1/1*3+1/3*5+1/5*7+……+1/17*19+1/19*21

来源:学生作业帮助网 编辑:六六作业网 时间:2025/01/24 17:36:04
1/1*3+1/3*5+1/5*7+……+1/17*19+1/19*211/1*3+1/3*5+1/5*7+……+1/17*19+1/19*211/1*3+1/3*5+1/5*7+……+1/17*19

1/1*3+1/3*5+1/5*7+……+1/17*19+1/19*21
1/1*3+1/3*5+1/5*7+……+1/17*19+1/19*21

1/1*3+1/3*5+1/5*7+……+1/17*19+1/19*21
1/1*3+1/3*5+1/5*7+……+1/17*19+1/19*21
=(1/1-1/3+1/3-1/5+1/5-1/7+……+1/17-1/19+1/19-1/21)/2
=(1/1-1/21)/2
=10/21