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39m
answered Why is $\vec{s}=\frac{\vec{r}}{V^\frac{1}{3}} \Leftrightarrow d\vec{s}=\frac{d\vec{r}}{V}$?
16h
comment Proving ($\left|\left|Ax\right|\right| = \left|\left|x\right|\right|$, for all $x\in\mathbb{C}^n$) $\implies A$ is unitary
Do you mean $x \in \mathbf{C}^n$ where $n$ is the dimension of your matrix? (and you are assuming $A$ is square?)
22h
answered If there's only two infinities, why isn't Calculus affected?
1d
answered what is $e$ really? what is its meaning?
1d
comment Cantor set representation
My point is that it's not a definition: it's just an equation that $C$ satisfies.
1d
comment Cantor set representation
I'm not entirely sure it's suitable to call it a definition. At the very least, a definition would require some additional stuff (e.g. $C = \varnothing$ and $C = \mathbf{R}$ both satisfy this formula)
1d
answered Idempotents in $\mathbf{CRing}$
1d
comment If a function is continuous on $\mathbb R,$ does it follow that it is uniformly continuous on $(-1,1)?$
@justin: Doesn't it follow immediately from the definition?
1d
comment How to factorise a number in $\mathbb {Z}[\sqrt {-5}]$?
And also I had been expecting a clear statement/confirmation of what you were looking for after my query, at which point I would have considered adding more, although it never really came.
1d
revised basic question regarding the definition of sheaf of rings
added 89 characters in body
1d
comment basic question regarding the definition of sheaf of rings
@user: IMO, both exercises are really the same exercise; I'm not sure one is any harder than the other. But I put both because maybe the first one is easier to think about.
1d
answered How to show $\sqrt{p}$ is not in $\mathbb{Q}_p$?
1d
comment In Texas Hold'em poker, is the ranking according to chance of beating 1 opponent's hand the same as according to beating multiple opponents?
@David: What you're missing is the difference between the mean and the variance. Having a better mean means you do better on average; but if you have a very low variance, that just means you consistently place somewhat above average, and almost never all the way at the front of the pack, which is terrible if the only thing that matters is whether or not you come in first. (unless, of course, your mean is hugely better than everybody else's mean)
2d
answered basic question regarding the definition of sheaf of rings
2d
answered What's the dimension of $\mathbb C$ as a vector space over $\mathbb{R}$?
2d
answered How to prove properly that $\mathbb{N \times N}$ $\rightarrow$ $\mathbb{N}$ : $(p,q) \rightarrow \frac{(p+q)(p+q+1)}{2} +q$ is a bijection?
2d
comment Existence of dual basis in Algebraic Number Theory
Please put the content of your question on this site, rather than in a pdf on another site.
2d
awarded  Nice Answer
2d
comment How to prove the lower bound of $\frac{x^2}{\sin^2x}$?
One of the common tricks to show $f(x) \leq g(x)$ identically on $[a,b]$ is to show $f(a) \leq g(a)$ and $g'(x) - f'(x) \geq 0$ for all $x \in [a,b]$. If this works for this problem, you'll want to continuously extend the r.h.s. to be defined at $x=0$.
2d
comment How to prove the lower bound of $\frac{x^2}{\sin^2x}$?
@BigM: $+\infty \geq 1 + \pi^2/3$, so that's not actually a problem.