答:利用平方差公式
(1-1/2)X(1+1/2)X(1-1/3)X(1+1/3)X(1-1/4)X(1+1/4)
=[1-(1/2)^2]*[1-(1/3)^2]*[1-(1/4)^2]
=(1-1/4)(1-1/9)(1-1/16)
=(3/4)(8/9)(15/16)
=5/8
(1-1/2)X(1+1/2)X(1-1/3)X(1+1/3)X(1-1/4)X(1+1/4)
=[(1-1/2)X(1+1/2)]×[(1-1/3)X(1+1/3)]×[(1-1/4)X(1+1/4) ]
=﹙1-¼)×﹙1-1/9)×﹙1-1/16﹚
=3/4×8/9×15/16
=5/8
(1-1/2)X(1+1/2)X(1-1/3)X(1+1/3)X(1-1/4)X(1+1/4)=(1-1/4)(1-1/9)(1-1/16)=3/4*8/9*15/16=5/8
利用平方差公式(x+1)(x-1)=x²-1