User Conifold

18 votes

1 answer

731 views

Are there spaces that 'look the same' at every point, but are not homogeneous?

asked May 28, 2015 at 1:30

18 votes

2 answers

1k views

Are there non-standard counterexamples to the Fermat Last Theorem?

asked Jul 28, 2016 at 2:57

14 votes

2 answers

1k views

Why do we know that Gödel sentences are true in the standard model of set theory, but do not know if the continuum hypothesis is?

asked Jun 30, 2015 at 21:36

13 votes

2 answers

508 views

Is Archimedes's method for computing volumes equivalent to Cavalieri's?

asked Jan 12, 2015 at 22:11

12 votes

1 answer

2k views

What is the reflection across a parabola?

asked May 22, 2015 at 22:27

11 votes

1 answer

256 views

Is there a clever way to find a smaller number that produces the Euclidean algorithm of given length?

asked May 5, 2016 at 20:11

10 votes

3 answers

63k views

Are triangles the strongest shape?

asked Aug 12, 2015 at 4:23

9 votes

2 answers

531 views

How many different products can be formed by multiplying $n$ numbers at most once?

asked Jun 27, 2017 at 23:27

8 votes

1 answer

952 views

Why is the powerset axiom more acceptable than the axiom of choice?

asked Aug 20, 2014 at 22:17

7 votes

1 answer

700 views

Partial order on cardinalities without the axiom of choice

asked Jun 17, 2014 at 21:49

7 votes

1 answer

4k views

Functions with every point being a Lebesgue point

asked Jul 7, 2014 at 22:19

7 votes

2 answers

2k views

What is the multiplicative order of a product of two integers $\mod n$?

asked Aug 29, 2018 at 21:46

6 votes

1 answer

809 views

Circle inversion and the Pappus chain paradox

asked Jan 25, 2018 at 22:48

6 votes

1 answer

452 views

Is there a theory of integration in elementary terms for definite integrals?

asked Aug 18, 2014 at 20:18

6 votes

1 answer

464 views

How do inconsistent arithmetics get around Gödel incompleteness?

asked Nov 11, 2015 at 20:36

6 votes

1 answer

606 views

Are all rationally parametrized plane curves algebraic? How does one find their degree?

asked Jan 15, 2016 at 0:48

5 votes

2 answers

448 views

Can one prove existence of incommensurables without the Pythagorean theorem?

asked Aug 28, 2014 at 19:10

5 votes

1 answer

599 views

Finding covering system of congruences with prescribed moduli

asked May 21, 2014 at 23:53

4 votes

0 answers

160 views

Can existence of aleph one be proved without the power set axiom? [duplicate]

asked May 24, 2014 at 22:08

4 votes

1 answer

764 views

Can hyperreal numbers be studied 'naively', like surreal numbers?

asked May 29, 2014 at 0:55

4 votes

1 answer

2k views

What is the dual space in the strong operator topology?

asked May 29, 2014 at 21:54

4 votes

1 answer

112 views

How many integer matrices have spectral radius bounded by a constant?

asked Jul 23, 2021 at 3:36

4 votes

2 answers

150 views

Example of a sequence that is Cauchy in a stronger norm and convergent in a weaker norm, but not convergent in the stronger norm?

asked Aug 16 at 0:45

3 votes

1 answer

344 views

Banach valued sequence spaces $\ell^p(X)$

asked Jul 20, 2014 at 1:24

3 votes

0 answers

100 views

Is there an intuitive reason why hippopede, the intersection curve of a sphere and a cylinder, is traced by composing two rotational motions?

asked Jan 15, 2015 at 18:22

2 votes

1 answer

462 views

Are order isomorphic real closed fields isomorphic?

asked Aug 7, 2014 at 19:55

0 votes

1 answer

126 views

Is there a formalisation of set theory where unions can be taken over some classes that are not a priori known to be sets?

asked May 25, 2014 at 3:49

0 votes

1 answer

324 views

Non-convex functions and their supporting hyperplanes

asked Mar 8, 2020 at 1:26

Stack Exchange Network

28 Questions

Are there spaces that 'look the same' at every point, but are not homogeneous?

Are there non-standard counterexamples to the Fermat Last Theorem?

Why do we know that Gödel sentences are true in the standard model of set theory, but do not know if the continuum hypothesis is?

Is Archimedes's method for computing volumes equivalent to Cavalieri's?

What is the reflection across a parabola?

Is there a clever way to find a smaller number that produces the Euclidean algorithm of given length?

Are triangles the strongest shape?

How many different products can be formed by multiplying $n$ numbers at most once?

Why is the powerset axiom more acceptable than the axiom of choice?

Partial order on cardinalities without the axiom of choice

Functions with every point being a Lebesgue point

What is the multiplicative order of a product of two integers $\mod n$?

Circle inversion and the Pappus chain paradox

Is there a theory of integration in elementary terms for definite integrals?

How do inconsistent arithmetics get around Gödel incompleteness?

Are all rationally parametrized plane curves algebraic? How does one find their degree?

Can one prove existence of incommensurables without the Pythagorean theorem?

Finding covering system of congruences with prescribed moduli

Can existence of aleph one be proved without the power set axiom? [duplicate]

Can hyperreal numbers be studied 'naively', like surreal numbers?

What is the dual space in the strong operator topology?

How many integer matrices have spectral radius bounded by a constant?

Example of a sequence that is Cauchy in a stronger norm and convergent in a weaker norm, but not convergent in the stronger norm?

Banach valued sequence spaces $\ell^p(X)$

Is there an intuitive reason why hippopede, the intersection curve of a sphere and a cylinder, is traced by composing two rotational motions?

Are order isomorphic real closed fields isomorphic?

Is there a formalisation of set theory where unions can be taken over some classes that are not a priori known to be sets?

Non-convex functions and their supporting hyperplanes