國二數列問題 求算式?
回答 (3)
2019-03-08 11:13 pm
✔ 最佳答案
設此數列之總和為S50則S50=nx(a1+a50)/2=50x50/2=1250
2019-03-10 3:37 pm
等差數列的總合
=總項數×(首項+末項)/2
=50×(a1+a5)/2
=50×50/2
=50×25
=1250
=總項數×(首項+末項)/2
=50×(a1+a5)/2
=50×50/2
=50×25
=1250
2019-03-09 7:52 am
2500
收錄日期: 2021-04-18 18:13:31
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20190308144701AAbKzRs