Let A = [9, 10, 11, 12, 13]

Given:

A ={9, 10, 11, 12, 13}

f : A → N  be defined by f (n) = the highest prime factor of n.

f (9) = the highest prime factor of 9 = 3

f (10) = the highest prime factor of 10 = 5

f (11) = the highest prime factor of 11 = 11

f (12) = the highest prime factor of 12 = 3

f (13) = the highest prime factor of 13 = 13

The range of $f$ is the set of all $f(n)$, where $n \in A$.

Therefore,

range  of  f  = {3, 5, 11, 13}