Question

how can you determine if the inverse {(9,-3),(4,-2),(9,3),(1,-1)} is a function?

Answer 1

For every x, there must be one y output.

Answer 2

Something like this is not a function: http://www.mathsisfun.com/sets/images/relation-not-function.gif

Notice how 5 has more than one output.

Answer 3

Or use the vertical line test, if it passes the more than once, it's not a function.

Answer 4

In your example, 9 has more than one y output. So it is not a function.

Answer 5

ok it does make sense and thank u for that

Answer 6

You're welcome~