问题很简单!!(高手进)

来源:百度知道 编辑:UC知道 时间:2024/05/10 04:01:19
若n为正整数,试求:1/(n+1)+1/(n+1)(n+2)+1/(n+2)(n+3)+1/(n+3)(n+4)+...+1/(n+99)(n+100)的值.
对的我要追加20分.要过程,没过程的别来.还要写详细点!!!谢谢!!
对不起,我写错了.是1/n(n+1)+1/(n+1)(n+2)+1/(n+2)(n+3)+1/(n+3)(n+4)+...+1/(n+99)(n+100)

用拆项法1/n(n+1)=1/n-1/n+1,然后前后消项
原式=1/n-1/(n+1)+1/(n+1)-1/(n+2)+...+1/(n+99)-1/(n+100)
=1/n-1/(n+100)
=100/n(n+100)

= =

算了 我要去睡觉了 明天还要上课

打字又不快 在此不答``` 当我没回答过``

原式=1/n-1/(n+1)+1/(n+1)-1/(n+2)+1/(n+2)-1/(n+3)+1/(n+3)-1/(n+4)
............+1/(n+99)-1/(n+100)=1/n-1/(n+100)=100/n(n+100)

1/n-1/n+1+1/n+1-1/n+2........+1/n+99-1/n+100=1/n-1/n+100
=99/n(n+100)