Courtney is standing on a mountain above a lake, and she tosses a rock with a velocity of 48ft/sec. Here is a table of vaules that represents the height of the rock, in feet. This is a function

because each input (time) corresponds to exactly one output (height of the rock).

Time (seconds) | Height (feet)
0 | 100
1 | 96
2 | 88
3 | 76
4 | 60
5 | 40
6 | 16
7 | -8

This function represents the height of the rock as it moves through the air after being tossed by Courtney.