Step-by-step explanation:
1. Not a function There is no correlation plus there is two y values for the same x.
2.Not a function, There is two y values for the same x
3.Yes, you can draw a linear line through the points to represent the equation, also there is one x for one y.
4.Yes, this is a step function. It seems there are two y values for same x. but the shaded circle means to include it and the open circle means dont include it so it is a function.
5.No, this is a parabola but this function has two y values for the same x
6. Yes, this is a absolute value function and there is multiple x values for the same y so it IS a function