange.com/questions/518091, and Henning Makholm's approach there works here as well.
Feb
27
answered Can $10^{2k+1}+ 1$ be a perfect square?
Feb
24
comment NP-hard optimization problems for which approximations would be useless?
Produce a proof certificate for [insert famous conjecture] containing as few errors as possible?
Feb
23
comment Why line integral of f(x.y)=(x.y) is not zero along the circle?
How did you compute the integral?
Feb
23
revised Find the numbers that have an inverse modulo 11
title
Feb
22
revised Prove the $n$th Fibonacci number is the integer closest to $\frac{1}{\sqrt{5}}\left( \frac{1 + \sqrt{5}}{2} \right)^n$
transcribe images; place expression in title
Feb
22
comment Showing that $f_n$ is the number closest to $\frac{1}{\sqrt{5}}(\frac{1+\sqrt{5}}{2})^n$
Whoops, I was a little too quick to answer this question. Will mark the duplicate.
Feb
22
answered Showing that $f_n$ is the number closest to $\frac{1}{\sqrt{5}}(\frac{1+\sqrt{5}}{2})^n$
Feb
20
revised How to calculate $\exp(-x)$ using Taylor series
significant typo