考慮等差數列5.5,7,8.5,10,..., 其通項是T(n)
(a)求首n項之和S(n)
我計到S(n)=20
但係個答案係0.75n^2+4.75n
唔知點得出黎
收錄日期: 2021-04-12 01:00:55
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20130922000016KK02390