Question: how can you determine whether a relation is a function or not??? how???

Step-by-step explanation:

A relation is a function if  values in the Domain ( x values) only map to one  value of the range (y values).

For example y = x + 1 is a function but  x^2 + y^2 = 4 is not  because  when x = 0, y can be -2 or 2.

If we have a graph of a function it will pass the vertical line text. That is any vertical line drawn through the graph will only pass through it once.

x^2 + y^2 = 4 is a circle so a vertical line will pass through it  at 2 points.

the answer is d. 75%