1⼀2⼀(1+1⼀2)+1⼀3⼀(1+1⼀2)*(1+1⼀3)+1⼀4⼀(1+1⼀2)*(1+1⼀

2024-12-26 04:59:16
推荐回答(2个)
回答1:

看看通项
(1/n)/[(1+1/2)(1+1/3)…(1+1/n)]=(1/n)/[(3/2)*(4/3)*…*(n+1)/n]=(1/n)/[(n+1)/2]=2/[n(n+1)]=2[1/n-1/(n+1)]
故,原式=2(1/2-1/3)+2(1/3-1/4)+…+2(1/2005-1/2006)
=2(1/2-1/2006)
=1-1/1003
=1002/1003

回答2:

请帮一个有上进心但成绩较差一点的同学解答