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erfink's user avatar
erfink's user avatar
erfink
  • Member for 7 years, 8 months
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74 votes

Hilbert's hotel: why can't I repeat it infinitely many times?

30 votes

The need for the Gram–Schmidt process

16 votes
Accepted

How exactly does Knuth's Up-Arrow notation work?

14 votes

Determinant of a matrix with diagonal entries $a$ and off-diagonal entries $b$

10 votes

What exactly is calculus?

10 votes

Unexpected use of topology in proofs

8 votes

are there any matrices that act like the identity matrix but are totally different?

7 votes

Why can a system of linear equations be represented as a linear combination of vectors?

7 votes

The level of knowledge needed for graduate study

7 votes
Accepted

What is the Correct Math Notation for - "For all $i=1$ to $n$"

6 votes
Accepted

What is the intuition behind the line integral for the center of mass?

5 votes

What are the vectors of $\mathbb{R}^5$ that are fixed by an element of a cyclic subgroup of $S_5$ (by the usual action)

5 votes
Accepted

How does this integration work when solving a DE?

5 votes

Is there always an answer to "what is the next number in the sequence"

5 votes
Accepted

Classification of critical points for two variables -- determinant vs definiteness

5 votes
Accepted

Motivation behind matrix diagonalisation

5 votes
Accepted

A misunderstanding on the independence of orientation of line integrals?

5 votes

Dynamical systems for pure mathematicians?

4 votes

Fundamental theorem of line integrals, what if the curl DOESN'T equal 0?

4 votes
Accepted

Misunderstanding With Basic One-To-One Set Theory

4 votes

If $T$ is linear, show that for any $\epsilon>0$, the behavior of $T$ on $B(\textbf{0}_n,\epsilon)$ determines the behavior of $T$ everywhere.

4 votes
Accepted

every point in $\mathbb{N}$ are isolated point, How?

4 votes
Accepted

find $\lim_{(x,y)\to (0,0)} \frac{x^2y^2}{x^4+y^4}$

4 votes

How do you determine the boundary curve for Stokes' Theorem

4 votes
Accepted

Why does this limit exist?

3 votes
Accepted

prove a sequence of functions converges but its derivative does not converge

3 votes
Accepted

Open cover of sequentially compact set in metric space has a Lebesgue number

3 votes

Solve $\lim_{x \rightarrow \infty}\frac{\ln(x+1)-\ln(x)}{x}$ without using L'Hopital or Taylor Series

3 votes

Why can't all instances of vector fields be integrated?

3 votes
Accepted

Prove that T is an orthonormal basis if transition matrix from S to T is orthogonal

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