求极限:lim(1+1/2+1/4+……+1/2的n-1次方)

问题描述:

求极限:lim(1+1/2+1/4+……+1/2的n-1次方)

原式=lim(1-1/2^n)/(1-1/2)
=lim(2-1/2^(n-1))
=2