数学T paper 2讨论专区

Euclidzz

不用客气。。。

destiny92

sry...may i ask for math t 2007 trial question?

Euclidzz

Just ask... we willing to do the question.

cheesit92

你误会了destiny92 的意思吧?呵呵

destiny92

想问下谁有stpm trial 2007?

永遠愛著許瑋倫

A group of students sit for both the Physics and Mathematics papers in STPM.Their results are summarised as below.
75% pass mathematics
70% pass physics
40% fail in at least one of the subjects.
A student is selected randomly from the group.
(a)Find the prob. that the student passes only one of the two subjects.
(b)Among those who pass Mathmatics,find the prob that they also pass Physics.
哪位高手可以请教下

cheesit92

given data:
1.  75% pass Maths
2.  70% pass Physics
3.  40% atleast fail one sub
4.  from 3. we conclude that 60% pass both subject
(a)by Venn's diagram, 0.75 for maths, 0.70 for physics, and their intercepting area is 0.6, use M + P - intercept part..., u now finding MUP-MnP, try xia....

(b) P(P|M)=(P(PnM))/P(M)= 0.6/0.75

乖学生

A tank contains 10kg of sodium hydroxide in 1000 litres of water. Water is continuously added to the tank at a rate of 5 litres/min so that the mixture is diluted evenly. At the same time, the solution flows out at the same rate. Initially, there were 10g of NaOH in every litre of water. How long will it take for the concentration of the solution to drop to 3.2g/litre?
hlp me solve it~~TQ^^

Euclidzz

红姐

问下哦～我要画histogram, it got 0-20, its class interval is -0.5--20.5? 是这样吗？我要算frequency density 和画histogram 都是用-0.5--20.5 吗？

xiiao-giraffe

求助 >＜
If F(x)=   ∫  from 1 to x  f(x) dt, where f(t)= ∫ 1 to t^2  [sqrt (1+u^4) ] /u  du, find F'' (2)

oceanheng

2009年STPM

A boat is travelling at 30 knots . A yacht is sailing northwards at a speed of 10 knots . At 1300 , the boat is 14 nautical miles to the nort-east of the yacht
a. Determine the direction in which the boat should be travelling in order to intercept the yatch
b. At what time does the interception occur

怎樣知道 _BV_Y 的direction 是S 45 W

puangenlun

If F(x)=   ∫  from 1 to x  f(x) dt, where f(t)= ∫ 1 to t^2  [sqrt (1+u^4) ] /u  du, find F'' (2)

since
F'=f
f'=[sqrt (1+u^4) ] /u

so F"=[sqrt (1+u^4) ] /u
F'' (2)=......

puangenlun

A boat is travelling at 30 knots . A yacht is sailing northwards at a speed of 10 knots . At 1300 , the boat is 14 nautical miles to the nort-east of the yacht
a. Determine the direction in which the boat should be travelling in order to intercept the yatch
b. At what time does the interception occur

use vector
position y=(0,0)
position b=(0,0)+(14cos45,14sin45)

speed y=(0,10)
speed b=30(cosx,sinx)

locus y=(0,0)+(0,10)t
locus b=(14cos45,14sin45)+30(cosx,sinx)t

0+0t=14cos45+30cosx t & 0+10t=14sin45+30sinx t

t=0.386465
x=211.367

"怎樣知道 BVY 的direction 是S 45 W"
这个相当于x=225，跟我的不相同

huatiang

Probability 和 Discrete Prabability Distributions  有什么不同。
Independent event 到底是什么意思？
请用华语详细解释一下

P(X=x) = (2/5)(3/5)^x for x = 0,1,2,...
0 < (3/5)^x 《 1
0 < (2/5)(3/5)^x 《 1
therefore, 0 < P(X=x) 《 1    for x =0,1,2,3,...
therefore,  0 《 P(X=x) 《 1  Vx E R(意思是for all the value of x is element or real number)
为什么要这样写？
< 和 《 要在什么情况下写？

Allmaths

佳礼卡贴的情况这么多年了还没有改善。。。

puangenlun

Probability 和 Discrete Prabability Distributions  有什么不同。
Probability：概率，某件事发生的可能性
Discrete Prabability Distributions：distribution表示概率发生的一种规律；discrete表示事件发生不是连续的，就好像骰子只可能有123456，不会出现3.1416这样。

Independent event 到底是什么意思？
两件不相关的事。就好比我吃什么早餐与你衣服的颜色是不相关的，彼此不会相互影响。而你起床的时间和去上课所乘坐的交通工具就不是相互独立的。

P(X=x) = (2/5)(3/5)^x for x = 0,1,2,...
0 < (3/5)^x <=1
0 < (2/5)(3/5)^x < 1
therefore, 0 < P(X=x) < 1  for x =0,1,2,3,...
therefore, 0 < P(X=x) < 1  x is any non-negative integer
这个是很直接的推导结果
<和<=完全是按照P(X=x)的公式来写出来的

恩媛

这题呢？？？
The points A and B , distance 120m apart , are situated on the bank of a straight river. It is observed that the position of a point C on the opposite bank is such that angle ABC is 72.25。
and angle ACB is 38.5。Find the width of the river to the nearest meter。。

happy=]

a computer program has an error that causes the program not to function perfectly, n programmer are assigned seperately to detect the error. the probability that each programmer will detect the error is 0.875. determine the value of n if the probability that at least one programmer detects the error is 0.998

c3harry

a computer program has an error that causes the program not to function perfectly, n programmer are  ...
happy=] 发表于 20-3-2012 08:56 PM

                            P(X>= 1) = 0.998                           1-P(X<1) = 0.998
                               P(X=0) = 0.002
n                     0              n
  C       (0.875)  (0.125)     = 0.002
      0
                              0.125^n = 0.002
                                           n= 3