# Quod Erat Demonstrandum

## 2011/10/25

### [Old news] 新高中課程欠規劃 M1M2退修率7成

Filed under: NSS,Report — johnmayhk @ 4:06 上午

2011-10-19

■M1及M2課時不足，以致須額外補課，再加上課程對升讀大學重要性下降，爆發學生退修潮。 (more…)

## 2011/10/18

### Chain rule

Filed under: HKALE,NSS,Pure Mathematics,Teaching — johnmayhk @ 4:29 上午
Tags: ,

## 2011/10/17

### 某題

Filed under: NSS — johnmayhk @ 6:28 上午

1.猜想；
2.證明；
3.偶數有類似情況嗎？

## 2011/10/16

### 無聊改卷後2

Filed under: NSS — johnmayhk @ 2:40 下午

https://johnmayhk.wordpress.com/2011/10/12/boring-chatting-after-marking-paper/

## 2011/10/15

### 生活中的「化學」

Filed under: Fun — johnmayhk @ 7:41 上午
Tags:

（圖片來源：顏冊轉載）

## 2011/10/14

### 旋轉體體積

Filed under: HKALE,NSS,Pure Mathematics — johnmayhk @ 7:47 上午

## 2011/10/13

### 無聊改卷中

Filed under: NSS — johnmayhk @ 5:51 上午

## 2011/10/12

### 無聊改卷後

Filed under: NSS — johnmayhk @ 2:40 下午

Solve $2(x^6+\frac{1}{x^6})-5(x^2+\frac{1}{x^2})=21$ for real $x$.

(Answer: $\pm \frac{1\pm \sqrt{5}}{2}$)

## 2011/10/10

### 錯在哪裡之 0 = 1

Filed under: HKALE,NSS,Pure Mathematics — johnmayhk @ 5:29 上午
Tags:

Old stuff…

$\int \frac{\cos \theta d\theta}{\sin \theta}$

$=\int \frac{d\sin \theta}{\sin \theta}$ (more…)

## 2011/10/06

### 被 6 整除

Filed under: NSS,Pure Mathematics — johnmayhk @ 2:38 下午
Tags:

$\displaystyle \sum_{k=1}^nk=\frac{n(n+1)}{2}$

$\displaystyle \sum_{k=1}^nk^2=\frac{n(n+1)(2n+1)}{6}$

## 2011/10/04

### 純數堂無聊一記

Filed under: HKALE,Pure Mathematics — johnmayhk @ 4:23 下午

$|\int_0^x(x-t)^mf^{(m+1)}(t)dt| \le\int_0^x|(x-t)^mf^{(m+1)}(t)|dt$ ($\forall x \in \mathbb{R}$)

## 2011/10/03

### 無題

Filed under: Additional / Applied Mathematics,HKCEE,NSS — johnmayhk @ 7:39 下午

Refer to the figure, the shaded region shown is bounded by the curves $y=\sin (2x)$ and $y=2\cos x$. Find the area of the shaded region.

## 2011/10/01

### 小心切線

Filed under: Additional / Applied Mathematics,HKCEE,NSS — johnmayhk @ 9:02 上午
Tags:

Find the equation of tangent to the curve

$x^3+x^2y-2x^2+xy^2-2xy+x+y^3+y=0$ ………. (*)

at (1,0).