Function Relation

[nycmath]

Precalculus
Michael Sullivan
Edition 10
Chapter 2, Section 2.1

Determine whether each relation represents a function.
For each function, state the domain and range.

19. {(2, 6), (-3, 2), (4, 9), (2, 10)}

21. {(1, 3), (2, 3), (3, 3), (4, 3)}

Let me see.

We can see that 19 is not a function because 2 is assigned to two different values. Thus, the domain and range will not be listed.

We can also see that 21 is a function. One unique value in the domain is assigned to one unique value in the range.

Domain = {1, 2, 3, 4}

Range = { 3 }...correct

We do not repeat the same range value. In other words,
Range = {3, 3, 3, 3} is wrong.

You say?

[Eigenvalue]

Yes, both are correct. 21 is the horizontal line y=3.

[nycmath]

Thanks for letting me know that 21 is the horizontal line y = 3.