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1/(1×3×5)+1/(3×5×7)+1/(5×7×9)+1/(7×9×11)+...+1/(2001×2003×20

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/09/14 14:52:27
1/(1×3×5)+1/(3×5×7)+1/(5×7×9)+1/(7×9×11)+...+1/(2001×2003×2005)=?
1/(1×3×5)+1/(3×5×7)+1/(5×7×9)+1/(7×9×11)+...+1/(2001×2003×2005)
=1/4*(1/1*3-1/3*5)+1/4(1/3*5-1/5*7)+...+1/4(1/2001*2003-1/2003*2005)
=1/4(1/1*3-1/3*5+1/3*5-1/5*7+...+1/2001*2003-1/2003*2005)
=1/4(1/1*3-1/2003*2005)
=1/12-1/(2003*8020)