1/1×3+1/3×5+1/5×7+……+1/2003×2005

来源:百度知道 编辑:UC知道 时间:2024/05/25 05:08:42

解:原式=(1/1-1/3+1/3-1/5+1/5-1/7+……+1/2003-1/2005)×1/2
=(1-1/2005)×1/2
=2004/2005×1/2
=1002/2005

解:原式=1/2(1-1/3)+1/2(1/3 -1/5)+...+1/2(1/2003 -1/2005)
=1/2[(1/1-1/3)+(1/3-1/5)+...(1/2003-1/2005)
=1/2(1-1/2005)
=1002/2005

注意满足:1/n(n+2)=1/2(1/n -1/n+2)

原式=1/2[(1/1-1/3)+(1/3-1/5)+...(1/2003-1/2005)
=1/2(1-1/2005)
=1002/2005