1+2+3+...+n = [n(n+1)] /2
呢個formula 叫咩?
同埋係咪 mathematical concept?
1+2+3+...+n = [n(n+1)]/2 *呢個formula叫咩? (10點!!)
2007-10-20 12:53 am
回答 (2)
收錄日期: 2021-04-16 16:59:45
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https://hk.answers.yahoo.com/question/index?qid=20071019000051KK03044