写出等比数列8/3,4,6,9,···的通项公式,并写出它的第5项到第8项
问题描述:
写出等比数列8/3,4,6,9,···的通项公式,并写出它的第5项到第8项
答
a1=8/3a2=4 =a1*(3/2)a3=6 =a2*(3/2)=a1*(3/2)*(3/2)a4=9 =a3*(3/2)=a1*(3/2)*(3/2)*(3/2)an=a1*(3/2)^(n-1)a5=8/3*(3/2)^4=27/2a8=8/3*(3/2)^7=(3^6)/(2^4)