求和1⼀2!+2⼀3!+3⼀4!+……n⼀(n+1)!

2024-11-30 05:52:17
推荐回答(3个)
回答1:

1/2!+2/3!+3/4!+……n/(n+1)!
=(1/1-1/2!)+(1/2!-1/3!)+(1/3!-1/4!)+...+[1/n!-1/(n+1)!]
=1-1/(n+1)!

回答2:

n/(n+1)! =[(n+1)-1]/(n+1)!=1/n! - 1/(n+1)!
1/2!+2/3!+3/4!+……+n/(n+1)!
=(1/1!-1/2!)+(1/2! -1/3!)+……+[1/n! - 1/(n+1)!]
=1/1! -1/(n+1)!
=1-1/(n+1)!

回答3:

与自然对数有关。