# Liu Gang

less info
reputation
425
bio website math.stackexchange.com/users/… location France age 25 member for 11 months seen 1 hour ago profile views 248

like learning everything

 44 Where did the negative answer come from? 18 How to solve the inequality $x^2>10$ using square roots? 10 A problem on Mean Value Theorem 8 How prove this inequality $(1+\frac{1}{16})^{16}<\frac{8}{3}$ 6 $\lim n a_n=0 \Rightarrow \sum a_n\text{ converges}$

# 3,603 Reputation

 +35 show inverse by matrix multiplication +25 Show that $\sum_{k=0}^{+\infty}ka_k=\sum_{k=0}^{+\infty}\sum_{i=k+1}^{+\infty}a_i$. +10 How to prove $\prod_{i=1}^{\infty} (1-a_n) = 0$ iff $\sum_{i=1}^{\infty} a_n = \infty$? +10 How can we apply the Borel-Cantelli lemma here?

# 10 Questions

 10 Why is $\sum_{n=-\infty}^{\infty}\exp(-(x+n)^2)$ “almost” constant? 4 A Polish space which is not locally compact 3 bounded measure and dense subset of continuous functions 3 Independence implies constancy 2 interchange stochastic and deterministic integration

# 96 Tags

 90 sequences-and-series × 24 41 inequality × 9 64 limits × 11 34 real-analysis × 24 62 algebra-precalculus × 4 33 probability × 39 44 nested-radicals 18 radicals 41 calculus × 15 17 probability-theory × 22

# 4 Accounts

 Mathematics 3,603 rep 425 Area 51 151 rep 2 Quantitative Finance 101 rep 1 French Language 101 rep 2