hi, can someone pls help me? I really don’t understand this

Answer: 1 is not, 2 is, 3 is, 4 is, 5 is, 6 is not
Step-by-step explanation:
1 is not because 2 has two arrows coming off of it and each input can only have one output. 6 is not because if you draw a line down the graph it will hit the figure more than once( this is called the pencil drop test)
Function is an assignation that for each element of first set assigns one and only one element from second set.
1) NO {element 2 from set one has assigned two elements (b, c) from set two}
2) YES
3) YES {several elements from set one can have assigned the same element from set two}
4), 5) YES
6) NO {for x from about -4 to about 0.5 there are two y}