a1an11的知识精选

已知数列{an}满足a1=,an+1=.(1)*数列是等差数列,并求{an}的通项公式;(2)若数列{bn}...
问题详情:已知数列{an}满足a1=,an+1=.(1)*数列是等差数列,并求{an}的通项公式;(2)若数列{bn}满足bn=,求数列{bn}的前n项和Sn.【回答】(1)*∵an+1=,=2,是等差数列,+(n-1)×2=2+2n-2=2n,即an=(2)解∵bn=,∴Sn=b1+b2+…+b...
热门标签