the coordinates indicate it is not a function but the inverse may be. For every point, reverse x and y. if you have 2 xs which are the same but 2 different y values then inverse isn't a function
suppose original function is (x1,y1) (x2,y1)
Switch for inverse (y1,x1) (y1,x2)
then inverse would NOT BE a function because same y1 produces x1, x2 -impossible
