若数列{an}满足a1>0,a2=9,且对任意正整数n都有an+1=a1·an,求数列{an}的通项公式
问题描述:
若数列{an}满足a1>0,a2=9,且对任意正整数n都有an+1=a1·an,求数列{an}的通项公式
答
a2=a1^2 -->a1=3
an+1=3an为等比数列,所以an=3^n