User user156441

17 votes

3 answers

9k views

Graph of real continuous function has measure zero

asked Mar 28, 2015 at 5:22

15 votes

2 answers

5k views

$p$ prime, Group of order $p^n$ is cyclic iff it is an abelian group having a unique subgroup of order $p$

asked Sep 27, 2014 at 22:11

12 votes

1 answer

6k views

Equivalent norms understanding proof visually

asked Jul 31, 2016 at 19:46

11 votes

2 answers

2k views

group of module homomorphisms is a module

asked Oct 3, 2014 at 19:55

10 votes

4 answers

1k views

$\mathbb Z[i]/ \langle 1+2i \rangle \cong \mathbb Z_5$

asked Jun 10, 2015 at 19:21

9 votes

3 answers

352 views

$\mathbb Z^n/\langle (a,...,a) \rangle \cong \mathbb Z^{n-1} \oplus \mathbb Z/\langle a \rangle$

asked Dec 1, 2014 at 20:15

9 votes

1 answer

6k views

Prove that $\cos(z)$ and $\sin(z)$ are surjective over the complex numbers. [duplicate]

asked Jun 19, 2014 at 3:47

6 votes

1 answer

3k views

Cross ratio and symmetric points exercise

asked Jun 23, 2014 at 23:45

6 votes

2 answers

4k views

Connected topological spaces, product is connected

asked Aug 27, 2014 at 15:23

5 votes

1 answer

780 views

If $0 \to M \to N \to S \to 0$ splits, then $N \cong M \oplus N$

asked Oct 15, 2014 at 22:23

5 votes

0 answers

132 views

Proving a holomorphic function is constant on an open connected set under certain conditions. [duplicate]

asked Jun 30, 2014 at 19:37

5 votes

1 answer

2k views

$2\times 2$ matrix $C=AB-BA$

asked Jan 3, 2015 at 21:08

5 votes

1 answer

510 views

$SL_2(\mathbb Z_3)/Z(SL_2(\mathbb Z_3)) \cong A_4$

asked Jun 14, 2015 at 19:12

5 votes

2 answers

3k views

Eigenvalues of composition of functions

asked May 25, 2015 at 18:30

5 votes

2 answers

479 views

Lebesgue-measurable function problem

asked Sep 28, 2015 at 22:13

5 votes

2 answers

2k views

Zariski topology, non-empty intersection of open sets

asked Mar 18, 2016 at 3:10

5 votes

1 answer

2k views

Graph $G$ with different weights on edges has unique minimum spanning tree

asked Jul 7, 2018 at 18:34

4 votes

1 answer

500 views

Radius of convergence of two power series

asked May 6, 2016 at 6:42

4 votes

2 answers

511 views

For a semisimple ring, if $M \oplus P \cong N \oplus P$, then $M \cong N$ (finitely generated $M$, $N$, $P$)

asked Dec 8, 2014 at 8:10

4 votes

1 answer

839 views

Inner measure of Vitali Set

asked Mar 29, 2015 at 6:32

4 votes

3 answers

417 views

Group of order $135$ abelian and not cyclic

asked May 7, 2015 at 14:29

4 votes

2 answers

4k views

$M$ is a simple module if and only if $M \cong R/I$ for some $I$ maximal ideal in $R$.

asked Oct 12, 2014 at 0:13

4 votes

1 answer

478 views

Characterize semisimple rings of quotients

asked Nov 11, 2014 at 4:56

4 votes

1 answer

159 views

$G/Z(G) \cong \mathbb Z_p \times \mathbb Z_p$ then $p||Z(G)|$

asked Nov 27, 2014 at 8:11

3 votes

2 answers

2k views

Vector space as simple $K[x]$-module

asked Oct 12, 2014 at 17:02

3 votes

2 answers

4k views

Finding equilibrium points of differential equation

asked Sep 3, 2014 at 6:05

3 votes

1 answer

1k views

Semidirect products of $\mathbb Z_3$ and $\mathbb Z_4$

asked Sep 24, 2014 at 4:06

3 votes

2 answers

1k views

Proof of Gauss theorem (divergence theorem) in $\mathbb R^2$

asked Sep 12, 2014 at 17:19

3 votes

1 answer

694 views

If $f$,$g$ and $\overline{f}g$ are holomorphic on $\Omega$, then $g=0$ or $f$ is constant

asked Jul 4, 2014 at 19:04

3 votes

1 answer

322 views

Finding Möbius transformations that satistfy certain conditions

asked Jun 26, 2014 at 12:27

Stack Exchange Network

190 Questions

Graph of real continuous function has measure zero

$p$ prime, Group of order $p^n$ is cyclic iff it is an abelian group having a unique subgroup of order $p$

Equivalent norms understanding proof visually

group of module homomorphisms is a module

$\mathbb Z[i]/ \langle 1+2i \rangle \cong \mathbb Z_5$

$\mathbb Z^n/\langle (a,...,a) \rangle \cong \mathbb Z^{n-1} \oplus \mathbb Z/\langle a \rangle$

Prove that $\cos(z)$ and $\sin(z)$ are surjective over the complex numbers. [duplicate]

Cross ratio and symmetric points exercise

Connected topological spaces, product is connected

If $0 \to M \to N \to S \to 0$ splits, then $N \cong M \oplus N$

Proving a holomorphic function is constant on an open connected set under certain conditions. [duplicate]

$2\times 2$ matrix $C=AB-BA$

$SL_2(\mathbb Z_3)/Z(SL_2(\mathbb Z_3)) \cong A_4$

Eigenvalues of composition of functions

Lebesgue-measurable function problem

Zariski topology, non-empty intersection of open sets

Graph $G$ with different weights on edges has unique minimum spanning tree

Radius of convergence of two power series

For a semisimple ring, if $M \oplus P \cong N \oplus P$, then $M \cong N$ (finitely generated $M$, $N$, $P$)

Inner measure of Vitali Set

Group of order $135$ abelian and not cyclic

$M$ is a simple module if and only if $M \cong R/I$ for some $I$ maximal ideal in $R$.

Characterize semisimple rings of quotients

$G/Z(G) \cong \mathbb Z_p \times \mathbb Z_p$ then $p||Z(G)|$

Vector space as simple $K[x]$-module

Finding equilibrium points of differential equation

Semidirect products of $\mathbb Z_3$ and $\mathbb Z_4$

Proof of Gauss theorem (divergence theorem) in $\mathbb R^2$

If $f$,$g$ and $\overline{f}g$ are holomorphic on $\Omega$, then $g=0$ or $f$ is constant

Finding Möbius transformations that satistfy certain conditions