Answer:
Explanation:
- First you need to know what a function is.
A function is a rule that states that for every input there is exactly ONE output.
- Choice 1 is wrong because x has 2 values of y (-1,10) and (-1, 9)
- Choice 2 is wrong also because x has 2 values of y (7,8) and (7,9)
- Choice 3 is correct because for every value of x there is exactly ONE y-value
- Choice 4 is wrong because x has 2 values of y (-5, 10) and (-5,16)
TIP:
- A function is also proved to be a function if it passes the vertical line test. It's a test where you draw vertical lines across the graph and it MUST hit the graph once for every vertical line you make. So you can visualize that coordinates (7,8) and (7,9) would be stacked on each other and when you make a vertical line, it would hit the graph twice, therefore, proving that it is not a function
Hope this helped!