Question

Which relation is not a function

A.){(4,5), (-2,3), 0,-9), (2,4)}


B.) {(−1,2), (0,5), (-1,0), (2,-2)}


C.) {(6,7), (8,9), (−3,6), (3,4)}


D.) {(2,4), (1,3), (9,5), (4,7)}

Answer 1

By definition a function can have only one value of y for any given value of x.

Since B. contains both (-1,2) and (-1,0), y has two values for the same value of x and thus B. cannot be a function...