(2×4)分之1 + (6×8)分之1 ---+(2006×2008)分之1 +(4×6)分之1 +(8×10)分之1 +---+(2004×2006)分之1=多少
问题描述:
(2×4)分之1 + (6×8)分之1 ---+(2006×2008)分之1 +(4×6)分之1 +(8×10)分之1 +---
+(2004×2006)分之1=多少
答
1/(2×4)+1/(6×8)+...+1/(2006×2008)+1/(4×6)+1/(8×10)+...+1/(2004×2006)=1/(2×4)+1/(4×6)+...+1/(2004×2006)+1/(2006×2008)=(1/2)[(1/2-1/4)+(1/4-1/6)+...+(1/2004)-(1/2006)+(1/2006-1/20...