小明为了求1/2+1/4+1/8+1/16+1/32+...+1/2^n的值为( )
1/2+1/4+1/8+1/16+1/32+...+1/2^n
=1/2+1/4+1/8+1/16+1/32+...+1/256+1/256- 1/2^n
=1/2+1/4+1/8+1/16+1/32+...+1/128+1/128- 1/2^n
=1/2+1/4+1/8+1/16+1/32+1/64+1/64-1/2^n
=1/2+1/4+1/8+1/16+1/32+1/32........-1/2^n
=……
=1-1/2^n
=2^n分之( 2^n-1 )
追问在设计一个能求1/2+1/4+1/8+1/16+1/32+...+1/2^n的值的几何图形