设数列{an}的前n和为Sn,且an+Sn=1(n属于正自然数).(1)求{an}的通项公式(2)若数列{bn}满足b1...
问题描述:
设数列{an}的前n和为Sn,且an+Sn=1(n属于正自然数).(1)求{an}的通项公式(2)若数列{bn}满足b1...
设数列{an}的前n和为Sn,且an+Sn=1(n属于正自然数).(1)求{an}的通项公式(2)若数列{bn}满足b1=1且b(n-
答
n=1
a1+a1=1 =>a1=1/2
Sn=1-an
=>an=Sn-S(n-1)=a(n-1)-an
=>an=0.5a(n-1)
=>an=0.n (即0.5的N次方)