己知2^1408/5^605是一個含有605位小數位的小數
求2^1408/5^605的小數位的尾數
求2^1408/5^605的尾數
2013-04-04 11:08 pm
回答 (2)
2013-04-05 6:51 am
✔ 最佳答案
2^1408/5^605= 2^2013/10^605
2013 = 2000 + 13
考慮2^2= 4 (mod 10), 2^4 = 6 (mod 10),
2^8 = 6 (mod 10) => 2^2000 = 6 (mod 10)
2^2013 = 6 * 2^13 = 6 * 2 = 2 (mod 10)
因此2^1408/5^605的小數位的尾數是2
2013-04-04 11:39 pm
2^1408/5^605
=2^803 (2/5)^605
=2^803 (0.4)^605
803/5.....3 ,2^3=8,2^803尾數=8
(0.4)^605尾數=4
2^1408/5^605的小數位的尾數=8x4=2.
2013-04-04 15:40:51 補充：
改正:是803/4....3
=2^803 (2/5)^605
=2^803 (0.4)^605
803/5.....3 ,2^3=8,2^803尾數=8
(0.4)^605尾數=4
2^1408/5^605的小數位的尾數=8x4=2.
2013-04-04 15:40:51 補充：
改正:是803/4....3
收錄日期: 2021-04-27 20:02:51
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20130404000051KK00190