Domain and Range & Function

Question

(1,9) (-4,-8) (8, -3) (7,-2) (5, -5) (-4, 12)

 

State the domain and range of the following relation and determine if it is a fuction, explain why.

 

 

Answer 1

If any ordered pair 'reuses' the same x value as another ordered pair, but has a different y value, this violates the Vertical Line Test (of the graph of the relation). This problem is only a relation, not a function (check what happens if x = -4).

 

The domain is the set of all the x values (don't list any duplicates);

the range is the set of all the y values (exclude listing any duplicates).