Help!! I don’t understand these

If you don't understand I don't understand too hahahah

First one :

Function? Yes

Domain : { -1 , -2 , -3 }

Range { 10 , 13 , 16 }

Second one:

Function? No

Domain : { 2 , 3 }

Range : { 10 , 13 , 16 }

Third one :

Function ? No

Domain : { 33 , 35 , 36 }

Range : { 8 , 10 }

Step-by-step explanation:

A function is a relation where each input has its own output. In other words a function is a relation where each x value has its own y value. If an x value repeats the relation is not a function.

The domain is the set of x values in a relation whereas the range is the set of y values in a relation

For the first one. No x value repeats, each input has its own output therefore this is a function.

Domain : { -1 , -2 , -3 }

Range { 10 , 13 , 16 }

The second one : The x value 2 repeats therefore the relation is not a function.

Domain : { 2 , 3 }

Range : { 10 , 13 , 16 }

The third one : Each x value has its own y value therefore this relation is a function. ( Note that y values are allowed to repeat )

Domain : { 33 , 35 , 36 }

Range : { 8 , 10 }