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Interesting 55 Bountied Hot Week Month
-2 votes
0 answers
9 views

The limit value does not match the real value

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DaVinci N
  • 1
1 vote
0 answers
37 views

Find the derivative of $\frac{d}{dx}\left(\tan \left(\sqrt{x}\right)\right)$ - no chain rule

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Tyma Gaidash
  • 5,219
0 votes
0 answers
9 views

What are the conditions for cosets of a certain group to form a group themselves?

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Sammy Black
  • 16.8k
0 votes
0 answers
2 views

This is Stein fourier analysis. In section 3.3，I really don't understand how he gets to the final result(equation (4)),can someone explain in detail?

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cyz20030307
  • 1
10 votes
2 answers
84 views

Prove $\sum_{i,j:i<j} μ(E_{i} \cap E_{j} )=\infty$.

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Matematleta
  • 26.5k
2 votes
1 answer
80 views

Find a polynomial of the form $F(x,y,z)$ of degree $3$ such that $F(a,b,c) = 0 \pmod{5}$ iff $a,b,c= 0 \pmod{5}$

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Mike
  • 15.5k
-1 votes
0 answers
12 views

Second inner product.

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finn32497
  • 1
0 votes
1 answer
9 views

Properties of conformal maps

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Binxu Wang 王彬旭
  • 979
0 votes
0 answers
3 views

Are there any theorems about the restriction of a partial order?

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Ypbor
  • 167
1 vote
0 answers
7 views

definition of closed immersions of schemes

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Adam
  • 267
1 vote
2 answers
7 views

Must a certain continuous map have 0 in its image, given that its restriction to the unit sphere is homotopic to the identity?

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Ruy
  • 13.6k
0 votes
0 answers
5 views

Find a process $\left(A_{n}\right)_{n}$ such that $\left(\sum^{n} X_{i}\right)^{2}-A_{n}$ is a martingale.

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Stochastichelp
  • 175
0 votes
1 answer
19 views

$u$ be the sol of $\Delta u+ a_i(x)\frac{\partial u}{\partial x_i}= f(x)$ if $f\geq 0$ then u is constant and $f=0$

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JackT
  • 3,496
2 votes
2 answers
1k views

Semi-Infinite String equation

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CommunityBot
  • 1
0 votes
3 answers
30 views

Let $A\in\mathbb{R}^{2\times 2}$ be such that $\det(A)=d\ne0$ and $\det(A+d\cdot\text{Adj}(A))=0$. Evaluate $\det(A-d\cdot\text{Adj}(A))$.

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Sourav Ghosh
  • 4,014
0 votes
1 answer
14 views

Origin of a term in an inequality.

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M. Logic
  • 1,175
0 votes
0 answers
7 views

Exercise on continuous functions, analysis 1

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Brandon Araya
  • 1
0 votes
0 answers
4 views

Elliptic regularity with right-hand side in $H^{-1/2}$

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Numa
  • 63
0 votes
0 answers
9 views

When we calculate the irr, how to decide the initial range of irr?

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Paul
  • 1
0 votes
0 answers
5 views

Evaluate/asymptotic of the sum $\sum_{a = 1}^{L \left({N}\right)} \left({- 1}\right)^{\left\lfloor{N/\left({2\, a + 1}\right)}\right\rfloor}$

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Lorenz H Menke
  • 729
0 votes
1 answer
8 views

Almost Sure Convergence of a Random Variable

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Jason
  • 15k
0 votes
0 answers
14 views

Why is "More Data Better than Less Data"?

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stats_noob
  • 1,692
1 vote
0 answers
10 views

Elementarily equivalent models of arithmetic that are not isomorphic.

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ngc1300
  • 493
0 votes
1 answer
907 views

Find the center of mass of a quarter circle given by $\sqrt{r^2−x^2}$, $x\in[0,r]$

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CommunityBot
  • 1
0 votes
0 answers
41 views

Are there more real numbers in the interval $[1,\infty)$ than in the interval $(0,1]$? Or not?

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dxiv
  • 68.4k
0 votes
1 answer
22 views

Function class consisting of gradients of real-valued convex functions

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max_zorn
  • 4,477
0 votes
0 answers
18 views

What is the difference between the principal square root of $x$ and $x^{1/2}$?

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unloadedmaterial
  • 1
0 votes
1 answer
28 views

For what values of $p>0$ is $\lim_{n\rightarrow\infty}\int_0^\infty\frac{(1-\frac{x}{n})^ne^x}{n^p}=0$?

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Przemysław Scherwentke
  • 13.4k
0 votes
0 answers
5 views

Conditional distribution of one of the two exponential random variables, given one is smaller than the other

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Tony B
  • 1,922
0 votes
1 answer
19 views

Pullback is not exact

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Hank Scorpio
  • 2,159
0 votes
0 answers
4 views

Are we able to Compare the Fisher Information of Two Variables?

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stats_noob
  • 1,692
0 votes
0 answers
7 views

can we always get the variables of a system of linear equations given the system is valid?

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A Farmanbar
  • 115
3 votes
0 answers
26 views

Calculation on Riemannian manifolds

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kid111
  • 369
1 vote
0 answers
50 views

Prove that if $y \neq 0$ and $n$ is odd, then $x^n+y^n=(x+y)^n$ only if $x=0$ or $x=-y$ (Spivak's Calculus, Ch. 11)

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evianpring
  • 1,655
0 votes
0 answers
9 views

Homology of the complement of a simple closed curve in a surface

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stupid_question_bot
  • 643
5 votes
0 answers
23 views

The coupon collector's most collected coupon

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Brocellous
  • 133
3 votes
2 answers
105 views

Combinatorial interpretation of Euclid's form for even perfect numbers

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Alejo
  • 49
0 votes
0 answers
14 views

Cardinal of a set (proof verification)

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Celine Harumi
  • 2,347
4 votes
1 answer
98 views

Why this partial function is not computable?

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Mitchell Spector
  • 8,561
0 votes
0 answers
19 views

I cannot prove that $T$ is diagonalizable $\Rightarrow$ $T|_{V_1},T|_{V_2},\dots,T|_{V_r}$ are diagonalizable.

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tchappy ha
  • 6,081
-1 votes
0 answers
15 views

consider the following relation on the set of positive integers.

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شجاع المطيري
  • 1
1 vote
1 answer
14 views

Maximality of matching after contracting an odd cycle in a graph

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Misha Lavrov
  • 113k
2 votes
0 answers
28 views

An interesting recurrent equality, possibly easier to solve in its differential form?

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Nen
  • 455
1 vote
0 answers
83 views
+50

Prove Kolmogorov's strong law of large numbers from Breiman ergodic theorem

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RobPratt
  • 33k
6 votes
1 answer
3k views

Bayesian Interpretation for Ridge Regression and the Lasso

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CommunityBot
  • 1
0 votes
1 answer
21 views

How to linearize a state space equation with higher order $>2$?

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RobPratt
  • 33k
0 votes
0 answers
16 views

For a compactly supported, continuously differentiable function $f$, do we have $\frac{f(x+h)-f(x)}{h}\to f'(x)$ uniformly?

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jk001
  • 717
2 votes
0 answers
21 views

"Spanning" of solutions of ordinary differential equations

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Alp Uzman
  • 6,864
2 votes
0 answers
35 views

Help showing that two sets are equal.

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Logi
  • 485
1 vote
0 answers
16 views

Why does the following remark on probability space not work on infinite, yet countable, sets?

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DomM
  • 11
2 votes
1 answer
20 views

Proof of Wronskian relation using induction

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Binxu Wang 王彬旭
  • 979
1 vote
1 answer
41 views

The derivative of a semialgebraic map is semialgebraic

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KReiser
  • 49.7k
6 votes
0 answers
47 views

Why does Galois theory most naturally take place in the context of fields?

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D.R.
  • 5,674
3 votes
1 answer
36 views

On the number of roots of $p(z,\bar z)$

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dxiv
  • 68.4k
1 vote
0 answers
39 views

Proof from Lang’s Basic Mathematics

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Robert Shore
  • 16.9k
3 votes
1 answer
22 views

What do the elements of the chains of a simplicial complex represent?

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Sammy Black
  • 16.8k
1 vote
0 answers
19 views

Global Langlands for tori?

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Tian An
  • 777
1 vote
0 answers
31 views

Is there a function $f$ from reals to reals such that every non-vertical line intersects $f$ infinitely many times?

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user107952
  • 13.3k
1 vote
1 answer
13 views

Conditioning in Event Language VS Proposition Language

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Graham Kemp
  • 119k
2 votes
0 answers
31 views

Why is $\int_{0}^{2\pi} \int_0^{2\pi} \frac{\ln(21-4(\cos x+\cos y+\cos(x+y)))}{2\ln(9/2)}\frac{dx}{2\pi} \frac{dy}{2\pi}$ almost $1$?

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Blue
  • 69.2k
1 vote
1 answer
29 views

An inequality: from the complex to the real case.

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Kavi Rama Murthy
  • 301k
0 votes
0 answers
34 views

How to proof this formula about Euler constant: $\gamma=\int_0^1\frac1{x+1}\sum\limits_{v=0}^\infty x^{2^v-1}dx$

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Tyma Gaidash
  • 5,219
1 vote
0 answers
11 views

Direct sum of small modules is small, also direct summands of small modules are small.

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Sok
  • 333
3 votes
0 answers
33 views

What' s the asymptotic behaviour of this integral?

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Gary
  • 19.7k
1 vote
0 answers
25 views

Determine if $f(x,y)=e^{-xy}\cos(2x)\cos(y)$ is integrable via Fubini

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Gary
  • 19.7k
2 votes
0 answers
21 views

Calculating the angle between 2 one-sided surfaces.

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vaana
  • 21
1 vote
0 answers
12 views

Exemple where tower property of conditional expectation is NOT verify

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X0-user-0X
  • 53
1 vote
1 answer
32 views

Meaning of symbol in probability theorem

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Eevee Trainer
  • 29.5k
1 vote
0 answers
14 views

Approximating an open set in measure with another open set whose boundary has zero measure

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Nick Sun
  • 31
1 vote
0 answers
21 views

Quadratic Reciprocity as an Analytic Statement

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modperspec
  • 635
0 votes
1 answer
24 views

Proof that markov chain equilibrium using Farkas' lemma

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Yuval Peres
  • 10.5k
8 votes
0 answers
98 views

Collatz conjecture but with $n^2-1$ instead of $3n+1.$ Does the sequence starting with $13$ go to infinity?

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lulu
  • 62.6k
0 votes
0 answers
26 views
+100

Boundedness of singular integral operator on normalized bump functions implies boundedness on Schwartz functions controlled by suitable seminorms

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Sqrt
  • 26
1 vote
0 answers
27 views

Proof: $C^\infty[0,1]$ is dense in $L^2[0,1]$

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X0-user-0X
  • 53
0 votes
0 answers
9 views

What set of matrices $X,Y$ satisfy $X \circ Y = X P Y$ for at least one permutation matrix $P$?

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Galen
  • 1,304
0 votes
0 answers
15 views

How many integer values of $m\in[-20;22]$ are there such that the equation $\log_2(x^2+m+x\sqrt{x^2+4})=(2m-9)x-1+(1-2m)\sqrt{x^2+4}$ has a solution?

user avatar
Lê Thành Đạt
  • 4,008
3 votes
1 answer
24 views

Are invertibly cobordant manifolds diffeomorphic

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kamills
  • 1,696
0 votes
0 answers
10 views

Find $\mathbb{E}[\hat{\alpha}]$. Suggest a new estimate $\check{\alpha}$ of $\alpha$ which is unbiased, such that $\mathbb{E}[\check{\alpha}]=a$

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Mugge
  • 1
1 vote
0 answers
15 views

General form of rank $2$ tensor invaiant under certain rotations

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ContraKinta
  • 677
0 votes
1 answer
11 views

Theorem of the Maximum for discrete sequences of constraint sets?

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evencoil
  • 321
0 votes
0 answers
17 views

Goldbach Conjecture and Triangular Number

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MD SHAHIDUL ISLAM
  • 1
4 votes
0 answers
86 views
+200

Does Lipschitz-kind "non-scalar ODEs" and PDEs could stand having finite-duration solutions?

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Joako
  • 741
1 vote
0 answers
28 views

Hyperplane contains an inversible matrix

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Ben Grossmann
  • 203k
0 votes
0 answers
6 views

Help on this article of Centralizers of Groups

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Rodolfo Ferreira de Oliveira
  • 407
2 votes
0 answers
11 views

Can we calculate the opponent's hidden values in this statistical battle?

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Avestura
  • 129
0 votes
0 answers
16 views

Number of functions under some conditions

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Sammy Black
  • 16.8k
1 vote
0 answers
9 views

Decomposing a big and nef divisor into ample + effective

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Bun
  • 93
2 votes
0 answers
38 views

Find asymptotic variance of moment estimator

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Lifeni
  • 655
0 votes
0 answers
5 views

Using multivector residue theorem to evaluate multiple integrals

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Ricardo Ochel
  • 1
3 votes
0 answers
9 views

Divisibility of unitriangular matrices over a field of characteristic 0

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square17
  • 123
0 votes
0 answers
8 views

About the condition $1-\alpha_1(f^n(x),f^{10+m}(x))\beta_1(f^{n+1}(x),f^{m+1}(x)) R\neq 0$

user avatar
Amer Bhat
  • 1
1 vote
0 answers
8 views

Embedded arcs staying embedded after squaring.

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l_frost
  • 131
5 votes
4 answers
168 views

Differentiation without quotient rule

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Hans Engler
  • 14.1k
0 votes
0 answers
10 views

Continuity of Taylor remainder for a multivariate $C^1$ function

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Olivia Cannon
  • 1
0 votes
2 answers
38 views

Why is addition not commutative under PM's notion of relation number?

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Thomas Ferrari
  • 21
3 votes
0 answers
19 views

How to make sense of SDE notation

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focusonimprove333
  • 147
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