Source: Extra Practice
Which of the following statements is always true for a relation R from set A to set B?
Options
Option A
Domain of R = A
Option B
Range of R = B
Option C is correct
Range of R ⊆ Codomain of R
Option D
Codomain of R ⊆ Range of R
Explanation
By definition, the range of a relation is the set of all second elements of the ordered pairs, which is always a subset of the second set B (the Codomain). The domain is not always equal to A (it is a subset), and the range is not always equal to B (it is a subset). Thus, Option 3 is the only universally true statement.