6. Which of the following sets of coordinate pairs is not a relationship where y is a function of X? (1) {(-3,1),(0,5), (2,7), (5,1);
(2) {(-2,4),(-1,0), (1,7),(-2, -- 4)}
(3) {(-3,10), (-2,5), (1,2),(2,5)}
(4) {(4,16), (5,25), (7,49), (10,100)}