Function, Domain and Range

Question

Suppose x=1,2,5 and f(1)=2, f(2)=4, and f(5)=6

 

1. Is f defined in such a way a function?

 

2. If it is, what is the domain and range of f?

Answer 1

1.  sure it's a function; there is exactly one output for any given input.

2. domain: {1,2,5}

    range:   {2,4,6}