(1-1/2*1/2)*(1-1/3*1/3)*......*(1-1/2007*1/2007)*(1-1/2008*1/2008)=?

来源:百度知道 编辑:UC知道 时间:2024/07/01 07:40:07

1-(1/n^2)=(n^2-1)/n^2=(n-1)(n+1)/n^2=[(n-1)/n][(n+1)/n]
原式=[(1/2)*(3/2)][(2/3)*(4/3)]*……[(2007/2008)*(2009/2008)]
=(1/2)*(2009/2008)
=2009/4016

(1-1/2*1/2)*(1-1/3*1/3)*......*(1-1/2007*1/2007)*(1-1/2008*1/2008)
=(1-1/2)(1+1/2)(1-1/3)(1+1/3)...(1-1/2007)(1+1/2007)(1-1/2008)(1+1/2008)
=1/2*3/2*2/3*4/3*...*2006/2007*2008/2007*2007/2008*2009/2008
=1/2*2009/2008
=2009/4016