S=(1+2^-1/32)(1+2^-1/16)(1+2^-1/8)(1+2^-1/4)(1+2^-1/2) 两边同乘以 (1--2^-1/32): (1-2^-1/32)S=(1-2^-1/32)(1+2^-1/32)(1+2^-1/16)(1+2^-1/8)(1+2^-1/4)(1+2^-1/2) =(1-2^-1/16)(1+2^-1/16)(1+2^-1/8)(1+2^-1/4)(1+2^-1/2) =(1-2^-1/8)(1+2^-1/8)(1+2^-1/4)(1+2^-1/2) =(1-2^-1/4)(1+2^-1/4)(1+2^-1/2) =(1-2^-1/2)(1+2^--1/2) =1-2^-1=1-1/2=1/2, 则S=1/2(1-2^-1/32).