Question

Which of the following sets represents a function?
{(3, 5), (-1, 7), (3, 9)}
{(1, 2), (3, 2), (5, 7)}
{(1, 2), (1, 4), (1, 6)}

Answer 1

(3,5), (-1,7), (3,9)
(1, 2), (1, 4), (1, 6)
these 2 sets represent a function, this is because for functions for every x value there is F(x) value.
As you can see for (1, 2), (3, 2), (5, 7) you can see that when x = 1 and when x=3 the value of f(x)= 2. This is why this one is not a function.