Graphs and Graphing

There are many practical applications of graphs and graphing. In the sciences and engineering, sets of numbers represent physical quantities. Graphing the relationship between these quantities is an useful tool for understanding nature. One specific example is the graphing of current versus voltage, used by electrical engineers, to picture the behavior of various circuit components. The rectangular coordinate system can be used to represent all possible combinations of current and voltage. Nature, however, severely limits the allowed combinations, depending on the particular electrical device through which current is flowing. By plotting the allowed combinations of current and voltage for various devices, engineers are able to "picture" the different behaviors of these devices. They use this information to design circuits with combinations of devices that will behave as predicted.