亲,您看懂了没?加上一个1/128,再减去一个1/128是用来做辅助用的,这样后面就是2/128,变成了两个1/64,最后一直收到两个1/2后等于1-1+1/128=1/128
1-1/2-1/4-1/8-1/16-1/32-1/64-1/128
=1-(1/2+1/4+1/8+1/16+1/32+1/64+1/128)
=1-(1/2+1/4+1/8+1/16+1/32+1/64+1/128)-1/128+1/128
=1-(1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/128)+1/128
=1-(1/2+1/4+1/8+1/16+1/32+1/64+1/64)+1/128
=--------(类推)
=1-1+1/128
=1/128
原式
写得丑,别见怪!不懂可追问