User CutieKrait - Mathematics Stack Exchange

bio	website	above_destruction.
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	1,712 reputation	bio	website	above_destruction.	visits	member for	3 months
2330 badges		location	(x,y,z) in some Cartisian space is my mass center.		seen	13 mins ago

149

377

votes

25

answers

24

kviews

Can I use my powers for good?

soft-question career-development

apr 11 at 0:40 MGA 75

166

266

votes

115

answers

13

kviews

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

may 6 at 4:59 Jori Mäntysalo 31

182

162

votes

23

answers

10

kviews

Proofs that every mathematician should know?

soft-question big-list

mar 25 at 0:36 Glen O 3,177

70

161

votes

13

answers

12

kviews

Is value of $\pi = 4$?

geometry analysis pi fake-proofs

1d ago robjohn♦ 59.6k

67

85

votes

40

answers

4

kviews

Funny identities

big-list

apr 29 at 6:07 John Marty 983

41

60

votes

6

answers

3

kviews

Prove elementarily that $\sqrt[n+1] {(n+1)!} - \sqrt[n] {n!}$ is strictly decreasing

sequences-and-series

apr 3 at 3:36 Mark Hurd 372

39

56

votes

8

answers

2

kviews

Self-Contained Proof that $\sum\limits_{n=1}^{\infty} \frac1{n^p}$ Converges for $p > 1$

calculus real-analysis sequences-and-series

sep 24 at 6:50 chatur 117

10

54

votes

2

answers

2

kviews

Does this property characterize a space as Hausdorff?

general-topology

nov 14 '10 at 21:08 Arturo Magidin 158k

16

48

votes

5

answers

3

kviews

Is there an elementary proof that $\sum \limits_{k=1}^n \frac1k$ is never an integer?

number-theory sequences-and-series

nov 27 at 16:40 B.Sahu 1

23

32

votes

7

answers

4

kviews

Advantages of IMO students in Mathematical Research

soft-question

jan 30 at 5:39 Community♦ 1

18

31

votes

5

answers

799

views

Studying for the Putnam Exam

big-list contest-math self-learning learning

apr 4 at 7:50 zyx 11k

5

23

votes

3

answers

806

views

If every continuous $f:X\to X$ has $\text{Fix}(f)\subseteq X$ closed, must $X$ be Hausdorff?

general-topology examples-counterexamples

jan 31 '12 at 0:22 Srivatsan 15.6k

6

20

votes

1

answer

214

views

When is Stone-Čech compactification the same as one-point compactification?

general-topology compactness

mar 27 at 5:32 Martin Sleziak 20.3k

10

19

votes

1

answer

434

views

Recovering a finite group's structure from the order of its elements.

abstract-algebra group-theory finite-groups abelian-groups computational-algebra

nov 4 at 16:53 Alexander Gruber♦ 15.2k

8

17

votes

2

answers

199

views

Are these exactly the abelian groups?

group-theory abelian-groups

feb 15 at 6:16 Hurkyl 21.5k

7

17

votes

2

answers

700

views

Does $\sin(x)=y$ have a solution in $\mathbb{Q}$ beside $x=y=0$

number-theory irrational-numbers transcendental-numbers

mar 30 at 20:48 Dominic Michaelis 11.9k

5

15

votes

5

answers

569

views

Can two topological spaces surject onto each other but not be homeomorphic?

general-topology examples-counterexamples

jul 19 at 7:26 Community♦ 1

6

14

votes

1

answer

303

views

What are all conditions on a finite sequence $x_1,x_2,…,x_m$ such that it is the sequence of orders of elements of a group?

abstract-algebra group-theory graph-theory finite-groups

apr 15 at 23:37 Alexander Gruber♦ 15.2k

1

13

votes

0

answers

202

views

Continuity of a function to the integers

general-topology

apr 2 at 20:39 user69810 831

2

11

votes

4

answers

371

views

Short forms like “haven't”, “don't”, “let's”

soft-question terminology article-writing

dec 10 at 19:34 Peter Smith 11.6k

4

11

votes

3

answers

218

views

Order of the smallest group containing all groups of order $n$ as subgroups.

abstract-algebra group-theory finite-groups asymptotics

apr 15 at 21:08 Alexander Gruber♦ 15.2k

4

11

votes

1

answer

493

views

Show that $f(x+y)=f(x)+f(y)$ implies $f$ continuous $\Leftrightarrow$ $f$ measurable

real-analysis

nov 7 '11 at 3:17 t.b. 43.2k

2

11

votes

1

answer

206

views

Show that there are no functions $f: \mathbb R \to \mathbb R$ which have the intermediate value property and $f(f(x))=\cos^2(x)$

calculus

apr 6 at 12:44 suissidle 415

5

10

votes

1

answer

107

views

Convergence of this series

calculus sequences-and-series

apr 9 at 9:24 Ju'x 2,934

1

10

votes

2

answers

115

views

how prove $n! \mid \prod_{k=0}^{n-1}(2^n-2^k) :\forall n \in \mathbb N$?

number-theory contest-math

mar 19 at 23:12 anon 39.9k

3

10

votes

0

answers

187

views

An estimate for relatively prime numbers

number-theory prime-numbers

jan 2 '12 at 8:25 Vladimir 51

2

10

votes

2

answers

735

views

Limit of $(\sin\circ\sin\circ\cdots\circ\sin)(x)$

calculus

aug 23 '11 at 9:50 Did 103k

4

9

votes

5

answers

883

views

A compact Hausdorff space that is not metrizable

general-topology examples-counterexamples compactness

jun 13 '12 at 5:59 Asaf Karagila 91k

5

9

votes

1

answer

130

views

Definition of amenable group

group-theory amenability

feb 25 at 5:11 Martin 3,688

3

9

votes

1

answer

141

views

Are $(\mathbb{R},+)$ and $(\mathbb{C},+)$ isomorphic as additive groups?

group-theory abelian-groups

feb 13 at 22:55 Asaf Karagila 91k

CutieKrait

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