User K. Stm. - Mathematics Stack Exchange

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visits	member for	9 months
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	1,749 reputation	bio	website		visits	member for	9 months
213 badges		location			seen	7 hours ago

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5

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Arnold Trivium 49 : $ \oint_{|z|=2}\frac{dz}{\sqrt{1+z^{10}}}$.

6h ago Christian Blatter 34k

16

40

votes

1

answer

582

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Unexpected approximations which have led to important mathematical discoveries

soft-question math-history big-list experimental-mathematics

1d ago Tharsis 1,273

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225

votes

30

answers

32

kviews

My sister absolutely refuses to learn math [closed]

soft-question teaching learning

2d ago daviewales 242

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5

votes

0

answers

83

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Modular interpretation of modular curves

algebraic-number-theory modular-forms

2d ago Zorba le Grec 230

10

16

votes

8

answers

1

kviews

“It looks straightforward, but actually it isn't”

soft-question big-list

jun 16 at 15:22 Joe 83

5

6

votes

2

answers

874

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How to show if $ \lambda$ is an eigenvalue of $AB^{-1}$, then $ \lambda$ is an eigenvalue of $ B^{-1}A$?

linear-algebra matrices functional-analysis

jun 14 at 17:26 robjohn♦ 63.3k

2

4

votes

7

answers

120

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Proving the relation $\det(I + xy^T ) = 1 + x^Ty$

linear-algebra determinant

jun 14 at 14:42 N. S. 30.6k

33

35

votes

5

answers

3

kviews

Lesser-known integration tricks

calculus big-list integration

jun 13 at 5:45 sidht 2,505

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5

votes

4

answers

96

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Tetration limit

limit tetration

jun 4 at 7:41 Gottfried Helms 7,667

167

269

votes

115

answers

14

kviews

What was the first bit of mathematics that made you realize that math is beautiful? (For children's book)

soft-question recreational-mathematics education big-list teaching

jun 2 at 3:15 Sȱɳɨȼ Ʈħe ǶḝÐɠḝħȱɠ 101

2

8

votes

2

answers

177

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Which languages are preferable to study for a mathematician?

soft-question

jun 1 at 9:55 Raskolnikov 7,808

17

32

votes

1

answer

340

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A ring isomorphic to its finite polynomial rings but not to its infinite one.

abstract-algebra commutative-algebra ring-theory

may 30 at 15:11 David Speyer 19.9k

17

25

votes

16

answers

3

kviews

Proof that $\sum\limits_{k=1}^nk^2 = \frac{n(n+1)(2n+1)}{6}$?

sequences-and-series discrete-mathematics proof-strategy

may 28 at 6:43 Abhra Abir Kundu 5,759

56

116

votes

22

answers

9

kviews

Is mathematics one big tautology?

soft-question philosophy

may 27 at 21:40 Mikael Jensen 115

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49

votes

5

answers

5

kviews

Why is 987654321/123456789 = 8.0000000729?

arithmetic rational-numbers

may 22 at 13:12 wkt 1

5

14

votes

1

answer

269

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Why learning modern algebraic geometry is so complicated?

algebraic-geometry soft-question self-learning

may 18 at 17:07 Michael Hardy 51.2k

3

6

votes

2

answers

137

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Need help solving - $ \int (\sin 101x) \cdot\sin^{99}x\,dx $

calculus integral integration indefinite-integral

may 17 at 3:27 Jared 7,570

4

0

votes

1

answer

470

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Philosophy of a Mathematician.

soft-question philosophy foundations

may 14 at 16:34 user18921 4,045

2

8

votes

3

answers

216

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$X\subsetneqq Y$ but $X^\star=Y^\star$

functional-analysis

may 14 at 1:39 julien 25.7k

1

3

votes

1

answer

61

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show that holomorpic function f such that f(1/2n) = f(1/2n+1) are constant

homework complex-analysis

may 13 at 8:19 Bobby Ocean 326

5

17

votes

3

answers

179

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Among all shapes with the same area, a circle has the shortest perimeter

geometry

may 12 at 22:49 newzad 297

2

6

votes

0

answers

60

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Do balls optimize the boundary area for a fixed volume?

geometry differential-geometry optimization

may 12 at 12:06 Feanor 3,301

31

109

votes

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

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2

votes

2

answers

55

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Riemann surface arising as a quotient of the upper half-plane.

complex-analysis riemann-surfaces hyperbolic-geometry covering-spaces

may 11 at 19:16 Landscape 8,842

3

8

votes

1

answer

98

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Regular open set whose boundary has nonzero volume.

general-topology analysis measure-theory fractals

may 11 at 18:24 Martin 4,462

5

10

votes

0

answers

96

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Basic categories cheat sheet

reference-request category-theory

may 11 at 18:08 Fernando Martin 1,669

2

0

votes

2

answers

96

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$GL(n, \mathbb{C})$ is algebraically closed? [closed]

linear-algebra abstract-algebra noncommutative-algebra

may 11 at 16:57 Alexander Gruber♦ 15.8k

1

vote

1

answer

64

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If $f$ is continuous and $g$ is of bounded variation then $f$ is integrable with respect to $g$.

homework real-analysis

may 11 at 16:18 Martin 4,462

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vote

3

answers

60

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Prove that if polynomial's $f(x)=x^6+ax^3+bx^2+cx+d$ , all roots are real, then $a=b=c=d=0$.

linear-algebra

may 11 at 13:18 Inceptio 5,351

7

12

votes

1

answer

129

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Proving the inequality $\tan(1)\le\sum_{k=1}^{\infty} \frac{\sin(1/k^2)}{\cos^2 (1/(k+1))}$

calculus sequences-and-series trigonometry inequality

may 10 at 22:15 O.L. 7,248

K. Stm.

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