求Sigma算法！！！?
回答 (1)
2017-06-22 8:00 pm
Sol
Σ(k=50 to 100)_k^2
=Σ(k=1 to 100)_k^2－Σ(k=1 to 49)_k^2
=100*101*201/6－49*50*99/6
=338350－247450
=90900
Σ(k=50 to 100)_k^2
=Σ(k=1 to 100)_k^2－Σ(k=1 to 49)_k^2
=100*101*201/6－49*50*99/6
=338350－247450
=90900
收錄日期: 2021-04-30 22:26:36
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20170618100625AAZ56my