Math F.1

(-1)^(n+1) for n=1,2,....
or
(-1)^n for n = 0,1,2,...

The general tern is...... -1既n次方:

n
-1

The general term is (-1)^(n+1)

when n=1
(-1)^(1+1) = (-1)^2 = 1

when n=2
(-1)^(2+1) = (-1)^3 = -1

when n=3
(-1)^(3+1) = (-1)^4 = 1

and so on

1.-1.1.-1.1.-1....
第6頂:(n=6)=(-1)的6次方＝
（－１）ｘ（－１）ｘ（－１）ｘ（－１）ｘ（－１）ｘ（－１）＝＋１＝１
第7頂:(n=7)=(-1)的７次方＝
（－１）ｘ（－１）ｘ（－１）ｘ（－１）ｘ（－１）ｘ（－１）ｘ（－１）＝－１
通頂=(-1)的n次方

2006-10-19 21:46:55 補充：
ｓｏｒｒｙ！！是第６項．第７項和通項！！ｓｏｒｒｙ！！！