Which of the following relations is a function? OA. {(3,-1), (2, 3), (3, 4), (1,7)} OB. {(1, 2), (1,3), (2,8), (3,9)} O c. {(3, 0), (4,-3), (6, 7), (4,4)} OD {(1, 2), (2, 3), (3, 4), (4, 5)}
The definition of a function is that every input, x, must have only one output, y. So, for every x value, there should be only one y value with it. If you have two x values that are the same and have different y values, then that is not a function. The only answer that showcases this is letter D.
1 → 2
2 → 3
3 → 4
4 → 5
In this function, every input has one output and each x value is different.
