Maths
回答 (2)
2008-10-27 4:44 am
✔ 最佳答案
用等比數列來計算~ 公式等比無限項之和的公式:
S = a/(1-R)
0.206060606060....=0.2+(0.006+0.00006+0.0000006+0.000000006......)
=0.2+ 0.006/(1- 0.01) 首項a=0.006 公比R=0.01
=0.2+ 6/990
=198/990 + 6/990
=204/990
=102/495
2008-10-26 20:45:26 補充：
再化簡= 34/165
2008-10-27 4:43 am
Let 0.20606060... = x
100x = 20.606060...
100x - x = 20.606060... - 0.20606060....
99x = 20.4
x = 20.4/99 = 204/990 = 102/495= 34/165.
100x = 20.606060...
100x - x = 20.606060... - 0.20606060....
99x = 20.4
x = 20.4/99 = 204/990 = 102/495= 34/165.
收錄日期: 2021-04-25 22:35:50
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20081026000051KK02282