Stack Exchange
log in
chat
meta
about
Stack Exchange
All Sites
Hot Questions
Top Users
Newsletters
Blogs
Cortizol
top
accounts
reputation
activity
favorites
subscriptions
Top Questions
20
votes
Evaluate $\sum_{k=1}^{\infty} \frac{k^2-1}{k^4+k^2+1}$
calculus
real-analysis
sequences-and-series
asked Feb 15 at 14:38
math.stackexchange.com
10
votes
Using $\bigvee$ and $\bigwedge$ instead $\exists$ and $\forall$
notation
predicate-logic
asked Mar 21 at 18:17
math.stackexchange.com
6
votes
Find $\sum\limits_{k\, \text{ odd}} \frac{2(k^2-1)}{k^4+k^2+1}$
calculus
real-analysis
sequences-and-series
asked Feb 19 at 19:20
math.stackexchange.com
6
votes
How to show that $(\mathbb{Q}(\sqrt{2}))^{\times} \cong (\mathbb{Q}(\sqrt{3}))^{\times}$
abstract-algebra
field-theory
asked Mar 20 at 21:06
math.stackexchange.com
5
votes
How to solve $y(y'+3)=ax^2+bx+c, \quad a,b,c \in \mathbb{R}$
differential-equations
asked Feb 28 at 14:39
math.stackexchange.com
Top Answers
8
Find $\lim\limits_{n \rightarrow \infty}\dfrac{\sin 1+2\sin \frac{1}{2}+\cdots+n\sin \frac{1}{n}}{n}$
math.stackexchange.com
7
Find $\sum\limits_{k\, \text{ odd}} \frac{2(k^2-1)}{k^4+k^2+1}$
math.stackexchange.com
6
Evaluating $\int \frac{1}{{x^4+1}} dx$
math.stackexchange.com
Stack Exchange works best with JavaScript enabled
math.stackexchange.com
