Question

Mapping diagram: Is it a function? (yes / no ) Why or why not?

Answer 1

It is a function

Why? Because each input maps to exactly one output. The input oval represents the domain (set of all possible inputs). The output oval is the range, which is the set of all possible outputs. If we had something like the input 0 mapping to the outputs 2 and 4 at the same time, then we wouldn't have a function.