107 reputation
4
bio website
location Shanghai, China
age 20
visits member for 2 years, 9 months
seen Jul 24 at 3:38

CS student.


Sep
24
awarded  Autobiographer
Jun
23
accepted Path-connected and locally connected space that is not locally path-connected
Jun
23
comment Path-connected and locally connected space that is not locally path-connected
Ingenious! Except there's one little problem with your proof of the lemma. The set $U_b = b \cup (A \setminus B)$ may not be open, since it's possible that $B$ is not countable. So we should choose a countable subset $B_0$ of $B$ which has more than 1 element, and let $U_b = b \cup (A \setminus B_0)$.
Jun
23
comment Path-connected and locally connected space that is not locally path-connected
Thanks. But that site doesn't have an example having these properties.
Jun
22
asked Path-connected and locally connected space that is not locally path-connected
Oct
7
revised Definition of $\pi$, $\lim_{n \to \infty}{n \sin(180^o/n)}$
add tag calculus
Oct
7
asked Definition of $\pi$, $\lim_{n \to \infty}{n \sin(180^o/n)}$
Oct
4
comment Please prove: $ \lim_{n\to \infty}\sqrt[n]{\frac{1}{n!}} = 0 $
@mick: I'm so sorry to ask so vaguely, but Alfred just happened to show what I want to know. It is exactly the answer on my book but more detailed. And now I can understand the book's answer.
Oct
4
comment Please prove: $ \lim_{n\to \infty}\sqrt[n]{\frac{1}{n!}} = 0 $
@robjohn: Thank you for telling me this. I'll post more next time I ask.
Oct
3
accepted Please prove: $ \lim_{n\to \infty}\sqrt[n]{\frac{1}{n!}} = 0 $
Oct
3
asked Please prove: $ \lim_{n\to \infty}\sqrt[n]{\frac{1}{n!}} = 0 $
Sep
16
awarded  Student
Sep
16
awarded  Scholar
Sep
16
accepted A Dedekind infinite set has a countably infinite proper subset
Sep
16
awarded  Editor
Sep
16
revised A Dedekind infinite set has a countably infinite proper subset
added 9 characters in body
Sep
16
asked A Dedekind infinite set has a countably infinite proper subset