Timothy Leung
  • Member for 8 years, 9 months
  • Last seen more than 1 year ago
2 answers
7 votes
2k views
1 bookmarks
Simplify $\sum_{k=1}^{n} {k\choose m} {k}$
2 answers
5 votes
5k views
1 bookmarks
How to know a function is integrable or not?
6 answers
5 votes
2k views
Is this series convergent? $\sum_{i=1}^{\infty} \frac{(\log n)^2}{n^2}$
1 answers
4 votes
1k views
If a series is absolutely converge then the series can be regroup with changing their order?
1 answers
3 votes
1k views
1 bookmarks
Find the generating function for the sequence ${1, 2, 1, 4, 1, 8, ...}$
4 answers
3 votes
110 views
Prove $a^n \rightarrow 0$ as $n \rightarrow \infty$ for $\left|a\right| < 1$ without use of log properties
1 answers
2 votes
189 views
If $x,y$ are elements of $\mathbb{R}$ and $x>0$ then there is a positive integer $n$ s.t. $nx > y$
2 answers
2 votes
128 views
Concept about series test
1 answers
2 votes
1k views
If $pq=1$, then $p=q=1$ for $p,q \in \mathbb {Z}, p,q >0$
1 answers
2 votes
122 views
show by induction if there exists a $n_0 \in \mathbb N $such that $n\geq n_0 , n! \gt 2n^3$
0 answers
2 votes
46 views
Two methods to prove the sequence is monotonic?
1 answers
1 votes
38 views
Confusion using Multiplication rule in probabilty
1 answers
1 votes
217 views
Prove number of prime factors $p$ in $n!$
1 answers
1 votes
74 views
Determine the number of n-term sequences of 0s and 1s containing no two consecutive $0$s
1 answers
1 votes
77 views
Find the coefficient of $x^{4}$ in $(1+x)^{\frac{1}{3}}$
2 answers
1 votes
120 views
Show $x+\frac{\lambda}x \geq 2\sqrt{\lambda}$ all $x,\lambda>0$
4 answers
1 votes
387 views
Show if $x^2$ is divisible by $5$ then $x$ is divisible by $5$ as well
1 answers
1 votes
103 views
If $\forall \epsilon >0$ there is no element in $S$ greater than $s$ and $\exists$ element in $S$ greater than $s-\epsilon$, then $s$ is the supremum
2 answers
0 votes
654 views
2 bookmarks
Prove that $\int_{-\infty}^{\infty} \sin x \, dx = 0 $
1 answers
0 votes
36 views
compute $\sum_{I\subseteq K }(-1)^{\mid K\setminus I\mid}$
2 answers
0 votes
68 views
1 bookmarks
If $E = \{ x \in \mathbb{R}: \sin(\frac1{x}) = 1\}$ then $l = 0$ is a limit point of E
3 answers
0 votes
87 views
Let $a,b \in \Re$. If 0 < $\epsilon$ < min{|a|, |b|}. Show this inequality