Answer:
We have set A,
3 ∈ S
n*3 if n ∈ S
Explanation:
A recursion can be defined as a way of defining objects in terms of itself or as parts of itself.
Lets say we a set that is defined as A,
Then the recursive definition of the sets of positive integers with the powers of 3 in A is given as
3 ∈ S
n*3 if n ∈ S
This tells us that 3 is an element of S such that if n is an element of S then in general we would have n*3 to be an element of S