試寫出下列各數列的第 n 項 。
(a) 4, 7, 10,13... (b) 5, 8, 11, 14, ...
(c) 2, 6, 10,14... (d) 10, 17, 24, 31, ....
請幫手
中一數學問題
2006-10-18 4:27 am
回答 (2)
2006-10-18 4:42 am
✔ 最佳答案
(a) 3n - 2(b) 2 + 3n
(c) 4n - 2
(d) 7n+ 3
2006-10-18 22:19:35 補充：
(a) 3n 1(a) 4 = 3 1 7 = 6 1N = 3n 1(b) 5 = 2 3 8 = 2 6N = 2 3n(c) 2 = 4 - 2 6 = 8 - 2N = 4n - 2(d) 10 = 7 3 17 = 14 3N = 7n 3
參考: me
2006-10-18 5:45 am
a) 4 + (n -1) 3 c) 2+ (n -1) 4
= 4 + 3n -3 = 2 + 4n - 4
= 3n -1 = -2 +4n
= 4n -2
b) 5 +(n -1 ) 3 d) 10+ (n- 1) 7
= 5+ 3n - 3 = 10+7n -7
= 2 +3n = 3+ 7n
= 4 + 3n -3 = 2 + 4n - 4
= 3n -1 = -2 +4n
= 4n -2
b) 5 +(n -1 ) 3 d) 10+ (n- 1) 7
= 5+ 3n - 3 = 10+7n -7
= 2 +3n = 3+ 7n
收錄日期: 2021-04-12 15:43:20
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https://hk.answers.yahoo.com/question/index?qid=20061017000051KK03843