Question

left side: 0 4 7 8
right side: 4 7 8 9
0 is connected to 4
4 is connected to 4
7 is connected to 9
8 is connected to 7
is this a function?

Answer 1

No, this is not a function. In a function, each element in the left side (domain) should be connected to exactly one element in the right side (range). In this case, 0 is connected to both 4 and 4.