Question

Which set of ordered pairs is not a function? A. (3, 1), (–1,1), (1, 1), (3, −1) B. (–3, 1), (–1, 1), (1, 1), (3, 1) C. (–3, 1), (–1, –1), (1, 1), (3, 1) D. (–3, 1), (–1, –1), (1, 1), (3, −1)

Answer 1

a set is NOT a function when there's an x-coordinate that is repeated

Answer 2

a set is NOT a function when there's an x-coordinate that is repeated, so let's check who is who.


`\bf A.\{(\stackrel{re peat}{3}, 1), (-1,1), (1, 1), (\stackrel{re peat}{3}, -1)\}\quad \otimes\\\\ B.\{(-3, 1), (-1, 1), (1, 1), (3, 1)\}\quad \checkmark\\\\ C.\{(-3, 1), (-1, -1), (1, 1), (3, 1)\}\quad \checkmark\\\\ D.\{(-3, 1), (-1, -1), (1, 1), (3, -1)\}\quad \checkmark`