Consider the graph below. The dot on the graph represents the position of a train at a particular time. The cross-hairs represent the time. Adjust the time by sliding cross-hairs left and right. Notice that the train’s distance, in miles, from downtown depends on the time, in hours, after $8$ a.m. How far from downtown is the train $2$ hours after $8$ a.m.? ? miles hours miles per hour hours per mile Without knowing anything about function notation, you can still use a language you already know, English, to describe information about the train. For instance:

• The train can only be in one place at any particular time.
• As time passes the train gets farther from downtown.
• The speed of the train changes during its trip.

There are also some characteristics of the graph itself you can also describe in English:

• The graph rises as we read it from left to right.
• Sometimes the graph is curved upwards.
• Sometimes the graph curves downwards.
• Some parts of the graph are steeper than others.