User user10354138

30 votes

"Naturally occurring" non-Hausdorff spaces?

answered Aug 3, 2020 at 1:35

20 votes

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Find the limit $\lim _{n \to \infty}(n!)^{{\frac{1}{n^2}}}$

answered Jun 8, 2019 at 9:14

19 votes

Proving this inequality without calculus

answered Sep 23, 2018 at 17:12

13 votes

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value of $\int_{-\infty}^{\infty}\arcsin\frac1{\cosh x}\,dx$

answered Oct 31, 2018 at 3:22

13 votes

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Understanding the distance between a line and a point in 3D space

answered Nov 1, 2018 at 0:10

11 votes

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The map from SU(4) to SO(6)

answered Nov 5, 2018 at 10:50

10 votes

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Does there exist a non-trivial group that is both perfect and complete?

answered Jun 16, 2019 at 14:09

10 votes

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Well ordering principle for rationals

answered Sep 21, 2018 at 7:28

10 votes

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Let $G$ be a finite group. If $a = bab$, is it true that $b^{2} = e$

answered Nov 1, 2018 at 4:10

9 votes

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Infinite dimensional vector space

answered Jun 17, 2019 at 12:57

9 votes

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Calibrations vs. Riemannian holonomy

answered Jun 18, 2019 at 21:44

9 votes

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Strongest topology that makes vector space locally convex

answered Jun 20, 2019 at 12:55

9 votes

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What is the intuition behind pushouts and pullbacks in category theory?

answered Aug 4, 2020 at 13:20

9 votes

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$\sigma$-algebra generated by open balls

answered Aug 8, 2020 at 10:50

9 votes

Fubini's theorem and reparameterisation

answered 2 days ago

9 votes

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Evaluating $\int_0^\infty\operatorname{erfi}(x)e^{-x^2}\frac{dx}x$

answered Sep 13, 2018 at 4:50

8 votes

If $\lim_{\alpha \to \infty}\alpha P[X > \alpha] = 0$ then $E[X] < \infty$?

answered Aug 7, 2020 at 18:16

8 votes

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Is the set of continuous maps on $[0,1]$ with finitely many roots open in the $C^0$ topology?

answered Sep 15 at 21:19

8 votes

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Wish to evaluate $\int_{0}^{1}\frac{x^4-3x^2+2x}{\sin(\pi x)} dx$

answered Jun 13, 2019 at 9:48

8 votes

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What does $\text{Sp}(n)\cdot\text{Sp}(1)$ mean in Berger's holonomy list?

answered Jun 13, 2019 at 17:35

7 votes

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For an ideal $I$, why might not $I$=$I^2$?

answered Jun 26, 2019 at 15:15

7 votes

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Does $G/H\cong \mathbb{Z}^n$ with $H\cong \mathbb{Z}^m$ imply that $G\cong \mathbb{Z}^{m+n}$?

answered Feb 6, 2021 at 14:08

7 votes

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need help solving a quartic equation

answered Jul 21, 2020 at 14:46

7 votes

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$f$ continuous with derivative $f'(x)=0$ for all $x\in \mathbb{R}\setminus A$ where $A$ is countable implies $f$ constant

answered Sep 25, 2021 at 6:43

7 votes

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Fundamental group of the real projective plane and its universal cover

answered Jun 7, 2019 at 15:35

7 votes

Find the value of $a_4-a_2$

answered Jun 7, 2019 at 5:38

7 votes

How to show that $\langle a,b \mid aba^{-1}ba = bab^{-1}ab\rangle$ is not Abelian?

answered Nov 24, 2018 at 2:44

7 votes

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Example of no non-constant meromorphic functions

answered May 3, 2019 at 11:05

7 votes

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If $f(b)-f(a)=(b-a)f'(\frac{a+b}{2})$ prove that any such function is a polynomial of degree $2$

answered May 12, 2019 at 3:17

7 votes

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Dual of an elliptic curve?

answered May 13, 2019 at 6:03

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1,246 Answers

"Naturally occurring" non-Hausdorff spaces?

Find the limit $\lim _{n \to \infty}(n!)^{{\frac{1}{n^2}}}$

Proving this inequality without calculus

value of $\int_{-\infty}^{\infty}\arcsin\frac1{\cosh x}\,dx$

Understanding the distance between a line and a point in 3D space

The map from SU(4) to SO(6)

Does there exist a non-trivial group that is both perfect and complete?

Well ordering principle for rationals

Let $G$ be a finite group. If $a = bab$, is it true that $b^{2} = e$

Infinite dimensional vector space

Calibrations vs. Riemannian holonomy

Strongest topology that makes vector space locally convex

What is the intuition behind pushouts and pullbacks in category theory?

$\sigma$-algebra generated by open balls

Fubini's theorem and reparameterisation

Evaluating $\int_0^\infty\operatorname{erfi}(x)e^{-x^2}\frac{dx}x$

If $\lim_{\alpha \to \infty}\alpha P[X > \alpha] = 0$ then $E[X] < \infty$?

Is the set of continuous maps on $[0,1]$ with finitely many roots open in the $C^0$ topology?

Wish to evaluate $\int_{0}^{1}\frac{x^4-3x^2+2x}{\sin(\pi x)} dx$

What does $\text{Sp}(n)\cdot\text{Sp}(1)$ mean in Berger's holonomy list?

For an ideal $I$, why might not $I$=$I^2$?

Does $G/H\cong \mathbb{Z}^n$ with $H\cong \mathbb{Z}^m$ imply that $G\cong \mathbb{Z}^{m+n}$?

need help solving a quartic equation

$f$ continuous with derivative $f'(x)=0$ for all $x\in \mathbb{R}\setminus A$ where $A$ is countable implies $f$ constant

Fundamental group of the real projective plane and its universal cover

Find the value of $a_4-a_2$

How to show that $\langle a,b \mid aba^{-1}ba = bab^{-1}ab\rangle$ is not Abelian?

Example of no non-constant meromorphic functions

If $f(b)-f(a)=(b-a)f'(\frac{a+b}{2})$ prove that any such function is a polynomial of degree $2$

Dual of an elliptic curve?