一道计算题,求高手帮忙!1/2+1/4+1/8+1/16+1/128+1/256+…+1/2^n

问题描述:

一道计算题,求高手帮忙!1/2+1/4+1/8+1/16+1/128+1/256+…+1/2^n
计算:1/2+1/4+1/8+1/16+1/128+1/256+…+1/2^n
急!

x=1/2+1/4+1/8+1/16+1/128+1/256+…+1/2^n
2x=1+1/2+1/4+1/8+1/16+1/128+1/256+…+1/2^n-1
两式相减,x=1-1/2^n