1.Which set of points does not represent a function?
1) {(-3,-2).(-1,-2),(0,-1),(1,0))
2) {(-2,3), (0,4),(3,-2),(4,2)}
3) {(2,-2), (1,4),(2,5),(3,6)}
4) ((-2,4),(1,1),(2,4),(3,9)}