User Isomorphism - Mathematics Stack Exchange

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visits	member for	1 year, 8 months
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	1,494 reputation	bio	website		visits	member for	1 year, 8 months
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91

131

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Different methods to compute $\sum\limits_{n=1}^\infty \frac{1}{n^2}$

mar 8 at 13:57 xpaul 1

31

105

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3

answers

5

kviews

The Integral that Stumped Feynman?

real-analysis complex-analysis reference-request integral contour-integration

may 12 at 1:10 Joel 130

19

71

votes

3

answers

6

kviews

Why can a Venn diagram for 4+ sets not be constructed using circles?

geometry combinatorics logic

feb 23 at 21:52 vonbrand 6,616

27

46

votes

17

answers

2

kviews

What are some good ways to get children excited about math?

big-list teaching

mar 12 at 18:22 Arkamis 7,977

33

42

votes

8

answers

2

kviews

Intuition in algebra?

abstract-algebra soft-question intuition

may 13 '12 at 1:21 AbstractionOfMe 184

17

40

votes

3

answers

896

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Paul Erdos's Two-Line Functional Analysis Proof

functional-analysis reference-request math-history

feb 15 at 4:12 zyx 11.1k

19

39

votes

19

answers

2

kviews

What is your favorite application of the Pigeonhole Principle?

big-list teaching pigeonhole-principle

oct 5 at 14:27 David Speyer 18.7k

10

28

votes

6

answers

1

kviews

Attitude towards exercises in mathematics

soft-question self-learning

nov 4 '11 at 4:40 Alvin K. 121

7

23

votes

3

answers

838

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Random Variable Inequality

probability-theory measure-theory inequality probability

dec 28 '10 at 8:04 Roah 512

6

23

votes

2

answers

938

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Are there infinitely many $x$ for which $\pi(x) \mid x$?

number-theory analytic-number-theory

sep 20 '11 at 4:54 Charles 8,860

6

22

votes

2

answers

673

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Drunkard's walk on the $n^{th}$ roots of unity.

probability stochastic-processes markov-chains roots-of-unity

jul 20 at 22:52 J. M. 38.9k

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21

votes

11

answers

2

kviews

Fun Linear Algebra Problems

linear-algebra big-list

jun 11 '11 at 7:41 Joel Cohen 3,669

7

19

votes

3

answers

494

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Why everytime the final number comes the same?

algebra-precalculus puzzle

mar 31 '12 at 4:22 Bidit Acharya 1,285

5

17

votes

1

answer

149

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To prove that $2^{3n}+2^n +1$ is not a perfect square.

algebra-precalculus elementary-number-theory contest-math

may 15 at 4:49 Inceptio 4,835

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16

votes

3

answers

200

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How to prove summation, multiplication, subtraction of two roots of $1+x+\frac{x^2}{2!}+\cdots+\frac{x^p}{p!}=0$ aren't rationals?

homework polynomials algebraic-number-theory galois-theory

mar 2 at 10:13 YACP 9,210

5

12

votes

3

answers

313

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$\sum\limits_{\text{prime }p} 2^{-p}$ is an irrational number

homework sequences-and-series number-theory prime-numbers

may 20 at 5:43 marty cohen 6,892

5

12

votes

1

answer

325

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When does the modular law apply to ideals in a commutative ring

abstract-algebra commutative-algebra

mar 27 at 16:46 azimut 5,508

2

11

votes

1

answer

167

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How can prove this equation.

trigonometry functional-equations

mar 13 at 15:36 Ivan Loh 7,603

8

11

votes

2

answers

1

kviews

Automorphism of the Field of rational functions

homework abstract-algebra

nov 23 '11 at 19:19 Arturo Magidin 158k

6

10

votes

2

answers

205

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$x^2+x+1$ is the cube of a prime.

number-theory prime-numbers

may 17 at 12:42 CODE 553

4

9

votes

1

answer

455

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Do these matrix rings have non-zero elements that are neither units nor zero divisors?

linear-algebra abstract-algebra matrices ring-theory

oct 11 '11 at 16:12 joriki 92.8k

3

8

votes

3

answers

381

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Examples of rings with ideal lattice isomorphic to $M_3$, $N_5$

commutative-algebra ring-theory order-theory ideals lattice-orders

jun 6 '12 at 21:13 rschwieb 21.1k

2

6

votes

1

answer

164

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coloring a $4\times 4$ square with $4$ colors

combinatorics

feb 24 '12 at 2:35 jp26 553

8

5

votes

4

answers

558

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Favorite Math Competition Problems

contest-math

jun 16 '11 at 0:57 ncmathsadist 17.2k

2

4

votes

0

answers

109

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Is there a Mazur–Ulam theorem equivalent for vector spaces over finite fields?

linear-algebra abstract-algebra coding-theory

nov 9 '11 at 12:18 Jyrki Lahtonen 30.9k

1

4

votes

0

answers

47

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Evaluate $\int_0^{\infty} \frac{1-e^{-ax}}{x e^x} dx$

real-analysis multivariable-calculus

may 18 at 9:34 A.D 1,557

2

3

votes

2

answers

32

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sum of polynoms of given property

polynomials derivatives

may 21 at 9:17 Seirios 8,942

1

2

votes

2

answers

37

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Confused about combinatorials

homework

may 15 at 2:46 user17762 76.6k

1

2

votes

2

answers

359

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Linearity of convergence in distribution of random variables

probability-theory

nov 9 '10 at 18:40 Shai Covo 17k

Isomorphism

29 Favorites