1/1×2+1/2×3+……1/2004×2005=( 的答案?急急急急急急急急!!!!!!!!!!!!!
来源:百度知道 编辑:UC知道 时间:2024/06/04 08:04:03
那位赶紧给我答案,快的话追加分,急急啊啊!!!!
注意:1/[n(n+1)]=1/n-1/(n+1)
套用这个公式
1/1×2+1/2×3+……1/2004×2005
=1-1/2+1/2-1/3+......+1/2004-1/2005
=1-1/2005
=2004/2005
1/1×2+1/2×3+……1/2004×2005
=1/1-1/2+1/2-1/3+1/3-1/4+……+1/2004-1/2005
=1/1-1/2005
=2004/2005
1/1×2+1/2×3+……1/2004×2005
=1/1-1/2+1/2-1/3+1/4-……-1/2004+1/2004-1/2005
=1-1/2005
=2004/2005
原式=1-1/2+1/2-1/3+1/3-1/4+……+1/2003-1/2004+1/2004-1/2005
=1-1/2005
=2004/2005
2004/2005
上面的没看清题目
人家只要答案,没要过程
原式=1-1/2+1/2-1/3.......+1/2004-1/2005=2004/2005
1+1/(1+2)+1/(1+2+3)+...+1/(1+2+3+...+100)
1+1/(1+2)+1/(1+2+3)+-------+1/(1+2+3+----+100)
1+1/1+2+1/1+2+3+...+1/1+2+3...+2000
1*(1/1+2)*(1/1+2+3)*~~~*(1/1+2+~~~2005)=?
1+1/2+1/3+.....+1/n
1+1/2+1/3+...+1/100
1-1/2+1/3-.....-1/10
(1+1/2+1/3+1/4)×
3/2=2+1/1*2=1/1+1/2
(1/2005-1)(1/2004-1)........(1/3-1)(1/2-1)