Question

I will medal & fan plus a testimonial.(:


Which of the following represents a function?

A.) x: -2 , -1 , 0 , -1 , -2
y: 2 , 3 , 4 , 5 , 6
B.) x- 1, 2 , 3 , 4 , 5
y- 5 , 4 , 3 , 2 , 1
C.) x- 1, 2 ,1 , 1 , 2 , 1
y- 0 , 1 , 2 , 3 , 4
D.) x- 1 , 1, 1, 1 , 1
y- 2 , 3 , 4 , 5 , 6

Answer 1

If you have two or more y values for the same x value, then you don't have a function.

You can see this visually by graphing the points and using a vertical line test. If you can draw a vertical line through two or more points, then you don't have a function.

So graphing answer A, we see that we can draw a vertical line through points (-2,2) and (-2,6) and we can draw a vertical line through points (-1,3) and (-1,5). So this answer fails to be a function on two occasions.

Since you now know answer A is no good, test the other three answers.