Respuesta :
Answer: D
Step-by-step explanation:
D contains both (2,2) and (2,1), and fails the definition. D(2) would have to be 2 and 1 at the same time.
Set S is a function if and only if
x ∈ S implies x is an ordered pair,
and
(a,b) and (a,c) ∈ S implies b = c.
Answer:
set D
Step-by-step explanation:
For a function we need to have for evety x value, only one value of y.
in set D, we have the points (2, 2) and (2, 1)
this two points have one value of x: x=2
but for the same x we have two values of y: 2 and 1
so this does not obey the requirements to be a functios wich is that for every x, we cannot have more than one value of y.