Domain

Definition of Domain

Domain of a relation is the set of all x-coordinates of the ordered pairs of that relation.

Examples of Domain

    Domain of the relation {(3,4), (9,8), (4,5)} is {3, 4, 9}.

Video Examples: How to Figure the Domain & Range of Ordered Pairs : Math Tips


Solved Example on Domain

Ques: Find the domain of f(x) = (x + 3)-1.

    Choices:
    A. (- 8, - 3) or (- 3, - 8)
    B. (- 3, 3)
    C. (- 8, - 3) or (3, 8)
    D. (- 8, 8)
    Correct Answer: A

Solution:

    Step 1:f(x) = (x + 3)-1.
    Step 2:  example of  Domain
    Step 3: Domain of a function is the set of all possible input values for the function.
    Step 4: Observe that the function  example of  Domain is not defined only when x = - 3.
    Step 5: So, the domain for this function is (- 8, - 3) or (- 3, - 8).