Question

Which is not a function and what is a function

Answer 1

Answers

1. No
2. No
3. Yes
4. No
5. Yes
6. Yes

Explanation - I used the vertical line test to prove if these were a function or not. If the line connects to 2 or more dots then there are 2 or more outputs for every input, so not a function. Note that number 3 has open circles which means the line is more than or less than but not equal to, so that open dot is not a dot so it still passes the vertical line test.