数学Paper 1讨论专区

Lov瑜瑜4ever

if a and b are not real number, then ab is also not a real number.
State whether the statement abov ...
數學神童 发表于 17-5-2010 03:59 PM

the above statement is false
example: Let a=i=(-1)^1/2 and b=2i=2(-1)^1/2
              hence ab=2i^2=2[(-1)^1/2]^2=2(-1)=-2
              and "-2" is a real number...

sim91

我不太会这几题..找到的答案都不一样
1.A man saves RM200 at the beginning of each year and receives an interest of 8% each year.What is the total amount of savings together with the interest after 15 years?(ans:RM 5865)
2.A company borrows RM25000 from a bank which charges an interest of 5% per year on the loan.Repayment is done by installments which are RM2000 each year and the first payment is made the year after the loan was taken.Find the balance which is unpaid after 15 years.(ans:RM8816)
3.A trader borrows RM5000 from a bank.The loan is repaid by 18 equal yearly installments,the first payment being made the year after the loan is taken.If the interest charged on the loan is 8% each year,find the amount to be paid each year.(ans:RM533.5)
4.A teacher borrows RM90000 from the government to buy a house.The interest charged on the loan is 4% a year and is calculated based on the balance outstanding each year.He is required to repay the loan by monthly installments for a period of 20 years.If the interest charged is not changed,find the amount to be paid each month.(RM 552)

walrein_lim88

我不太会这几题..找到的答案都不一样
1.A man saves RM200 at the beginning of each year and recei ...
sim91 发表于 20-5-2010 06:14 PM

qwer0909

想问大家一些问题，我是刚进form6的～
1) draw the interval on number line=> (-2,0)U(3,6)
2)find the mean, mode, n median
mass of peas=30-39, 40-49, 50-69, 70-89, 90-119
  frequency=     16       26       36        24      18

qwer0909

想问大家一些问题，我是刚进form6的～
1) draw the interval on number line=> (-2,0)U(3,6)
2)find the mean, mode, n median
mass of peas=30-39, 40-49, 50-69, 70-89, 90-119
  frequency=     16       26       36        24      18

walrein_lim88

想问大家一些问题，我是刚进form6的～
1) draw the interval on number line=> (-2,0)U(3,6)
2)find the  ...
qwer0909 发表于 20-5-2010 09:37 PM

   1. ( -2 , 0 ) 代表 -2 <x <0
     U 代表 union/OR
    (3 , 6 ) 代表 3<x<6
  如果 [   ],  代表  A <= x <= B
2. 用FORMULA就可以了。。去看下课本paper 2 的FORMULA

qwer0909

1. ( -2 , 0 ) 代表 -2
walrein_lim88 发表于 20-5-2010 09:41 PM

第二题不一样啊，它的class interval不一样的～

qwer0909

1. ( -2 , 0 ) 代表 -2
walrein_lim88 发表于 20-5-2010 09:41 PM

第一题我知道是-2 <x <0和3<x<6，但是我画在numberline的时候是画在同一条线上呢还是分开画呢？谢谢^^

walrein_lim88

第二题不一样啊，它的class interval不一样的～
qwer0909 发表于 20-5-2010 09:43 PM

   
   其实没分别的。。做法一样。。MEAN一样，你自己试试看

walrein_lim88

第一题我知道是-2
qwer0909 发表于 20-5-2010 09:44 PM

    同一个DIAGRAM。。。。只是中间0 到 3 没有线

qwer0909

其实没分别的。。做法一样。。MEAN一样，你自己试试看
walrein_lim88 发表于 20-5-2010 09:53 PM

不好意思，想问一下，为何你的median的lower boudary是拿39.5的呢？不是要拿median class的lower boundary 吗？

walrein_lim88

不好意思，想问一下，为何你的median的lower boudary是拿39.5的呢？不是要拿median class的lower boundar ...
qwer0909 发表于 20-5-2010 10:00 PM

    对不起。。算错了！！！粗心～～～

qwer0909

对不起。。算错了！！！粗心～～～
walrein_lim88 发表于 20-5-2010 10:03 PM

嘻嘻，没关系，谢谢你哦～功课终于做完了，好怕以后的数学会很难哦～

qwer0909

又有新问题了，不好意思啊，我的数学很差的～
the nine numbers 5,6,13,5,10, 13, 3, x and y has a mean 8 and a mode of 5.Find the possible values of x and y and the median of 9 numbers~
这题好难哦～～

Log

回复 1074# qwer0909
   3,5,5,6,10,13,13,x,y
since mode is 5,so, from above we can clearly see that x or y may be 5.
assume x is 5, then given  mean = 8
                                      (3+5+5+6+10+13+13+x+y)/9 = 8
                                             55+x+y=72
                                   (∵x=5)       y=12
similarly, if we assume y=5,x=12
∴x=5,y=12 or x=12,y=5
for median,  put the x and y values back to the set and arrange them in ascending order
3,5,5,5,6,10,12,13,13     
∴ median=6

Log

心血来潮，出了这题 try
find  ∫ 【(cos θ+sin θ)(1-cos θ)(cos θ-sin θ)】/【cot 2θ √(2cos&#179;θ+3sin&#178;θ)】dθ

Log

心血来潮，出了这题 try
find  ∫ 【(cos θ+sin θ)(1-cos θ)(cos θ-sin θ)】/【cot 2θ √(2cos&#179;θ+3sin&#178;θ)】dθ

ELFofWAR

我不是很明白argument是怎样变得
谁可以解释一下吗？

walrein_lim88

卡帖！！！！！

walrein_lim88

又卡帖！！！！！！