Question

what is the domain of this relation?
(1, 7)
(-7, 1)
(-7, -4)
(3, -5)
{-7, -5, 1, 3} {-5, -4, 1, 7}
{-5, 1, 3, 7} {-7, 1, 3}

Explanation:

Step1: Recall domain definition

The domain of a relation (set of ordered pairs) is the set of all first elements (x - values) of the ordered pairs.

Step2: Identify first elements

Given ordered pairs: \((1, 7)\), \((-7, 1)\), \((-7, -4)\), \((3, -5)\)
First elements (x - values) are: \(1\), \(-7\), \(-7\), \(3\)

Step3: Form domain set

Remove duplicates. The distinct first elements are \(-7\), \(1\), \(3\) (note that \(-7\) appears twice, but we only include it once in the domain set). So the domain is \(\{-7, 1, 3\}\)

Answer:

\(\{-7, 1, 3\}\) (corresponding to the option: \(\{-7, 1, 3\}\))