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Accepted answer and score of 40 or more. This badge can be awarded multiple times.

Awarded 3148 times.

Prove variance in Uniform distribution (continuous)

Awarded 18 hours ago

Clement C.

68.6k8 gold badges83 silver badges171 bronze badges

CW complexes and manifolds

Awarded Nov 19 at 7:12

Neal

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If $x^m=e$ has at most $m$ solutions for any $m\in \mathbb{N}$, then $G$ is cyclic

Awarded Nov 14 at 13:43

Andrea Mori

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How can I prove that all rational numbers are either terminating decimal or repeating decimal numerals?

Awarded Nov 13 at 20:19

Bill Dubuque

285k42 gold badges343 silver badges1.1k bronze badges

Why is determinant a multilinear function?

Awarded Nov 11 at 15:42

A.Γ.

30.5k4 gold badges51 silver badges83 bronze badges

Norm for pointwise convergence

Awarded Nov 11 at 9:56

t.b.

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In combinatorics, how can one verify that one has counted correctly?

Awarded Oct 27 at 15:55

awkward

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Is $\{\tan(x) : x\in \mathbb{Q}\}$ a group under addition?

Awarded Oct 26 at 18:46

user8268

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Proving that a Hölder space is a Banach space

Awarded Oct 24 at 12:33

jflipp

4,9361 gold badge18 silver badges14 bronze badges

Expansion of $(1+\sqrt{2})^n$

Awarded Oct 15 at 6:56

Jyrki Lahtonen

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subgroups of finitely generated groups with a finite index

Awarded Oct 14 at 15:56

Nuno

3,9171 gold badge33 silver badges30 bronze badges

Nontrivial subring with unity different from the whole ring?

Awarded Oct 13 at 3:53

Arturo Magidin

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Why are randomly drawn vectors nearly perpendicular in high dimensions

Awarded Oct 11 at 19:07

Did

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Sequence of monotone functions converging to a continuous limit, is the convergence uniform?

Awarded Oct 7 at 13:33

Etienne

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How do the floor and ceiling functions work on negative numbers?

Awarded Oct 5 at 2:55

amWhy

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6-letter permutations in MISSISSIPPI

Awarded Oct 3 at 14:10

svenkatr

6,1351 gold badge34 silver badges32 bronze badges

Compute the $n$-th power of triangular $3\times3$ matrix

Awarded Sep 23 at 18:42

Ian Miller

12.2k1 gold badge28 silver badges41 bronze badges

Differentiability implies continuity - A question about the proof

Awarded Sep 22 at 15:51

Ian

105k5 gold badges101 silver badges171 bronze badges

Proof of a formula involving Euler's totient function: $\varphi (mn) = \varphi (m) \varphi (n) \cdot \frac{d}{\varphi (d)}$

Awarded Sep 20 at 6:40

Cardboard Box

5,20128 silver badges46 bronze badges

What is a universal property?

Awarded Sep 18 at 23:15

beroal

2,57320 silver badges25 bronze badges

Why do we say "almost surely" in Probability Theory?

Awarded Sep 16 at 4:57

Calvin Khor

36.6k6 gold badges48 silver badges105 bronze badges

Unbiased Estimator for a Uniform Variable Support

Awarded Sep 7 at 22:57

Did

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Does an uncountable discrete subspace of the reals exist?

Awarded Sep 4 at 15:27

Carl Mummert

87k13 gold badges179 silver badges326 bronze badges

What are zero divisors used for?

Awarded Sep 4 at 12:56

Jyrki Lahtonen

143k31 gold badges309 silver badges745 bronze badges

Formal basis for variable substitution in limits

Awarded Aug 31 at 5:08

Christian Blatter

233k14 gold badges206 silver badges491 bronze badges

Show that $\int_0^{\pi/3}\arccos(2\sin^2 x-\cos x)\mathrm dx=\frac{\pi^2}{5}$

Awarded Aug 30 at 19:48

Zacky

30.8k2 gold badges102 silver badges187 bronze badges

Is there an easy way to see associativity or non-associativity from an operation's table?

Awarded Aug 20 at 14:03

MJD

68.1k44 gold badges311 silver badges627 bronze badges

What is the idea behind distributions?

Awarded Aug 20 at 3:37

Daniel Smania

8,8821 gold badge10 silver badges33 bronze badges

Fundamental group of the special orthogonal group SO(n)

Awarded Aug 18 at 17:21

Eric O. Korman

20.1k3 gold badges60 silver badges96 bronze badges

Showing $\frac{\sin x}{x}$ is NOT Lebesgue Integrable on $\mathbb{R}_{\ge 0}$

Awarded Aug 16 at 9:06

glebovg

10.5k2 gold badges37 silver badges61 bronze badges

Fourier transform of the indicator of the unit ball

Awarded Aug 11 at 17:43

Daniel Fischer

212k19 gold badges310 silver badges440 bronze badges

Why have we chosen our number system to be decimal (base 10)?

Awarded Aug 10 at 23:00

Andrey Rekalo

8,0844 gold badges50 silver badges43 bronze badges

All real functions are continuous

Awarded Aug 6 at 23:31

Carl Mummert

87k13 gold badges179 silver badges326 bronze badges

Can $\ln$ be written as a ratio of polynomials?

Awarded Aug 2 at 17:23

Ryszard Szwarc

46.9k3 gold badges22 silver badges65 bronze badges

Grothendieck's yoga of six operations - in relatively basic terms?

Awarded Aug 1 at 21:49

Roland

13.4k1 gold badge40 silver badges41 bronze badges

What is the difference between the gradient and the directional derivative?

Awarded Aug 1 at 15:11

tabstop

1,91312 silver badges9 bronze badges

Presentation $\langle x,y,z\mid xyx^{-1}y^{-2},yzy^{-1}z^{-2},zxz^{-1}x^{-2}\rangle$ of group equal to trivial group

Awarded Jul 30 at 23:36

PseudoNeo

10.5k36 silver badges71 bronze badges

Finite Groups with exactly $n$ conjugacy classes $(n=2,3,...)$

Awarded Jul 24 at 21:46

Qiaochu Yuan

477k55 gold badges1.1k silver badges1.5k bronze badges

What does the word "let" mean in mathematics?

Awarded Jul 24 at 10:36

Joe

24.1k4 gold badges61 silver badges109 bronze badges

Gauss-divergence theorem for volume integral of a gradient field

Awarded Jul 24 at 9:38

achille hui

126k7 gold badges189 silver badges366 bronze badges

Integer solutions to $x^3=y^3+2y+1$?

Awarded Jul 12 at 8:30

A. Pongrácz

7,5282 gold badges19 silver badges32 bronze badges

Show that $11^{n+1}+12^{2n-1}$ is divisible by $133$.

Awarded Jul 11 at 22:10

Ayman Hourieh

41k5 gold badges109 silver badges165 bronze badges

Why is it so difficult to answer such a basic question in this field? ("Basic Manifold Theory" by Yukio Matsumoto.)

Awarded Jul 10 at 12:00

Timmathy

94310 silver badges24 bronze badges

What is "multiplication by juxtaposition"?

Awarded Jul 6 at 16:41

Gerry Myerson

188k14 gold badges237 silver badges410 bronze badges

The eigenvalues of a block matrix of the form $\pmatrix{B&C\\0&D}$

Awarded Jul 1 at 14:15

Jacob

2,6591 gold badge22 silver badges29 bronze badges

Why does dividing both sides of this system of equations to each other yields infinite "incorrect solutions"?

Awarded Jun 28 at 9:26

dxiv

78.1k6 gold badges70 silver badges128 bronze badges

What are some applications of Chebotarev Density Theorem?

Awarded Jun 22 at 22:53

Alex Youcis

57.4k9 gold badges137 silver badges203 bronze badges

Intuition for Fredholm operators?

Awarded Jun 20 at 9:07

levap

68k5 gold badges86 silver badges132 bronze badges

How to develop patience in mathematics?

Awarded Jun 16 at 23:05

Shaun♦

48.5k21 gold badges76 silver badges191 bronze badges

How to compute the smallest eigenvalue using the power iteration algorithm?

Awarded Jun 16 at 15:32

user7530

50.8k11 gold badges93 silver badges160 bronze badges

What can be said about the dual space of an infinite-dimensional real vector space?

Awarded Jun 15 at 13:35

Arturo Magidin

420k60 gold badges868 silver badges1.2k bronze badges

$L^1$ convergence gives a pointwise convergent subsequence

Awarded Jun 13 at 12:00

Disintegrating By Parts

92.5k6 gold badges77 silver badges172 bronze badges

When does the set enter set theory?

Awarded Jun 13 at 6:53

hmakholm left over Monica

293k25 gold badges443 silver badges709 bronze badges

Mean Value Theorem for complex functions?

Awarded Jun 11 at 11:01

Christian Blatter

233k14 gold badges206 silver badges491 bronze badges

Linear independency before and after Linear Transformation

Awarded Jun 9 at 11:11

Andrés E. Caicedo

82.1k10 gold badges233 silver badges368 bronze badges

Does the open mapping theorem imply the Baire category theorem?

Awarded Jun 8 at 11:07

Cloudscape

5,33618 silver badges37 bronze badges

Computing $\int_{0}^{\pi}\ln\left(1-2a\cos x+a^2\right) \, dx$

Awarded Jun 8 at 9:46

Ben

2,8942 gold badges31 silver badges37 bronze badges

Prove that $\int_0^1{\left\lfloor{1\over x}\right\rfloor}^{-1}\!dx={1\over2^2}+{1\over3^2}+{1\over4^2}+\cdots.$

Awarded Jun 7 at 17:34

Yiorgos S. Smyrlis

87.1k15 gold badges137 silver badges249 bronze badges

How to Prove a Programming Language is Turing Complete?

Awarded Jun 5 at 1:42

Giorgio Mossa

18.8k1 gold badge36 silver badges76 bronze badges

Norm of an inverse operator: $\|T^{-1}\|=\|T\|^{-1}$?

Awarded Jun 3 at 10:31

Jonas Meyer

56.1k9 gold badges216 silver badges310 bronze badges

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