User espacodual

6 votes

$A$ is a countable set if and only if exist a injective function $h: A \to \mathbb{N} $

answered Sep 30, 2017 at 5:47

4 votes

Accepted

Show that operator $S$ is invertible

answered Oct 9, 2017 at 5:16

3 votes

Prove that $x^5 + 4x^4 + 2x^3 + x^2 + 4x + 54$ is irreducible over $\mathbb{Z} / 7\mathbb{Z}$

answered Dec 2, 2017 at 22:55

3 votes

Is the function $g:\mathbb{Z} \times\mathbb{Z} \rightarrow \mathbb{Z} $ given by $g(m,n)=14m+21n$ onto?

answered Sep 30, 2017 at 20:44

3 votes

Accepted

Find the Galois group of $x^3-2x-1$ over $\mathbb{Q}$ and over $\mathbb{Q}(\sqrt{5})$

answered Oct 3, 2017 at 0:10

3 votes

Construction of any projective representation of SU(2)

answered Sep 27, 2017 at 14:57

2 votes

Accepted

Function defined over all a set (NOTATION)

answered Dec 3, 2017 at 1:36

2 votes

Is it really necessary to choose a basis to prove that every element of a comodule is contained in a finite-dimensional subcomodule?

answered Oct 11, 2022 at 12:47

1 vote

How to simplify an ideal (f,g) division with remainder

answered Sep 27, 2017 at 14:35

1 vote

Accepted

Lie algebra of an algebraic group

answered Oct 6, 2022 at 17:32

1 vote

Monoidal category with initial object

answered Feb 8, 2023 at 15:06

1 vote

Moving Integral Inside A Product

answered Sep 29, 2017 at 12:31

1 vote

Is real line a closed or open interval?

answered Sep 30, 2017 at 4:45

0 votes

How to interpret the action of a projective linear group on a projective space?

answered Oct 5, 2017 at 1:19

0 votes

Finding cyclic subgroups of a non-cyclic group

answered Oct 8, 2017 at 1:28

0 votes

Finding the equation of a tangent plane given an implicity defined function and obtaining $8$ roots

answered Oct 9, 2017 at 4:39

0 votes

What does $x^n=y^n$ imply for $x=\pm y$ in a group?

answered Nov 26, 2017 at 3:12

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17 Answers

$A$ is a countable set if and only if exist a injective function $h: A \to \mathbb{N} $

Show that operator $S$ is invertible

Prove that $x^5 + 4x^4 + 2x^3 + x^2 + 4x + 54$ is irreducible over $\mathbb{Z} / 7\mathbb{Z}$

Is the function $g:\mathbb{Z} \times\mathbb{Z} \rightarrow \mathbb{Z} $ given by $g(m,n)=14m+21n$ onto?

Find the Galois group of $x^3-2x-1$ over $\mathbb{Q}$ and over $\mathbb{Q}(\sqrt{5})$

Construction of any projective representation of SU(2)

Function defined over all a set (NOTATION)

Is it really necessary to choose a basis to prove that every element of a comodule is contained in a finite-dimensional subcomodule?

How to simplify an ideal (f,g) division with remainder

Lie algebra of an algebraic group

Monoidal category with initial object

Moving Integral Inside A Product

Is real line a closed or open interval?

How to interpret the action of a projective linear group on a projective space?

Finding cyclic subgroups of a non-cyclic group

Finding the equation of a tangent plane given an implicity defined function and obtaining $8$ roots

What does $x^n=y^n$ imply for $x=\pm y$ in a group?