Use the domain and range of each of the following relations to determine which is a function.
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Answer:
Option A is correct.
{(3, -3), (9, -6) ,(0, -9)}
Step-by-step explanation:
A function is a relation in which every element of the domain is paired with exactly one element of the range.
(a)
{(3, -3), (9, -6) ,(0, -9)}
Domain is all the x-values, and range is all the y-values.
Domain: {3, 9, 0}
Range: {-3, -6, -9}
by definition;
each domain value is paired with exactly one element of range
⇒The given relation {(3, -3), (9, -6) ,(0, -9)} is a function.
(b)
{(3, -3), (9, -6) ,(3, -9)}
Domain is all the x-values, and range is all the y-values.
Domain: {3, 9, 3}
Range: {-3, -6, -9}
since, a function is a relation in which each domain value is paired with exactly one element of range.
In the domain , the value 3 is paired with -3 and -9
⇒the relation {(3, -3), (9, -6) ,(3, -9)} is not a function.
(c)
{(3, -3), (9, -6) ,(9,2), (0, -9)}
Domain is all the x-values, and range is all the y-values.
Domain: {3, 9, 9, 0}
Range: {-3, -6, 2, -9}
In the domain , the value 9 is paired with -3 and -9
⇒the relation {(3, -3), (9, -6) ,(9,2), (0, -9)} is not a function.
(d)
{3, 9, 0, -4}
Since, this does not contains any domain and range values.
therefore, this set is not a function.