1个回答
展开全部
1/2!+2/3!+3/4!+4/5!+……+n/(n+1)!
= (2-1)/2!+(3-1)/3!+(4-1)/4!+(5-1)/5!+……+(n+1-1)/(n+1)!
= (2/2!-1/2!)+(3/3!-1/3!)+(4/4!-1/4!)+(5/5!-1/5!)+……+{(n+1)/(n+1)!-1/(n+1)!}
= (1-1/2!)+(1/2!-1/3!)+(1/3!-1/4!)+(1/4!-1/5!)+……+{1/n!-1/(n+1)!}
= 1 - 1/(n+1)!
= (2-1)/2!+(3-1)/3!+(4-1)/4!+(5-1)/5!+……+(n+1-1)/(n+1)!
= (2/2!-1/2!)+(3/3!-1/3!)+(4/4!-1/4!)+(5/5!-1/5!)+……+{(n+1)/(n+1)!-1/(n+1)!}
= (1-1/2!)+(1/2!-1/3!)+(1/3!-1/4!)+(1/4!-1/5!)+……+{1/n!-1/(n+1)!}
= 1 - 1/(n+1)!
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询