Reputation
53,283
Next tag badge:
99/100 score
40/20 answers
Badges
2 38 63
Newest
 Enlightened
Impact
~411k people reached

7h
answered Is $P(W \geq z |V \geq y)=P(U-V \geq z |V \geq y)=P(U \geq z+y)$ correct?
1d
comment To prove that $G$ is the group the condition is not necessary $\forall a,b, c \in G(ba=ca\to b=c)$.?
They are not a finite semigroup @ThomasAndrews
1d
answered $\sigma$-algebra produced by a subclass of a class.
1d
revised Notation in sums
TeXification
1d
answered How to establish convergence and find limit of the sequence$(n+1)^{1/\ln(n+1)}$
Feb
10
answered Is it true that $|e^z|\le e^{|z|}$ for all $z \in \mathbb C$?
Feb
10
answered If $\mathbf{E}(e|x) = 0$, then $\mathbf{E}(h(x)e) = 0$ for any function $h(x)$
Feb
9
answered Non-Borel a.e limit of Borel functions
Feb
9
answered What it the fourier transform of laplacian and shifted funtion?
Feb
9
comment Does every positive integer appear in the digits of $2\cdot 0.1234567891011… $?
For $3C$ you could argue as follows: Write $n = 3n' + j$, $j \in \{0,1,2\}$. If now $n' = a_k \ldots a_0$ in base $10$, we can look for $10a_k \ldots a_0 0 $ in $C$ to find $3n'$. If $j = 1$, look for $10 a_k \ldots a_0 4 0$ in $C$, if $j = 2$, look for $10 a_k \ldots a_0 7 0$ in $C$
Feb
9
comment Is this operator a distribution?
... calculate $T\phi$ for a given $\phi \in C^\infty_0(\mathbf R)$.
Feb
9
comment Given any 40 people, at least four of them were born in the same month of the year
Because $3 \cdot 12 = 36 < 40$.
Feb
9
comment Hybrid equivalence of Polynomial-like maps
We want to have $\frac{\partial f}{\partial\bar z} = 1$ for $f(z) = \bar z$.
Feb
9
comment Name of and references for the equivalence relation $x \sim y :\Longleftrightarrow x^2 = y^2$
Note that, due to $$ x^2 - y^2 = (x-y)(x+y) $$ we have $x/\mathord\sim = \{x,-x\}$. So I do not think that $\sim$ is interesting. But, yes, $\mathbf R/\mathord\sim \cong \mathbf R^+_0$.
Feb
9
answered Hybrid equivalence of Polynomial-like maps
Feb
8
answered Does $\mathbb{P}$-a.s. convergence preserve independence?
Feb
5
comment How to prove that for all $k\in\mathbb N$, $h(kx)=kh(x)$ and $h(x+y)\le h(x)+h(y)$?
No, it's not. Just wanted to show that the scaling property follows even if $g$ does not have the triangle inequality
Feb
5
answered How to prove that for all $k\in\mathbb N$, $h(kx)=kh(x)$ and $h(x+y)\le h(x)+h(y)$?
Feb
5
comment True/false questions about minimal and characteristic polynomials of a matrix
$f_A$ is the characteristic polynomial? Then your 1. is wrong, cause the polynomial you give has degree 5, but $A$ is a $3$-matrix
Feb
5
answered How to go about proving dim(VxW) = dim V + dim W