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excalibirr
  • Member for 8 years, 5 months
  • Last seen more than 4 years ago
  • Europe
7 votes
3 answers
11k views

Understanding the difference between pre-image and inverse

6 votes
4 answers
2k views

Minimum polynomial of a root involving the 7th root of unity

4 votes
1 answer
153 views

Are the following subsets open wrt the metric topology?

4 votes
1 answer
91 views

Finding the minimal polynomial of $2\sqrt[3]{3}+\sqrt[3]{4}$ in the most efficient way .

4 votes
0 answers
406 views

Is there a way to find the subfields of a Galois extension without knowing the subgroup structure of the corresponding Galois group?

3 votes
0 answers
37 views

Is my line of reasoning correct for considering this fixed field as a simple extension over $GF(7)$?

3 votes
1 answer
259 views

Questions on a proof to show if $\Phi(n)=\sum^n_{i=1}\phi(i)$, where $\phi$ is the Euler phi function then $\Phi(n)=\tfrac{3n^2}{\pi}+O(n\log(n))$

3 votes
1 answer
356 views

Clarification on Möbius inversion formula proof.

3 votes
1 answer
953 views

Is a group with order $3^3\cdot 5\cdot 7$ possible?

3 votes
1 answer
52 views

Two questions regarding this proof from my notes which shows that if $H$ is normal in $G$ and $G$ is solvable then $\tfrac{G}{H}$ is solvable

3 votes
1 answer
39 views

Deducing which elements of $\Bbb U_{20}$ generate its subgroups given that we know the subgroup structure of $C_4\times C_2$

3 votes
0 answers
50 views

Why isn't my choice of element fixed by the automorphism of this subgroup of $Gal(\Bbb Q(w_{20})/Q)$?

3 votes
1 answer
72 views

Questions on the formulation of this proof showing an extension is simple if and only if there are finitely many intermediate fields.

3 votes
2 answers
95 views

A general question on Galois theory: cyclotomy

3 votes
2 answers
491 views

why do we need $4$ dimensions to embed a two dimensional shape on a surface

3 votes
1 answer
2k views

Find the minimal polynomial of a root involving cubed roots

3 votes
2 answers
354 views

Galois $\text{GF}(5)$, does $α^4=2$ make any sense?

3 votes
2 answers
1k views

What am I doing wrong while finding the Laurent series of $\frac{1}{\sin(z)}$? [duplicate]

2 votes
1 answer
33 views

what is the best approach to show that F is complex differentiable?

2 votes
2 answers
172 views

Number of elements of the same cycle type in $S_5$, is this the correct way to think about the combinatorics?

2 votes
3 answers
296 views

How does one compute the reciprocal of $\cos(z)=\sum_{n=0}^{\infty}(-1)^n\frac{z^{2n}}{2n!}$

2 votes
0 answers
206 views

How to determine all points for which a function f(z) is holomorphic?

2 votes
2 answers
83 views

Is there a more expeditious way to solve this contour integral?

2 votes
3 answers
360 views

How to compute Laurent series?

2 votes
1 answer
107 views

How much do you need to prove when finding splitting fields?

2 votes
1 answer
680 views

A minimal generating set of the Quaternions?

2 votes
2 answers
482 views

trying to understand the relation between quotient rings and Field extensions

2 votes
3 answers
206 views

The best way to approximate $15^{1/4}$

2 votes
2 answers
179 views

open set wrt metric topology, what does it mean ??

2 votes
1 answer
565 views

pointwise convergence of a piecewise function with intervals dependent on n

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