User Indrayudh Roy

8 votes

1 answer

305 views

Solving an inequality : $n \geq 3$ , $n^{n} \lt (n!)^{2}$. [duplicate]

asked May 7, 2014 at 20:22

6 votes

2 answers

335 views

Intuition behind the concept of points "near infinity" in topology

general-topology differential-topology infinity

asked Sep 10, 2016 at 22:10

5 votes

0 answers

204 views

${n \choose r}=\frac {n!}{r!(n-r)!}$ without using the permutation approach.

combinatorics induction binomial-coefficients alternative-proof

asked Jun 21, 2014 at 16:34

5 votes

3 answers

307 views

Equality in prime number inequality

elementary-number-theory

asked Jan 8, 2014 at 11:01

5 votes

2 answers

2k views

Representation as a sum of two squares

number-theory elementary-number-theory

asked Feb 21, 2014 at 15:03

4 votes

3 answers

553 views

$1992$ IMO Functional Equation problem [duplicate]

reference-request contest-math functional-equations

asked Apr 1, 2014 at 17:36

4 votes

3 answers

306 views

A question on calculus

calculus integration area

asked May 9, 2014 at 18:57

4 votes

1 answer

83 views

How to show that $Y\cup_{f} X$ is normal when $X$ and $Y$ are normal and $f:A\to Y$ is a continuous map with $A$ closed in $X$?

general-topology quotient-spaces

asked Mar 3, 2018 at 23:26

3 votes

0 answers

566 views

Please help in proving $ab=0 \space \forall a,b$ in a ring $R$ where the only right ideals of $R$ are the trivial ones and $R$ is not a division ring.

reference-request ring-theory ideals

asked Sep 16, 2015 at 22:24

3 votes

1 answer

153 views

A complex number inequality

inequality complex-numbers

asked Dec 31, 2013 at 17:21

3 votes

2 answers

150 views

A problem on a sequence

sequences-and-series combinatorics

asked Jan 16, 2014 at 17:42

3 votes

2 answers

80 views

Problem on functions

calculus real-analysis functions

asked Jan 20, 2014 at 18:05

3 votes

2 answers

129 views

Sum of series ${n\choose 2a}{a\choose 0}+ {n\choose {2a+2}}{{a+1}\choose 1} + {n\choose {2a+4}}{{a+2}\choose 2} + \ldots$

combinatorics algebra-precalculus summation binomial-coefficients

asked Sep 24, 2013 at 10:05

2 votes

1 answer

140 views

Expressing as a sum of squares.

elementary-number-theory

asked Sep 24, 2013 at 10:26

2 votes

2 answers

1k views

Are the axioms for the real numbers consistent?

logic

asked Oct 23, 2013 at 5:44

2 votes

1 answer

163 views

Prove or disprove an inequality involving statistics

probability statistics probability-theory inequality

asked Jan 21, 2014 at 14:47

2 votes

2 answers

689 views

Which integers can be expressed as a sum of squares of two coprime integers?

elementary-number-theory

asked Mar 30, 2013 at 11:09

2 votes

1 answer

834 views

Is $\tan (\pi x)$ never rational for all rational $x$ in the interval $(-0.5,0.5)$, with the exceptions occuring at $x=0, -0.25, 0.25$?

elementary-number-theory reference-request

asked Jul 26, 2013 at 11:13

2 votes

2 answers

438 views

Odd and even functions.

functions reference-request definition

asked Apr 10, 2014 at 14:58

2 votes

0 answers

108 views

A Proof-Library

reference-request soft-question

asked Feb 19, 2014 at 16:40

2 votes

1 answer

72 views

Is it true that $\varinjlim\left( A_{i}\times B\right)\cong \left(\varinjlim A_{i}\right)\times B$ in topological spaces?

general-topology continuity

asked Feb 8, 2019 at 9:52

1 vote

0 answers

69 views

Let $M_{0}:=\{f \in C[0,1] \mid f(0)=0 \}$. Show that $M_0$ is not a finitely generated ideal of $C[0,1]$.

ring-theory ideals

asked Aug 16, 2016 at 21:17

1 vote

2 answers

157 views

Does radical ideals $\sqrt{I_1}\subseteq\sqrt{I_2}\cdots$ becoming stationary imply ideals $I_1\subseteq I_2\cdots$ becoming stationary?

ring-theory commutative-algebra modules noetherian

asked Feb 5, 2017 at 6:28

1 vote

4 answers

150 views

A Horrible looking limit

calculus limits

asked Apr 22, 2014 at 15:16

1 vote

1 answer

61 views

Perhaps similar number theory problems

number-theory divisibility

asked Feb 15, 2014 at 17:23

1 vote

2 answers

136 views

Please find the mistake [duplicate]

algebra-precalculus

asked Dec 17, 2013 at 13:51

0 votes

2 answers

381 views

Laws of indices

algebra-precalculus definition

asked Dec 20, 2013 at 17:38

0 votes

1 answer

127 views

Rationals, irrationals and Continuity

real-analysis continuity

asked Feb 6, 2014 at 10:52

0 votes

1 answer

127 views

$\lim_{n\rightarrow \infty} \frac {(n!)^{\frac {1}{n}}}{n}$ and $\lim_{n\rightarrow \infty} \frac {1}{n}\ln {2n \choose n}$

calculus limits

asked Feb 26, 2014 at 19:53

0 votes

1 answer

64 views

Help in proving that arc-connectedness is an equivalence relation in non-Hausdorff spaces.

general-topology reference-request equivalence-relations

asked Apr 4, 2017 at 10:59

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32 Questions

Solving an inequality : $n \geq 3$ , $n^{n} \lt (n!)^{2}$. [duplicate]

Intuition behind the concept of points "near infinity" in topology

${n \choose r}=\frac {n!}{r!(n-r)!}$ without using the permutation approach.

Equality in prime number inequality

Representation as a sum of two squares

$1992$ IMO Functional Equation problem [duplicate]

A question on calculus

How to show that $Y\cup_{f} X$ is normal when $X$ and $Y$ are normal and $f:A\to Y$ is a continuous map with $A$ closed in $X$?

Please help in proving $ab=0 \space \forall a,b$ in a ring $R$ where the only right ideals of $R$ are the trivial ones and $R$ is not a division ring.

A complex number inequality

A problem on a sequence

Problem on functions

Sum of series ${n\choose 2a}{a\choose 0}+ {n\choose {2a+2}}{{a+1}\choose 1} + {n\choose {2a+4}}{{a+2}\choose 2} + \ldots$

Expressing as a sum of squares.

Are the axioms for the real numbers consistent?

Prove or disprove an inequality involving statistics

Which integers can be expressed as a sum of squares of two coprime integers?

Is $\tan (\pi x)$ never rational for all rational $x$ in the interval $(-0.5,0.5)$, with the exceptions occuring at $x=0, -0.25, 0.25$?

Odd and even functions.

A Proof-Library

Is it true that $\varinjlim\left( A_{i}\times B\right)\cong \left(\varinjlim A_{i}\right)\times B$ in topological spaces?

Let $M_{0}:=\{f \in C[0,1] \mid f(0)=0 \}$. Show that $M_0$ is not a finitely generated ideal of $C[0,1]$.

Does radical ideals $\sqrt{I_1}\subseteq\sqrt{I_2}\cdots$ becoming stationary imply ideals $I_1\subseteq I_2\cdots$ becoming stationary?

A Horrible looking limit

Perhaps similar number theory problems

Please find the mistake [duplicate]

Laws of indices

Rationals, irrationals and Continuity

$\lim_{n\rightarrow \infty} \frac {(n!)^{\frac {1}{n}}}{n}$ and $\lim_{n\rightarrow \infty} \frac {1}{n}\ln {2n \choose n}$

Help in proving that arc-connectedness is an equivalence relation in non-Hausdorff spaces.