Answer:
Only A and B are functions
Step-by-step explanation:
When we talk of a function, we refer to a relation in which each input value (x value) has only an output value (y value)
Although, a y-value can have 2 x-value; but under no circumstance is an x-value having 2-y values
Now, let us look at the options;
A) We have a single y-value of 1
All x-values have a single y value of 1 and that makes the relation, a function
B) As we can see, all the x-values have a single y-value; this qualifies as a function
C) x = 3
A graph of this is a straight line, parallel to the y-axis
This shows that all the y-values have a single x-value and as such, this cannot be a function
D) -12 has two y values (8 and 0)
This shows that what we have cannot be a function
