Reputation
4,437
Top tag
Next privilege 5,000 Rep.
Approve tag wiki edits
Badges
9 24
Newest
 Nice Answer
Impact
~36k people reached

Nov
18
awarded  Nice Answer
Oct
23
revised why do odd magic squares have the same rank as their size?
added 10 characters in body
Oct
19
comment Compute $\partial_t \Gamma_{ij}^k$ under Ricci flow.
But say that $\partial_t g_{ij} = 0$ at the point $x = 0$, in our normal coordinate system. Then this does not say much about the value of $\partial_t g_{ij}$ at nearby points, so that in particular, the positional partial derivatives of $\partial_t g_{ij}$ could be non-zero.
Oct
19
comment Compute $\partial_t \Gamma_{ij}^k$ under Ricci flow.
Hm, no, since again, those properties only hold at a point. It's similar to how you do not have $f''(x) = (f'(x))'$.
Oct
19
comment Compute $\partial_t \Gamma_{ij}^k$ under Ricci flow.
Well, at the origin of the coordinate system, yes, and the first partial derivatives vanish at that point; see the Wikipedia article.
Oct
19
comment Find a positive natural number, $N$ such that $\frac{(n!)^2}{(2n)!}\leq \frac{1}{500} \forall n\geq N$
Remark: This looks rather similar to this question, posted slightly earlier.
Oct
19
comment Compute $\partial_t \Gamma_{ij}^k$ under Ricci flow.
You seem to be asking if this has something to do with whether or not one can choose normal coordinates, but according to the first line of the proof, this is exactly what is done.
Oct
19
answered Solving an inequality involving factorials and an exponent
Oct
14
comment Find the range of $f(x)=x/(3x^2−3x)$
What is the domain of the function? The reals except from $0$ and $1$?
Oct
14
revised Which one is larger asymptotically?
Fixed some formatting
Oct
13
revised Disjoint union topology vs Product topology
added 83 characters in body
Oct
13
revised Disjoint union topology vs Product topology
added 130 characters in body
Oct
13
answered Disjoint union topology vs Product topology
Oct
2
revised Basic question on the behavior of $\varepsilon$ in real analysis
Semantics
Oct
1
comment Basic question on the behavior of $\varepsilon$ in real analysis
Let's try two wildly different examples again. If $\varepsilon = 60$, then $2\varepsilon = 120$, which is bigger than $60$. On the other hand, if $\varepsilon = 1/60$, i.e. pretty small, then $2\varepsilon = 2/60 = 1/30$, which is bigger than $1/60$. No matter what $\varepsilon > 0$ is, $2\varepsilon$ will be bigger.
Oct
1
answered Basic question on the behavior of $\varepsilon$ in real analysis
Sep
30
comment Is $\mathbb R/R$ a partition of $\mathbb R$ given by some equivalence relation $R$?
And that in case that notation is new to OP, this means $x + \mathbb{Z} = \{ x + n \mid n \in \mathbb{Z} \}$.
Sep
30
answered Is $\mathbb R/R$ a partition of $\mathbb R$ given by some equivalence relation $R$?
Sep
13
comment Find all sets in sigma algebra generated by subsets A, B
Note that the sets you found are not necessarily distinct so that there need not be 16 sets.
Sep
9
revised Find all sets in sigma algebra generated by subsets A, B
added 14 characters in body