Function vs not function

1. To be a function or not to be
a function

2. Function Not a Function
126
105
84
63
42
21
YX
105
44
83
51
42
21
YX

3. Function Not a Function
842086Y
-10830-3X
842086Y
-87-20-2X

4. Function Not a Function
(4,12)
(5,15)
(6,18)
(7,21)
(8,24)
(4,12)
(4,15)
(5,18)
(5,21)
(6,24)

5. Function Not a Function
10
3
4
7
5
2
3
4
8
10
3
5
7
2
2
3
4
7
5

6. Function Not a Function
-3
-2
-1
0
1
-6
-1
-0
3
15
-3
-2
-1
0
1
-6
-1
-0
3
15

7. Function Not a Function

8. Function Not a Function

9. Function Not a Function