User Mark - Mathematics Stack Exchange

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2

5

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296

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character table of nonabelian group of order 21

representation-theory

jun 9 '12 at 16:06 Noah Snyder 4,316

2

4

votes

2

answers

517

views

Nonabelian semidirect products of order $pq$?

abstract-algebra group-theory

sep 10 '11 at 4:00 Community♦ 1

2

7

votes

2

answers

668

views

Number of automorphisms of a direct product of two cyclic $p$-groups

group-theory

mar 30 '11 at 13:35 David Speyer 18.7k

1

4

votes

4

answers

255

views

Show that $D_{12}$ is isomorphic to $D_6\times C_2$

group-theory finite-groups

jan 12 '12 at 4:33 Arturo Magidin 158k

3

4

votes

1

answer

316

views

Prove there is no element of order 6 in a simple group of order 168

group-theory

oct 11 '11 at 18:39 Jyrki Lahtonen 30.9k

4

6

votes

1

answer

291

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Why are these groups solvable?

homework group-theory

apr 30 at 4:59 Community♦ 1

2

6

votes

3

answers

700

views

Order of the centralizer of a permutation

group-theory permutations

nov 26 '11 at 21:46 Derek Holt 8,303

1

2

votes

1

answer

572

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Alternative way to prove a group of order 160 is not simple

group-theory finite-groups

jan 28 '12 at 20:11 Community♦ 1

1

3

votes

1

answer

1

kviews

No group of order 36 is simple

abstract-algebra group-theory finite-groups

aug 16 '11 at 4:53 Gobi 1,667

7

4

votes

2

answers

805

views

Challenging inequality: $abcde=1$, show that $\frac{1}{a}+\frac{1}{b}+\frac{1}{c}+\frac{1}{d}+\frac{1}{e}+\frac{33}{2(a+b+c+d+e)}\ge{\frac{{83}}{10}}$

algebra-precalculus inequality

dec 21 '11 at 8:13 user782220 599

2

4

votes

2

answers

291

views

Proving divisibility

discrete-mathematics divisibility

sep 4 at 3:26 I. J. Kennedy 1,267

11

22

votes

4

answers

600

views

How should I approach taking math tests?

soft-question

jul 11 '11 at 7:14 Mathemagician1234 3,744

2

6

votes

4

answers

227

views

A “fast” way for finding sum of the numbers from $1$ to $100$,which are not divisible by $3$ and $5$

elementary-number-theory

aug 28 '11 at 15:59 Willie Wong♦ 30.7k

2

8

votes

2

answers

934

views

Minimum degree of a graph and existence of perfect matching

graph-theory discrete-mathematics

dec 26 '11 at 21:15 Srivatsan 15.6k

1

3

votes

4

answers

836

views

Need an efficient algorithm to visit all nodes of a graph, revisiting edges and nodes is allowed

graph-theory trees recursive-algorithms searching

aug 5 '11 at 3:50 Veehmot 125

22

63

votes

7

answers

2

kviews

Why do people use “it is easy to prove”?

soft-question math-history proof-writing

apr 28 '12 at 17:41 J. M. 38.9k

20

28

votes

5

answers

4

kviews

Understanding Gödel's Incompleteness Theorem

logic incompleteness

nov 1 at 6:48 Holdsworth88 3,470

6

3

votes

1

answer

481

views

IMO 2011 Problem 5 - Show that $f(m) \mid f(n)$ if $f(m) \leq f(n)$

number-theory contest-math

jul 21 '11 at 18:40 Luboš Motl 3,715

9

40

votes

5

answers

6

kviews

Convergence of $np(n)$ where $p(n)=\sum_{j=\lceil n/2\rceil}^{n-1} {p(j)\over j}$

sequences-and-series probability stochastic-processes

nov 25 '10 at 23:04 Community♦ 1

9

11

votes

3

answers

620

views

Calculate $\lim_{n \to \infty} \sqrt[n]{|\sin n|}$

homework calculus diophantine-approximation

feb 4 at 10:16 user60927 1

3

14

votes

5

answers

558

views

prove that $\displaystyle\lim_{x\rightarrow 1}\frac{x^{1/m}-1}{x^{1/n}-1}=\frac{n}{m}$

calculus

may 3 '11 at 16:36 Community♦ 1

26

38

votes

5

answers

2

kviews

Strategies for Effective Self-Study

soft-question self-learning

nov 23 at 0:08 Community♦ 1

4

5

votes

4

answers

285

views

prove that $(1 + x)^\frac{1}{b}$ is a formal power series

analysis power-series

may 17 '11 at 18:42 Mark 1,000

6

9

votes

1

answer

294

views

Show that $\gcd(a_{n+1},a_n) > a_{n-1}$ implies $a_n \geq 2^n$

elementary-number-theory

may 15 '11 at 18:38 joriki 92.8k

3

votes

3

answers

2

kviews

Is $\mathbb{Q}(\sqrt{2}) \cong \mathbb{Q}(\sqrt{3})$?

abstract-algebra field-theory

nov 7 '10 at 1:01 Community♦ 1

5

12

votes

1

answer

3

kviews

Is the sum of sin(n)/n convergent or divergent?

sequences-and-series

oct 10 '11 at 11:52 t.b. 43.2k

51

73

votes

5

answers

4

kviews

Intuition for the definition of the Gamma function?

probability-theory intuition gamma-function

jan 23 at 23:19 Victor Wang 141

10

17

votes

1

answer

1

kviews

Proving that the sequence $F_{n}(x)=\sum\limits_{k=1}^{n} \frac{\sin{kx}}{k}$ is boundedly convergent on $\mathbb{R}$

real-analysis analysis sequences-and-series

dec 8 '10 at 6:54 Andrey Rekalo 3,564

8

12

votes

6

answers

2

kviews

How to prove $\cos \frac{2\pi }{5}=\frac{-1+\sqrt{5}}{4}$?

geometry trigonometry euclidean-geometry

sep 26 at 15:54 minthao_2011 560

1

6

votes

2

answers

337

views

Run of $N$ successes before run of $k$ failures

probability

may 1 at 17:42 Byron Schmuland 15.4k

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