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1/2!+2/3!+3/4!+.+n/(n+1)!求和

来源:学生作业帮 编辑:作业帮 分类:综合作业 时间:2024/05/16 17:57:39
1/2!+2/3!+3/4!+.+n/(n+1)!求和
1/2!+2/3!+3/4!+.+n/(n+1)!
=1/2!+2/3!+3/4!+.+n/(n+1)!+1/(n+1)!-1/(n+1)!
=1/2!+2/3!+3/4!+.+1/n!-1/(n+1)!
=1-1/(n+1)!
再问: 详细点,我看不懂1/2!+2/3!+3/4!+.....+1/n!=1不懂
再答: 1/2!+2/3!+3/4!+.....+(n-1)/n!+n/(n+1)! =1/2!+2/3!+3/4!+.....+(n-1)/n!+n/(n+1)!+1/(n+1)!-1/(n+1)! =1/2!+2/3!+3/4!+.....+(n-1)/n!+(n+1)/(n+1)!-1/(n+1)! =1/2!+2/3!+3/4!+.....+(n-1)/n!+1/n!-1/(n+1)! =1-1/(n+1)! 从后往前消项,明白了吧
再问: 明白