Common Core: F-IF.1
Problem 11 of 18a1-011
Each relation below is a set of ordered pairs , where is the input and is the output. Which relation is a function?
Try it first
The walkthrough opens once you check an answer.
Solution walkthrough1:56
- A function gives each input exactly one output. In each pair , is the input, the output.
- In A, the input is paired with and with . One input, two outputs: A is not a function.
- In B the outputs are all different, but the input goes to and to . B is not a function.
- In D, the input goes to and to . Those are different outputs, so D is not a function.
- In C each input has one arrow. Two arrows land on , and that is allowed. C is a function.
- Check the inputs, not the outputs. A repeated output is fine; one input with two outputs is not.