数学题目如何简算?

来源:百度知道 编辑:UC知道 时间:2024/07/02 15:09:06
(1+1/2)*(1-1/2)*(1+1/3)*(1-1/3)*...(1+1/2006)*(1-1/2006)怎么简算呀?

=3/2*1/2*4/3*2/3......2007/2006*2005/2006

=1/2*2007/2006

=2007/4012

(1+1/2)*(1-1/2)*(1+1/3)*(1-1/3)*...(1+1/2006)*(1-1/2006)

=(1+1/2)(1+1/3)...(1+1/2006)(1-1/2)(1-1/3)...(1-1/2006)

=3/2*4/3...2007/2006*1/2*2/3...2005/2006

=1/2*2007*1/2006

=2007/4012

[1+1/2][1-1/2][1+1/3][1-1/3]*...[1+1/2006][1-2006]
=3/2*1/2*4/3*2/3*...*2007/2006*2005/2006
=(2007/2)*(1/2006)
=2007/4012

原式=3/2*1/2*4/3*2/3*...*2007/2006*2005/2006=(中间好多分母分子可以约去)1/2*2007/2006=2007/5002.

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