数学M/S Paper 2讨论专区

harry_lim · 发表于 2-4-2009 08:47 PM

既然沒人開Math S paper 2的帖子

自己開算了

我有東西要問的

慢點我會問問題

希望大家都能回答我的問題

也歡迎各位進來這里問問題

因為我現在變成自修數學。。。所以我不會的東西就會來這里問了

我拿的3個科目都在學校有上的。。。只有數學沒有offer教

就醬

[ 本帖最后由猪头鱼于 3-5-2009 08:14 PM 编辑 ] 本帖最后由 peaceboy 于 24-9-2013 12:55 PM 编辑

无光的星星 · 发表于 5-4-2009 02:16 PM

如果我会，我就是试试解答吧。。不过事先声明，我的数学不是很好。。

Allison · 发表于 5-4-2009 04:22 PM

我来问问题咯！

deductive geometry :
1. In triangle ABC with angle BAC obtuse, the perpendicular bisectors of AB and AC meet BC at the points H & G respectively. Show that angle HAG = 2 angle BAC - 180 degree.

2. In triangle ABC, P,Q & R are points on sides AB,AC and BC respectively. If PQ//BC, QR//AB and PR//AC, show that P is the midpoint of AB.

Ivanlsy · 发表于 5-4-2009 09:03 PM

原帖由 Allison 于 5-4-2009 04:22 PM 发表
我来问问题咯！

deductive geometry :
1. In triangle ABC with angle BAC obtuse, the perpendicular bisectors of AB and AC meet BC at the points H & G respectively. Show that angle HAG = 2 angle BAC - ...

小姐~這裡是Maths S~

Allison · 发表于 5-4-2009 09:54 PM

不好意思。。。。
没留意到，只看到是paper2

有谁能够帮我解答吗？？
不知道要在哪发问才对。。。。

无光的星星 · 发表于 5-4-2009 10:07 PM

自己开贴吧。。。。。

harry_lim · 发表于 5-4-2009 10:46 PM

原帖由 Allison 于 5-4-2009 04:22 PM 发表
我来问问题咯！

deductive geometry :
1. In triangle ABC with angle BAC obtuse, the perpendicular bisectors of AB and AC meet BC at the points H & G respectively. Show that angle HAG = 2 angle BAC - ...

問到math T P2的問題

這里是MATH S P2的討論區啊

笨蛋一个 · 发表于 6-4-2009 11:00 AM

不知道要酱画出来

大概大概讲一下

1) angle BAH= angle ABH=a
angle GAC= angle GCA=b
angle AHG= 2a, angle HGA= 2b
angle HAG= 180-(2a+2b)=c
180-2(a+b+c)=-c
angle HAG= 2angle BAC -180

2) 画出来，你会发现大的三角形里有4个小三角形，而且每个三角形都similar.
用similiar triangle的property, 每个小三角形length除k，然后你会发现
AP=AB/k
PB=AB-AP=AB-AB/k=AB/k
k=2
P是AB的midpoint

Allison · 发表于 6-4-2009 01:47 PM

谢谢你的回复。。。
我明白了

harry_lim · 发表于 16-4-2009 06:16 PM

我有問題要問了

1) 5 out of 12 pieces of batik in a display were made bythe class Form 4 Sutera.If two pieces of the batik are selectedrandomly, find the probability that at least one of the pieces weremade by Form 4 Sutera.

2) A gardener planted 12 dahlias in separatepots. Out of those plants, 5 are red, 3 are yellow, 2 are purple and 2 are white. The gardener presented 4 of the plants to a friend. What isthe probability that the dahlias are
(a) of the same colour?
(b) all ofdifferent colours?

3) The registration numbers of vehicles in a certaincountry use digits 1 to 999. If a visitor has just entered the country,what is the probability that the first car he sees has at least 2 identical digits?

4) Din and Joe are among 7 finalists in quiz whichgives away 3 prizes. The first prize is a car, the second prize is amotorcycle and third prize is a television set. Assuming that allcontestants have equal chances of winning, what is the probability that Din and Joe will beempty-handed?

要寫solution出來哦

謝謝了

无光的星星 · 发表于 21-4-2009 08:48 PM

probability我最差了。。不会。。

笨蛋一个 · 发表于 21-4-2009 11:06 PM

我的probability也不是很好，加上很久没做了
有错跟我讲下