Exercise 34 Page 45

The independent variable of a graph will always be represented by the $x\text{-}$axis. Since the value of the car is dependent on the passage of time, time is the independent variable. To graph the car's value over time, we should have time on the $x\text{-}$axis and value on the $y\text{-}$axis.

Three pieces of information will help us draw the graph.

1. The car has an initial, but unknown, value.
2. The value decreases over time.
3. The value decreases quickly in the first few years.

If we say the initial value of the car was $a,$ our graph should represent the car's value at the time of purchase, $t=0.$ The graph should then show the value decreasing rapidly at first and then continuing to decrease at a slower rate after that.