User GEdgar

180 votes

Prove that every convex function is continuous

answered Dec 21, 2013 at 21:51

101 votes

In classical logic, why is $(p\Rightarrow q)$ True if both $p$ and $q$ are False?

answered Jun 28, 2011 at 12:32

88 votes

To sum $1+2+3+\cdots$ to $-\frac1{12}$

answered May 18, 2011 at 12:58

86 votes

Is this Batman equation for real?

answered Jul 29, 2011 at 21:59

64 votes

Accepted

Cauchy Sequence that Does Not Converge

answered Mar 12, 2012 at 15:55

62 votes

Formula for the simple sequence 1, 2, 2, 3, 3, 4, 4, 5, 5, ...

answered Jan 31, 2016 at 1:28

61 votes

Do men or women have more brothers?

answered May 21, 2016 at 19:09

59 votes

Is there a chain rule for integration?

answered Feb 1, 2016 at 14:44

58 votes

Accepted

Is there a function with the property $f(n)=f^{(n)}(0)$?

answered Dec 16, 2011 at 4:03

58 votes

Accepted

Is there any function which grows 'slower' than its derivative?

answered Feb 2, 2015 at 22:26

52 votes

Is it irrational?

answered Feb 19, 2016 at 13:39

48 votes

Example of filtration in probability theory

answered Nov 7, 2017 at 19:46

44 votes

Accepted

Is there a sign for 'not less than', 'not greater than', etc.?

answered May 19, 2016 at 14:15

38 votes

Accepted

Is there a differentiable function such that $f(\mathbb Q) \subseteq \mathbb Q$ but $f'(\mathbb Q) \not \subseteq \mathbb Q$?

answered Aug 12, 2020 at 12:47

38 votes

Real life applications of Topology

answered Oct 18, 2011 at 18:03

34 votes

Why is $\wedge$ a minimum and $\vee$ a maximum?

answered Jun 25, 2016 at 16:17

33 votes

Accepted

LOVE +MATH = can you read this formula?

answered Oct 18, 2011 at 14:33

33 votes

Example of a group where $o(a)$ and $o(b)$ are finite but $o(ab)$ is infinite

answered Feb 26, 2013 at 14:17

32 votes

Accepted

Computing $ \sum\limits_{i=1}^{\infty}\sum\limits_{j=1}^{\infty} \frac{(-1)^{i+j}}{i+j}$

answered Apr 11, 2012 at 21:36

29 votes

Accepted

Is there any matrix $2\times 2$ such that $A\neq I$ but $ A^3=I$?

answered Aug 20, 2011 at 15:06

28 votes

Accepted

Is the algebraic closure of a $p$-adic field complete

answered Mar 24, 2012 at 13:38

28 votes

What are the ways of proving that the Cantor set is uncountable apart from Cantor diagonalization?

answered Dec 4, 2012 at 15:57

28 votes

Why is the exponential function not in the subspace of all polynomials?

answered Oct 6, 2016 at 12:21

27 votes

Bounded harmonic function is constant

answered Jan 28, 2012 at 14:16

25 votes

Why do we need to learn integration techniques?

answered Aug 31, 2012 at 0:24

24 votes

Is there more than one way to divide the "L"-shaped tromino into four congruent, connected pieces?

answered Sep 17, 2015 at 13:14

24 votes

Is there a way to write an infinite set that contains only irrational numbers without integer multiples?

answered Apr 24, 2016 at 13:19

23 votes

Finding a paper

answered May 23, 2011 at 1:42

23 votes

A complete orthonormal system contained in a dense sub-space.

answered Sep 23, 2012 at 13:47

22 votes

Is $\exp(x)$ the same as $e^x$?

answered Apr 8, 2015 at 21:44

Stack Exchange Network

3,072 Answers

Prove that every convex function is continuous

In classical logic, why is $(p\Rightarrow q)$ True if both $p$ and $q$ are False?

To sum $1+2+3+\cdots$ to $-\frac1{12}$

Is this Batman equation for real?

Cauchy Sequence that Does Not Converge

Formula for the simple sequence 1, 2, 2, 3, 3, 4, 4, 5, 5, ...

Do men or women have more brothers?

Is there a chain rule for integration?

Is there a function with the property $f(n)=f^{(n)}(0)$?

Is there any function which grows 'slower' than its derivative?

Is it irrational?

Example of filtration in probability theory

Is there a sign for 'not less than', 'not greater than', etc.?

Is there a differentiable function such that $f(\mathbb Q) \subseteq \mathbb Q$ but $f'(\mathbb Q) \not \subseteq \mathbb Q$?

Real life applications of Topology

Why is $\wedge$ a minimum and $\vee$ a maximum?

LOVE +MATH = can you read this formula?

Example of a group where $o(a)$ and $o(b)$ are finite but $o(ab)$ is infinite

Computing $ \sum\limits_{i=1}^{\infty}\sum\limits_{j=1}^{\infty} \frac{(-1)^{i+j}}{i+j}$

Is there any matrix $2\times 2$ such that $A\neq I$ but $ A^3=I$?

Is the algebraic closure of a $p$-adic field complete

What are the ways of proving that the Cantor set is uncountable apart from Cantor diagonalization?

Why is the exponential function not in the subspace of all polynomials?

Bounded harmonic function is constant

Why do we need to learn integration techniques?

Is there more than one way to divide the "L"-shaped tromino into four congruent, connected pieces?

Is there a way to write an infinite set that contains only irrational numbers without integer multiples?

Finding a paper

A complete orthonormal system contained in a dense sub-space.

Is $\exp(x)$ the same as $e^x$?