Question

Determine the value of k so that the relation {(2, 5), (k, 0), (–9, 2), (0, –9)} can be a function

Answer 1

Explanation:

in a function every valid values of x has exactly one assigned y value.

in an ordered pair the first number is x, the second number is y.

the y in (k, 0) is therefore 0.

and this y is different to all other y values in the relation.

therefore, k must be different to all other defined x values (otherwise it would give an x value a second y value, which would make this a not-function).

so, k must be an integer not out of {-9, 0, 2}