Given:
A ={12, 13, 14, 15, 16, 17}
f : A → Z be defined by f (x) = the highest prime factor of x.
f (12) = the highest prime factor of 12 = 3
f (13) = the highest prime factor of 13 = 13
f (14) = the highest prime factor of 14 = 7
f (15) = the highest prime factor of 15 = 5
f (16) = the highest prime factor of 16 = 2
f (17) = the highest prime factor of 17 = 17
The range of f is the set of all f (x), where .n∈A
Therefore,
range of f = {2, 3, 5, 7, 13, 17}.