中一數學考試問題(20點!!)急

A.Typical sequence

1.sequence of square number
e.g.1 , 4(2x2) , 9(3x3) ,16(4x4) ,25(5x5)................

2.sequence of triangular number
e.g.1 ,3 (=1+2) ,6 (=3+3) ,10 (=6+4)..........................

3.Fibonacci sequence
e.g.1 ,1 ,2 ,3 ,5 (2+3) ,8 ,13 ,21(8+13)............

4.Arithmetic sequence(AS)
e.g.1 ,4(=1+3),7(=4+3),10(=7+3)
e.g.19 ,12(-7) ,5(-7) ,-2(-7)..........

5.Geometric sequence(GS)
e.g.2 ,6(=2x3) ,18(=6x3) ,54(=18x3).............
e.g.729 ,243(=729x3分之一) ,81(=243x3分之一) ,27(=81x3分之一).........


B.General term
e.g. consider 1 ,4 ,9 ,16 ,25 ,36.........
Write as 1x1(1st term) ,2x2(2nd term), 3x3(3rd term) ,4x4 ,5x5 ,6x6....nxn(nth term)
Find the 12th term of the above sequence (☆Put n=12 into the general)
If n=12
12th term=12x12
=144
e.g.general term:nxn+2n ,find the 6th term and 7th term
the 6th term =6x6+2x6=48
the 7th term =7x7+2x7=63
☆☆☆e.g.Find the general term of sequence 3 ,6 ,9 ,12 ......
1st term= 3= 3x1
2nd term= 6= 3x2
3rd term= 9= 3x3
4th term= 12= 3x4
nth term= 3xn
留意☆:1st term=3x1
2nd term=3x2
3rd term=3x3
nth term=3n
每行第一個字和最後一個字是一樣
1st term=ax1
2nd term=ax2


end..
@@我做了一個小時QAQ

2014-01-09 20:23:28 補充：
其實我下星期也考Math....

Fibonacci sequence 是之前兩項十埋等如第三項, 1,2,3,5,8,13,21等等!
Arithmetic sequence 是數學級數, 2,4,6,8,10 我問你等差是什麼?
Geometric sequence是幾何級數, 1,3,9,27,81 我問你等比是什麼?

其實n represent咩?
n 應該represent number
(by myself ' ...

2014-01-09 22:29:25 補充：
如何去推敲出一條general term?
好似3, 5/4, 7/9, 9/16, 11/25,
要反推 要試出來..

因為你見到有整數 有分數 所以個general term 會係有分數

T(1) = 3 = 3/(1^2)
T(2) 5/4 = 5/(2^2)
單睇呢度 就會知個分母係n^2
但個分子要試
3 可以 = 2 + 1 姐係 2+n
但係5 就吾等於 2 + 2 所以2+n 吾適用
但我地睇5 可以 變 4+1 >>(2)2 +1
7>> 6+1 >>(3)2 +1
所以可以代入為2n+1
分子分母合埋一起就係
2n+1 / (n^2)

你自己本書D內容才最接近你的需要，所以叫做「溫書」，快D溫書，睇例題同做練習啦！有問題就問，貓老師好鬼好人又好鬼「有料」，一定幫你答。

我無挽電腦呀._.
我係唔明無方向先上黎發問架炸TvT
同埋我琴晚2點幾先訓..我驚如果咁晚早訓我訓吾着!!
anyway,thx ur comment

2014-01-09 17:40:27 補充：
其實唧係點..我完全吾明呢課講乜野..
原諒我是1個蠢人-_-xd

-

2014-01-09 17:53:59 補充：
其實n represent咩?
點諗個general term出黎??

2014-01-09 18:03:28 補充：
如何去推敲出一條general term?
咁遇到d複雜do既題好似你岩岩3, 5/4, 7/9, 9/16, 11/25,
應該點樣去諗or用咩方法??

2014-01-13 13:56:21 補充：
多謝各位大大回應:)
thank a lot！！
咁次都ｏｋ　ｏ既　應該吾洗肥：Ｄ

你睇下Ｄ舊post，應該有Ｄ有用的題目畀你參考。

不過我建議你唔好玩電腦，快Ｄ去睇番之前Ｄ功課，測驗，自己做多次～

睇下書的例題～

咁更加有用～

考試前要早Ｄ瞓～

2014-01-09 17:26:14 補充：
1, 2, 3, 4, 5, 6, ...
general term = n

2, 4, 6, 8, 10, ...
general term = 2n

1, 3, 5, 7, 9, ...
general term = 2n-1

3, 5, 7, 9, 11, ...
general term = 2n+1

1, 4, 9, 16, 25, ...
general term = n²

2014-01-09 17:49:58 補充：
以上為常見情況～
但可以考你組合：

3, 5/4, 7/9, 9/16, 11/25, ...
general term = (2n+1)/n²

2014-01-09 17:50:35 補充：
即係你代 n = 1，會計出第一個term
代 n = 2，會計出第二個term
如此類推～

2014-01-09 23:24:49 補充：
pangju 講得好好～

但而家夜啦～

佢應該要去瞓覺，準備聽日考試～

2014-01-13 18:37:28 補充：
好啦～

繼續努力～～～～！！