User Devendra Singh Rana

6 votes

Accepted

Four Pillars of Functional Analysis

answered Jul 15, 2018 at 6:42

5 votes

Accepted

Step Function vs Simple Function

answered Oct 20, 2017 at 16:27

4 votes

Why $A$ invertible $\iff \det A\neq 0$

answered Jun 24, 2018 at 4:57

3 votes

Accepted

Is there an equation whose solution does not exist in the complex plane?

answered Sep 3, 2017 at 6:38

3 votes

Example of group of order $p^3$

answered Dec 25, 2017 at 13:50

2 votes

A cyclic group $G$ has only one proper subgroup and it is of order $p$ (a prime). What is the order of $G$?

answered Dec 26, 2017 at 7:10

2 votes

Is $\mathbb{R}^2$ with product defined like $(x, y)\cdot(a, b)=(ax, by)$, and usual addition, a field?

answered Aug 1, 2018 at 6:24

2 votes

Accepted

Show that $d(x,y)=|x-2y|$ defines a metric on $\mathbb R$

answered Aug 16, 2018 at 18:54

2 votes

Let $V$ be a vector space. What is quotient space $V/\{0\}$?

answered Feb 20, 2018 at 6:54

2 votes

To find the eigenvalues of matrix.

answered Dec 29, 2017 at 21:02

2 votes

Range of Even Function

answered Jan 17, 2018 at 14:02

2 votes

How to determine the characteristic polynomial of the $4\times4$ real matrix of ones?

answered Jan 17, 2018 at 16:17

2 votes

$d(A,B)=\min\{ d(a,b): a\in A\text{ and }b\in B\}>0$ then $A\cup B$ is not connected

answered Sep 13, 2019 at 6:50

1 vote

Accepted

T is an open map if and only if $T^{-1}$ is continuous

answered May 18, 2020 at 10:20

1 vote

Rank of matrix - simple problem

answered Jan 26, 2018 at 8:05

1 vote

Simple 2d-graph question

answered Jan 26, 2018 at 8:24

1 vote

Accepted

Which of the following is true about $\mathbb{Q}×[0,1]$

answered Jan 3, 2018 at 6:41

1 vote

Accepted

Question about connectedness of intervals on $ \mathbb{R} $

answered Jan 15, 2018 at 15:54

1 vote

Uniform Continuity exercise

answered Jan 31, 2017 at 18:09

1 vote

Accepted

Eigenvalues of $A^tA$?

answered Jun 16, 2018 at 15:15

1 vote

Accepted

Finding the four fourth roots of $-i$ using polar form

answered Aug 20, 2018 at 9:41

1 vote

Does $\lim\limits_{x\to\infty}$ equal to $\lim\limits_{x\to+\infty}$?

answered Dec 13, 2018 at 8:18

1 vote

Accepted

If $A\in M_{m\times n}(\mathbb{R})$ and $m>n$ and $Ker(A)=0$ then $A^TA$ is invertible.

answered Dec 27, 2017 at 19:47

1 vote

Why $d(x,A)$ metric is not a set?

answered Dec 27, 2017 at 20:06

1 vote

(why) does an integrable function have to be measurable?

answered Dec 25, 2017 at 19:28

1 vote

What is matrix form of linear tranformation.

answered Oct 1, 2017 at 18:53

1 vote

Laurent series of the function at $z=0$

answered Oct 4, 2017 at 19:10

0 votes

Convergence of $\sum_{n=1}^{\infty}|x_n+y_n|$

answered Oct 20, 2017 at 16:20

0 votes

Is $\frac 10 = \infty$?

answered Dec 26, 2017 at 6:04

0 votes

Types of singularities, why is this an essential singularity

answered Dec 27, 2017 at 11:03

Stack Exchange Network

42 Answers

Four Pillars of Functional Analysis

Step Function vs Simple Function

Why $A$ invertible $\iff \det A\neq 0$

Is there an equation whose solution does not exist in the complex plane?

Example of group of order $p^3$

A cyclic group $G$ has only one proper subgroup and it is of order $p$ (a prime). What is the order of $G$?

Is $\mathbb{R}^2$ with product defined like $(x, y)\cdot(a, b)=(ax, by)$, and usual addition, a field?

Show that $d(x,y)=|x-2y|$ defines a metric on $\mathbb R$

Let $V$ be a vector space. What is quotient space $V/\{0\}$?

To find the eigenvalues of matrix.

Range of Even Function

How to determine the characteristic polynomial of the $4\times4$ real matrix of ones?

$d(A,B)=\min\{ d(a,b): a\in A\text{ and }b\in B\}>0$ then $A\cup B$ is not connected

T is an open map if and only if $T^{-1}$ is continuous

Rank of matrix - simple problem

Simple 2d-graph question

Which of the following is true about $\mathbb{Q}×[0,1]$

Question about connectedness of intervals on $ \mathbb{R} $

Uniform Continuity exercise

Eigenvalues of $A^tA$?

Finding the four fourth roots of $-i$ using polar form

Does $\lim\limits_{x\to\infty}$ equal to $\lim\limits_{x\to+\infty}$?

If $A\in M_{m\times n}(\mathbb{R})$ and $m>n$ and $Ker(A)=0$ then $A^TA$ is invertible.

Why $d(x,A)$ metric is not a set?

(why) does an integrable function have to be measurable?

What is matrix form of linear tranformation.

Laurent series of the function at $z=0$

Convergence of $\sum_{n=1}^{\infty}|x_n+y_n|$

Is $\frac 10 = \infty$?

Types of singularities, why is this an essential singularity