Question

State the domain and range for the following relation. Then determine whether the relation represents a function. {(6,2), (-5,2) (9,7), (6,12)}

Answer 1

Well... it DOES NOT pass the straight line test. To be a function there can only be ONE y value for each x value. But clearly y is both 2 and 12 when x = 6.
But it is only 4 dots...
So.. .the domain starts at -5 and only goes to 9, that is
domain = {x| x = -5,6, 9}
Now you find the range

Answer 2

Express the relation {(-2, 1), (-1,0), (1,2), (2, 3), (3, 4)} as a table and as a mapping. Then, state the domain and range of the relation.