(1-1/4)*(1-1/9)*(1-1/16).....(1-1/100)的简便算法

如题所述

第1个回答  2007-09-20
(1+1/2)(1-1/2)(1+1/3)(1-1/3)(1+1/4)(1-1/4).....(1+1/10)(1-1/10)
=(3/2)(1/2)(4/3)(2/3)(5/4)(3/4)......(11/10)(9/10)
=(3/2)(4/3)(5/4)...(11/10)*(1/2)(2/3)(3/4)...(9/10)
=(11/2)*(1/10)
=11/20本回答被提问者采纳
第2个回答  2007-09-20
每一项拆为俩项的乘积,如1-1/4拆为(3/2)x1/2
第3个回答  2007-09-20
=3/4*8/9*15/16*24/25*35/36*48/49*63/64*80/81*99/100
=11/20