Question

A recursive rule for a geometric sequence is a1=9; an=2/3 (an-1)

Answer 1

Since the first term is 9, then the second is

`\begin{gathered} a_2=9((2)/(3)) \\ a_3=9((2)/(3))^2 \\ \ldots \end{gathered}`

Then, ain iterative rule is

`a_n=9((2)/(3))^(n-1)`

that is, the third one.