Label the following as a function or NOT a function?

Question

Is this a function?

 

 

(3,5)(-1,4)(2,5)(0,0)

Answer 1

Yes. This represents a function with domain {-1,0,2,3} because in this set, knowing x uniquely gives f(x).

 

 

x = -1 ⇒ f(x) = 4

 

x = 0 ⇒ f(x) = 0

 

x = 2 ⇒ f(x) = 5

 

x = 3 ⇒ f(x) = 5