把(1+1/2)看成(1-1/2²)/(1-1/2)则，原式变为(1-1/2²)(1+1/2²)(1+1/2ˆ4)(1+1/2ˆ8)/(1-1/2)+1/2ˆ15等于(1-1/2ˆ16)/(1-1/2)+1/2ˆ15等于1/2-1/2ˆ17+1/2ˆ15等于1/2+3/2ˆ17
