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fretty
  • Member for 12 years, 1 month
  • Last seen more than 2 years ago
143 votes
Accepted

A matrix and its transpose have the same set of eigenvalues/other version: $A$ and $A^T$ have the same spectrum

36 votes

Is any finite-dimensional extension of a field, say $F$, algebraic and finitely generated?

28 votes
Accepted

What do ideles and adeles look like?

24 votes
Accepted

Elementary results from Algebraic Number Theory

20 votes

How to read a book in mathematics?

18 votes
Accepted

Show that the roots of the polynomial $x^4 - px^3 + qx^2 - pqx + 1 = 0$ satisfy a certain relationship

13 votes
Accepted

Number of integer solutions of $\frac{1}{x} + \frac{1}{y} = \frac{1}{1000}$

12 votes

Examples of infinite groups such that all their respective elements are of finite order.

11 votes
Accepted

Fibonacci's final digits cycle every 60 numbers

10 votes

How to teach mathematical induction?

10 votes

What is the total number of combinations of 5 items together when there are no duplicates?

9 votes

Intuition behind "ideal"

8 votes
Accepted

Calculate integral of $ \int\sin^2(mx) \,dx$.

8 votes

Let F be a finite field with n elements. Prove $x^{n-1}=1$ for all nonzero x in F.

8 votes

For any $n \geq 1$, prove that there exists a prime $p$ with at least n of its digits equal to $0$

8 votes

How to think of the field $F(\alpha)$

8 votes

How are mathematicians taught to write with such an expository style?

8 votes
Accepted

trace of the matrix $I + M + M^2$ is

8 votes

How to show that $\cos\frac{2\pi}{n} + \cos\frac{4\pi}{n} + \ldots+ \cos\frac{2\pi(n-1)}{n} = -1$ for all positive integers $n$?

8 votes

Show that if $r$ is an nth root of $1$ and $r\ne1$, then $1 + r + r^2 + ... + r^{n-1} = 0$.

7 votes

Difference between span and basis

7 votes
Accepted

Proving that if $A^n = 0$, then $I - A$ is invertible and $(I - A)^{-1} = I + A + \cdots + A^{n-1}$

7 votes

What remains in a student's mind

7 votes

Number of elements of a finite field

7 votes
Accepted

Number of $4 $ digit numbers with no repeated digit.

7 votes

Newbie: Group Representation $\Leftrightarrow$ Left Module over the Group Ring

6 votes
Accepted

How can I evaluate an expression like $\sin(3\pi/2)$ on a calculator and get an answer in terms of $\pi$?

6 votes

Special privilege enjoyed by Elliptic Curves with Complex Multiplication

6 votes

How to find $x$ if $ x^5 \equiv 7 \pmod {13} $

6 votes
Accepted

Puzzle: concatenation is three times product

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