(1-1/1006^2)(1-1/1007^2)(1-1/1008^2)……(1-1/2011^2)怎么做?
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(1-1/1006^2)(1-1/1007^2)(1-1/1008^2)……(1-1/2011^2)怎么做?
(1-1/1006^2)(1-1/1007^2)(1-1/1008^2)……(1-1/2011^2)怎么做?
(1-1/1006^2)(1-1/1007^2)(1-1/1008^2)……(1-1/2011^2)怎么做?
=(1-1/1006)(1+1/1006)(1-1/1007)(1+1/1007)(1-1/1008)(1+1/1008)……(1-1/2011)(1+1/2011)
=1005/1006 × 1007/1006×1006/1007 × 1008/1007×1007/1008 × …… ×2011/2010×2010/2011 ×2012/2011
=1005/1006 ×2012/2011
=2010/2011
等于2010/2011
=(1-1/1006)(1+1/1006)(1-1/1007)(1+1/1007)(1-1/1008)(1+1/1008)……(1-1/2011)(1+1/2011)
=1005/1006 × 1007/1006×1006/1007 × 1008/1007×1007/1008 × …… ×2011/2010×2010/2011 ×2012/2011
=1005/1006 ×201...
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=(1-1/1006)(1+1/1006)(1-1/1007)(1+1/1007)(1-1/1008)(1+1/1008)……(1-1/2011)(1+1/2011)
=1005/1006 × 1007/1006×1006/1007 × 1008/1007×1007/1008 × …… ×2011/2010×2010/2011 ×2012/2011
=1005/1006 ×2012/2011
=2010/2011
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