举报
原原恋雨
如何参考答案是这个的话 那么原题应该是“数列求和1/2!+2/3!+3/4!+...+n/(n+1)!=" 下面是新题的具体做法: 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!+...+(n+1)/(n+1)!-1/(n+1)! =1/2!+2/3!+3/4!+...+(n-1)/n!+1/n!-1/(n+1)! =1/2!+2/3!+3/4!+...+n/(n)!-1/(n+1)! =…… =1/2!+1/2!-1/(n+1)! =1-1/(n+1)!