Question

relation or function? {(10,2), (-10,2), (6,4), (5,3), (-6,7)}

Answer 1

Here each x-coordinate is unique and it maps into some y. So it is a function.

Answer 2

check if it has any REPEATED X-VALUES
if it does, then is NOT a function

Answer 3

No, @jdoe0001, it is still a function unless the repeated x-values have different y-values.

Answer 4

Each x-value must have a unique y-value. x-values can be repeated so long as they always map to the same y-value.

Answer 5

hmmmm

Answer 6

a function is a unique mapping of x to y.

Answer 7

If the same x-value maps into more than one y-value then it fails the vertical line test for functions and therefore it will not be a function.

Answer 8

if the same "x" value maps to a different y-value... .then the vertical line test would not be satisfied

Answer 9

right.

{(1,3),(2,3)} is a function
{(1,3),(1,3)} is a function
{(1,3),(1,4)} is not a function

Answer 10

and of course for completeness

{(1,3),(2,4)} is a function but I doubt there was any confusion on that point

Answer 11

splitting hair there =)