Answer:
5. not a function
6. function
7. not a function
8 function
9. not a function
10 function
Explanation:
5. this fails the vertical line test. Since a vertical line would touch more than one point this is not a function
6. this is a function. Each input (or x) has only one output, so it is a function
7. This is not a function . X=2 goes to more than one y value x =2 goes to y=5 and y=6. so it is a relation not a function
8. this passes the vertical line test. Since a vertical line does not touch more than one point this is a function
9. This is not a function . X=5 goes to more than one y value x =5 goes to y=-4 and y=1. so it is a relation not a function
10. this is a function. Each input (or x) has only one output, so it is a function