n/(n+1)!数列求和1/2!+2/3!+3/4!+…+n/(n+1)!
问题描述:
n/(n+1)!数列求和
1/2!+2/3!+3/4!+…+n/(n+1)!
答
因为 n/(n+1)!=(n+1-1)/(n+1)!=(n+1)/(n+1)!-1/(n+1)!=1/n!-1/(n+1)!.
所以 ...原式=1/1!-1/2!+1/2!-1/3!.+1/n!-1/(n+1)!=1-1/(n+1)!
应该是对的