# Quod Erat Demonstrandum

## 2010/05/31

### 兩名美國數學家在五月相繼離世

Filed under: Report — johnmayhk @ 11:12 下午

Martin Gardner（October 21, 1914 – May 22, 2010）
http://en.wikipedia.org/wiki/Martin_Gardner

Walter Rudin（May 2, 1921 – May 20, 2010）
http://en.wikipedia.org/wiki/Walter_Rudin

## 2010/05/28

Filed under: Report — johnmayhk @ 12:48 下午

## 2010/05/27

### [FW] 丘成桐：從明治維新到二戰前後中日數學人才培養之比較

Filed under: Report,University Mathematics — johnmayhk @ 6:10 下午
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May be an interesting article, just post the links for reference.

Text on 科學網 (2010-02-03)
http://news.sciencenet.cn/htmlnews/2010/2/228034.shtm?id=228034

PDF file from 科學時報

### just answer a textbook question from my student

Filed under: Additional / Applied Mathematics,HKALE — johnmayhk @ 12:45 下午
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To Lau (my student)

This is the question you’d asked

“A man lives at A and works at C, and is due at work at 8:30 a.m. He always catches the first train from A to B, which is scheduled to arrive at B at 8:15 a.m. Buses leaves B for C every 20 minutes, and the bus which leaves B at 8:20 a.m. is scheduled to arrive outside the factory at C at 8:27 a.m. The train is, on the average, one minute late and has a standard deviation of 4 minutes. The bus always leaves on time, but is, on the average, 1.5 minutes late with a standard deviation of 2 minutes. The man’s employer leaves home in his car at 8:15 a.m. and the time for his journey has mean value 13 minutes with a standard deviation of 3 minutes. Find the probability that the employer arrives before the employee." (more…)

## 2010/05/26

### 無聊一談

Filed under: Life,Report — johnmayhk @ 3:54 下午

http://programme.rthk.org.hk/rthk/tv/programme.php?name=tv/digital&d=2010-05-25&p=4805&e=108782&m=episode

## 2010/05/25

### [FW] 新數站

Filed under: Information — johnmayhk @ 3:38 下午

http://www.hkms-nss.net/website/index.php

## 2010/05/24

### 某詩歌某思緒

Filed under: Life — johnmayhk @ 6:14 下午
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## 2010/05/21

### [FW][SONG] 一無所有

Filed under: Fun — johnmayhk @ 10:16 下午
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「我要給你我的追求，

## 2010/05/18

### 四邊形的面積

Filed under: mathematics — johnmayhk @ 9:16 上午
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## 2010/05/16

### 空集族

Filed under: Pure Mathematics — johnmayhk @ 11:38 下午
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$A_1 = \{ a,b,c,d \}$
$A_2 = \{ b,c,d,e \}$
$A_3 = \{ c,d,e,f \}$

$A_1 \cup A_2 \cup A_3 = \{ a,b,c,d,e,f \}$ (more…)

## 2010/05/15

### 投票站，投注站

Filed under: Uncategorized — johnmayhk @ 12:13 下午

## 2010/05/14

### 我們這一班：F.4D

Filed under: Fun,School Activities — johnmayhk @ 12:19 上午

## 2010/05/13

### Trivial sharing on trigonometry

Filed under: Additional / Applied Mathematics,mathematics,NSS — johnmayhk @ 7:33 上午
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What’s wrong with the following steps?

$\sin\theta < 0$

$\Rightarrow \theta$ lies in the 3rd or 4th quadrant (more…)

## 2010/05/11

### 無聊中四數學課紀錄：(1 + 1/n)^n

Filed under: NSS,Teaching — johnmayhk @ 10:57 下午
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$e = \displaystyle\lim_{n \rightarrow \infty}(1 + \frac{1}{n})^n$

(a) $\displaystyle\lim_{n \rightarrow \infty}(1 + \frac{1}{2n})^{2n} = ?$ (more…)