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Oct
5
accepted Is the limit of the dual spaces the dual space of the limit?
Oct
5
comment Is the limit of the dual spaces the dual space of the limit?
Very nice. As far as I can tell, your argumentation is correct.
Oct
5
comment A property of homogeneous of degree p functions:
No, you haven't. Note that you're actually calculating the $n$-th derivative only in the first equation (where there's only a polynomial in $t$). In the second equation, you just use $d/dt = \sum dy/dt \partial/\partial y$ repeatedly, and don't try to calculate anything. (note $(d/dt)^n f = d/dt (d/dt)^{n-1} f$; now $(d/dt)^{n-1} f$ is a function, just like $f$ is; note that $f$ itself is left alone, and only $d/dt$ is rewritten in the second equation)
Oct
5
answered A property of homogeneous of degree p functions:
Oct
4
answered x / 3 + y /3 + z / 3 = (x + y + z) / 3?
Oct
4
revised Is the limit of the dual spaces the dual space of the limit?
Added clarification that I mean the algebraic dual space
Oct
4
comment Is the limit of the dual spaces the dual space of the limit?
@Ian: Thanks, I indeed meant the algebraic dual space. I'll add a note to this effect. Of course, the situation with continuous duals might also be interesting.
Oct
4
comment Probability of bit revelaed
I'd say that depends on the probability of the other bits to be 1.
Oct
4
asked Is the limit of the dual spaces the dual space of the limit?
Oct
4
answered In QR decomposition why is $(R^TR)^{-1}R^T = R^{-1}$
Sep
30
awarded  Explainer
Sep
15
comment Combinatorics (Yahtzee)
A large straight is "2-3-4-5-6". But it does not matter which of the dice is 2, which is 3, which is 4, and so on. It just matters that each of those numbers appears. The same is true for all others. In no single case does the score depend on the order.
Sep
15
comment Why is the expression $\underbrace{n\cdot n\cdot \ldots n}_{k \text{ times}}$ bad?
With the underbrace notation, it's not at all clear what $n^0$ is.
Sep
14
revised Write the Fourier series to $f(t)=|\sin t|$
Improved math formatting
Sep
14
comment Combinatorics (Yahtzee)
You seem to know a different type of Yahtzee than I do: In the version I know, the order doesn't matter (indeed, you throw all five dice at once, and they are indistinguishable, therefore there's no way to even establish an order).
Sep
14
answered Comparing the size of square roots
Sep
13
answered Set containing all rings!
Sep
7
answered How to find the outermost points in an ellipse?
Sep
7
comment Solve $n^4>3^n$
@shengy: Just take both sides to the power of $1/(4n)$.
Sep
7
answered Quantum mechanics, conmutative operators.