Which relation is a function?

The relation { (3,4), (-3, 8), (6,8) } is a function.

Explanation:

Choice A can be ruled out because we have x = -3 repeat itself for different y values. For any x input, there must be exactly one y output. This is assuming the x value is in the domain of course.

Choice C can be ruled out for similar reasoning. This time x = 3 repeats.

Choice D is the same story, but we go back to x = -3 showing up twice.

Choice B is the only thing left. Each x value is unique or only written one time. This graph passes the vertical line test. The other graphs fail the vertical line test (it is possible to draw a vertical line through more than one point).

quit

step-by-step explanation: