Determine whether each relation represents a function. For each function, state the domain and range.

1) {(2,6), (-3,6), (4,9), (1,10)}
2) {(1,3), (2,3), (3,3), (4,3)}
3) {(-2,4), (-2,6), (0,3), (3,7)}
4) {(-2,4), (-1,1), (0,0), (1,1)}