# Quod Erat Demonstrandum

## 2010/10/28

### 3 idiots

Filed under: Fun,Life,Report — johnmayhk @ 2:14 下午

3 Idiots-Give Me Some Sunshine Promo Video Exclusive

## 2010/10/27

### Proof of Lagrange’s formula

Filed under: NSS,University Mathematics — johnmayhk @ 12:55 下午

by using Einstein notation

(from Lok)

### 玩玩系列：二次方程

Filed under: HKALE,NSS,Pure Mathematics — johnmayhk @ 10:11 上午

1. 設 $a,b,c$ 是奇數（odd numbers），證明 $ax^2 + bx + c = 0$ 無整數根（integral root）。
2. 已知 $e$$\pi$ 是超越數，證明 $e + \pi$$e\pi$ 兩者中起碼一個是超越數。

## 2010/10/26

### [FW] Stephen Wolfram: Computing a theory of everything

Filed under: Fun,Report — johnmayhk @ 8:39 上午
Tags:

Stephen Wolfram, creator of Mathematica, talks about his quest to make all knowledge computational — able to be searched, processed and manipulated. His new search engine, Wolfram Alpha, has no lesser goal than to model and explain the physics underlying the universe.

Watch the presentation at
http://www.ted.com/talks/lang/eng/stephen_wolfram_computing_a_theory_of_everything.html

WolframAlpha 給我提供答案，也給我未想過的問題。

## 2010/10/25

Filed under: Fun,Report — johnmayhk @ 9:35 上午

## 2010/10/24

### M2 某短題

Filed under: NSS — johnmayhk @ 6:43 下午

（其實那是充要條件）

## 2010/10/21

### 因式分解二次多項式

Filed under: NSS — johnmayhk @ 5:37 下午
Tags: ,

$ax^2 + bx + c \equiv a(x - \alpha)(x - \beta)$ ………. (*)

$ax^2 + bx + c \equiv ax^2 - a(\alpha + \beta)x + a\alpha\beta$

$\alpha + \beta = \frac{-b}{a}$
$\alpha\beta = \frac{c}{a}$

## 2010/10/18

### 某插值法習題

Filed under: Additional / Applied Mathematics,HKALE — johnmayhk @ 2:56 下午
Tags:

$f(x) = \sin(\frac{\pi}{2}x)$

## 2010/10/13

### 不能秒殺的提問

Filed under: Pure Mathematics — johnmayhk @ 7:33 上午

## 2010/10/12

### [FW] When Even Mathematicians Don’t Understand the Math

Filed under: Fun,Report — johnmayhk @ 7:25 上午

When Even Mathematicians Don’t Understand the Math

By SUSAN KRUGLINSKI

Published: May 25, 2004

To most of us, smudgy white mathematical scrawls covering a blackboard epitomize incomprehensibility. The odd symbols and scattered numerals look like a strange language, and yet to read them, neurologists tell us, we would have to use parts of our brains that have nothing to do with what we normally think of as reading and writing. (more…)

## 2010/10/11

### 666

Filed under: Fun,Report — johnmayhk @ 9:58 上午

【一】

$666 = 1^3 + 2^3 + 3^3 + 4^3 + 5^3 + 6^3 + 5^3 + 4^3 + 3^3 + 2^3 + 1^3$

【二】 (more…)

## 2010/10/10

### 剪報：數學家獎項

Filed under: Report — johnmayhk @ 2:35 下午

2010-10-06 明報 (more…)

## 2010/10/09

### [RTHK] 簡介量子電腦

Filed under: Physics,Report — johnmayhk @ 9:02 下午

49:25 開始 52:33 結束

http://en.wikipedia.org/wiki/Quantum_computer

## 2010/10/06

### 教學碎念

Filed under: NSS,Pure Mathematics — johnmayhk @ 3:22 下午

1.

（他們笑我出卷容易，因自己功力有限，我求他們見諒。）

## 2010/10/03

### [FW] 你的心不是公廁 ——禁絕虛幻世界的實驗報告

Filed under: Life — johnmayhk @ 5:58 下午

[FW] 你的心不是公廁 ——禁絕虛幻世界的實驗報告

(明報)2010年10月3日 星期日 05:05