User 000

154 votes

15 answers

55k views

Are there real-life relations which are symmetric and reflexive but not transitive?

elementary-set-theory relations

asked Jan 1, 2013 at 18:17

16 votes

4 answers

2k views

Donald Knuth's summation notation confuses me.

sequences-and-series notation

asked May 16, 2012 at 5:13

14 votes

4 answers

686 views

Is there a closed form for the series $\sum_{k=1}^\infty \frac{\ln(4k-3)}{(4k-3)}-\frac{\ln(4k-1)}{(4k-1)}?$

sequences-and-series

asked Dec 8, 2012 at 7:35

12 votes

1 answer

1k views

What is $f(x)$ divided by $(x-a)$?

algebra-precalculus sequences-and-series polynomials

asked Jan 14, 2012 at 19:12

10 votes

5 answers

1k views

What is the coefficient of the $x^3$ term in the expansion of $(x^2+x-5)^7$ (See details)?

combinatorics algebra-precalculus multinomial-coefficients

asked Sep 22, 2012 at 0:21

8 votes

3 answers

7k views

Proving that $S_n$ has order $n!$

group-theory induction symmetric-groups

asked Jun 10, 2012 at 0:08

8 votes

2 answers

4k views

Is there a unique solution for this quadratic matrix equation?

linear-algebra matrices matrix-equations

asked Jan 3, 2012 at 4:16

8 votes

3 answers

203 views

How do I read this question? (subject: bijections)

functions elementary-set-theory

asked Dec 29, 2012 at 0:43

6 votes

2 answers

2k views

Proving a commutative ring can be embedded in any quotient ring.

abstract-algebra ring-theory

asked Jun 23, 2012 at 6:19

6 votes

1 answer

2k views

Is this a correct proof that all rational functions are integrable?

polynomials integration rational-functions

asked Apr 19, 2012 at 22:49

5 votes

1 answer

219 views

Implicit Differentiation of $x^2y+y^5\sec(x)=5$.

calculus implicit-differentiation

asked Nov 21, 2012 at 18:01

4 votes

3 answers

4k views

Probability of 15 consecutive green lights

probability applications

asked Nov 29, 2012 at 21:48

4 votes

1 answer

3k views

Solution Sets of Trigonometric Equations

trigonometry galois-theory

asked Nov 16, 2012 at 23:43

4 votes

3 answers

1k views

What is the limit of a sequence defined recursively as $x_1=2$, $x_{n+1}=\frac{1}{3-x_n}$ with $n \in \mathbb{N}$, and how do I prove it exists?

real-analysis sequences-and-series limits

asked Jan 25, 2013 at 17:49

3 votes

1 answer

634 views

Why does $\frac{s}{s-1} > \zeta(s) > \frac{1}{s-1}$ imply $\lim_{s \to 1^{+}}(s-1)\zeta(s)=1$?

limits riemann-zeta

asked Apr 19, 2012 at 11:01

2 votes

1 answer

79 views

$n^s=(n)_s+f(s)$, what is $f(s)$?

algebra-precalculus factorial

asked Apr 11, 2012 at 18:19

2 votes

1 answer

71 views

What is a more natural example of the following?

abstract-algebra

asked Oct 21, 2012 at 20:33

2 votes

2 answers

239 views

Is $\left|\left[\frac{1}{7,000,000,000},1\right]\right|<\left|[0,1]\right|$?

elementary-set-theory

asked Feb 2, 2013 at 21:47

1 vote

1 answer

132 views

How can one differentiate with respect to variable upperbounds in summations?

calculus derivatives summation

asked Feb 28, 2015 at 6:44

0 votes

1 answer

72 views

Laplace transform identity: $\mathcal{L}[f^{(n)}(t)/t^m](s)=?$

ordinary-differential-equations laplace-transform

asked Apr 29, 2018 at 1:56

0 votes

1 answer

153 views

Does every equivalence relation on set $S$ containing binary relation $C$ contain equivalence relation $E$?

abstract-algebra equivalence-relations

asked Nov 6, 2012 at 22:02

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21 Questions

Are there real-life relations which are symmetric and reflexive but not transitive?

Donald Knuth's summation notation confuses me.

Is there a closed form for the series $\sum_{k=1}^\infty \frac{\ln(4k-3)}{(4k-3)}-\frac{\ln(4k-1)}{(4k-1)}?$

What is $f(x)$ divided by $(x-a)$?

What is the coefficient of the $x^3$ term in the expansion of $(x^2+x-5)^7$ (See details)?

Proving that $S_n$ has order $n!$

Is there a unique solution for this quadratic matrix equation?

How do I read this question? (subject: bijections)

Proving a commutative ring can be embedded in any quotient ring.

Is this a correct proof that all rational functions are integrable?

Implicit Differentiation of $x^2y+y^5\sec(x)=5$.

Probability of 15 consecutive green lights

Solution Sets of Trigonometric Equations

What is the limit of a sequence defined recursively as $x_1=2$, $x_{n+1}=\frac{1}{3-x_n}$ with $n \in \mathbb{N}$, and how do I prove it exists?

Why does $\frac{s}{s-1} > \zeta(s) > \frac{1}{s-1}$ imply $\lim_{s \to 1^{+}}(s-1)\zeta(s)=1$?

$n^s=(n)_s+f(s)$, what is $f(s)$?

What is a more natural example of the following?

Is $\left|\left[\frac{1}{7,000,000,000},1\right]\right|<\left|[0,1]\right|$?

How can one differentiate with respect to variable upperbounds in summations?

Laplace transform identity: $\mathcal{L}[f^{(n)}(t)/t^m](s)=?$

Does every equivalence relation on set $S$ containing binary relation $C$ contain equivalence relation $E$?