User Srijan

89 votes

6 answers

36k views

Not every metric is induced from a norm

asked Jul 4, 2012 at 2:31

47 votes

1 answer

28k views

How to count number of bases and subspaces of a given dimension in a vector space over a finite field? [duplicate]

asked May 8, 2012 at 11:23

44 votes

5 answers

81k views

How to generate random symmetric positive definite matrices using MATLAB? [closed]

asked Apr 11, 2013 at 5:43

37 votes

3 answers

13k views

Real numbers equipped with the metric $ d (x,y) = | \arctan(x) - \arctan(y)| $ is an incomplete metric space

asked May 31, 2012 at 22:49

32 votes

4 answers

28k views

Understanding the definition of Cauchy sequence

asked May 23, 2012 at 11:39

29 votes

4 answers

3k views

Can every nonsingular $n\times n$ matrix with real entries be made singular by changing exactly one entry?

asked May 17, 2012 at 17:04

22 votes

3 answers

34k views

Understanding weighted inner product and weighted norms

asked May 17, 2013 at 6:34

19 votes

2 answers

4k views

Intuition behind the definition of linear transformation

asked Aug 27, 2014 at 4:39

15 votes

4 answers

2k views

Understanding quotient topology

asked Apr 19, 2013 at 8:54

13 votes

2 answers

407 views

Condition on function $f:\mathbb{R}\rightarrow \mathbb{R}$ so that $(a,b)\mapsto | f(a) - f(b)|$ generates a metric on $\mathbb{R}$

asked Jun 7, 2012 at 7:11

13 votes

2 answers

15k views

Understanding equivalent metric spaces

asked May 28, 2012 at 11:59

13 votes

1 answer

11k views

Showing $(C[0,1], d_1)$ is not a complete metric space

asked May 31, 2012 at 21:53

12 votes

3 answers

1k views

What if your research paper got rejected with few comments given on paper?

asked May 26, 2012 at 2:42

12 votes

1 answer

23k views

Counting binary operations on a set with $n$ elements

asked Apr 28, 2013 at 19:45

10 votes

2 answers

4k views

Open and closed balls in $C[a,b]$

asked May 22, 2012 at 18:59

9 votes

1 answer

3k views

Understanding isometric spaces

asked May 28, 2012 at 5:34

9 votes

2 answers

836 views

What is $\frac{\det(A+tI)}{\det(B+tI)}$ as $t\to0$?

asked May 10, 2012 at 10:45

9 votes

4 answers

1k views

Find out trace of a given matrix $A$ with entries from $\mathbb{Z}_{227}$

asked May 10, 2012 at 21:29

8 votes

1 answer

1k views

Can we say that there exist an integer $n$ such $A+nB$ invertible?

asked May 10, 2012 at 6:08

8 votes

4 answers

2k views

Computing the trace and determinant of $A+B$, given eigenvalues of $A$ and an expression for $B$

asked May 11, 2012 at 13:05

8 votes

5 answers

4k views

Computing $A^{50}$ for a given matrix $A$

asked May 10, 2012 at 12:18

8 votes

1 answer

331 views

Does there exist a vector space with 30 elements?

asked May 8, 2012 at 10:17

8 votes

3 answers

2k views

Matlab code to compute the smallest nonzero singular value of the matrix without using SVD

asked Apr 12, 2017 at 9:55

8 votes

3 answers

4k views

Let $p$ be a prime. If a group has more than $p − 1$ elements of order $p$, why can’t the group be cyclic?

asked Apr 21, 2013 at 17:34

8 votes

1 answer

8k views

Convergence of the series $\sum a_n$ implies the convergence of $\sum \frac{\sqrt a_n}{n}$, if $a_n>0$ [duplicate]

asked Apr 27, 2013 at 15:02

7 votes

1 answer

563 views

$G$ is a nonabelian finite group, then $|Z(G)|\leq \frac{1}{4}|G|$

asked Apr 20, 2013 at 9:12

7 votes

1 answer

6k views

How to verify if a set admits a finite sub covering?

asked Jun 2, 2012 at 4:14

6 votes

4 answers

6k views

A be a $3\times 3$ matrix over $\mathbb {R}$ such that $AB =BA$ for all matrices $B$. what can we say about such matrix $A$ [duplicate]

asked May 9, 2012 at 7:45

6 votes

1 answer

663 views

Finding the number of analytic functions which vanish only on a given set.

asked May 13, 2012 at 6:59

6 votes

1 answer

3k views

Understanding the proof of Laurent's theorem

asked Oct 26, 2016 at 10:37

Stack Exchange Network

172 Questions

Not every metric is induced from a norm

How to count number of bases and subspaces of a given dimension in a vector space over a finite field? [duplicate]

How to generate random symmetric positive definite matrices using MATLAB? [closed]

Real numbers equipped with the metric $ d (x,y) = | \arctan(x) - \arctan(y)| $ is an incomplete metric space

Understanding the definition of Cauchy sequence

Can every nonsingular $n\times n$ matrix with real entries be made singular by changing exactly one entry?

Understanding weighted inner product and weighted norms

Intuition behind the definition of linear transformation

Understanding quotient topology

Condition on function $f:\mathbb{R}\rightarrow \mathbb{R}$ so that $(a,b)\mapsto | f(a) - f(b)|$ generates a metric on $\mathbb{R}$

Understanding equivalent metric spaces

Showing $(C[0,1], d_1)$ is not a complete metric space

What if your research paper got rejected with few comments given on paper?

Counting binary operations on a set with $n$ elements

Open and closed balls in $C[a,b]$

Understanding isometric spaces

What is $\frac{\det(A+tI)}{\det(B+tI)}$ as $t\to0$?

Find out trace of a given matrix $A$ with entries from $\mathbb{Z}_{227}$

Can we say that there exist an integer $n$ such $A+nB$ invertible?

Computing the trace and determinant of $A+B$, given eigenvalues of $A$ and an expression for $B$

Computing $A^{50}$ for a given matrix $A$

Does there exist a vector space with 30 elements?

Matlab code to compute the smallest nonzero singular value of the matrix without using SVD

Let $p$ be a prime. If a group has more than $p − 1$ elements of order $p$, why can’t the group be cyclic?

Convergence of the series $\sum a_n$ implies the convergence of $\sum \frac{\sqrt a_n}{n}$, if $a_n>0$ [duplicate]

$G$ is a nonabelian finite group, then $|Z(G)|\leq \frac{1}{4}|G|$

How to verify if a set admits a finite sub covering?

A be a $3\times 3$ matrix over $\mathbb {R}$ such that $AB =BA$ for all matrices $B$. what can we say about such matrix $A$ [duplicate]

Finding the number of analytic functions which vanish only on a given set.

Understanding the proof of Laurent's theorem