ABSTRACT
At the end of this chapter, you should be able to:
• understand logarithmic scales • understand log-log and log-linear graph paper • plot a graph of the form y = axn using log-log graph paper and determine constants ‘a’ and ‘n’ • plot a graph of the form y = a bx using log-linear graph paper and determine constants ‘a’ and ‘b’ • plot a graph of the form y = aekx using log-linear graph paper and determine constants ‘a’ and ‘k’
Graph paper is availablewhere the scalemarkings along the horizontal and vertical axes are proportional to the logarithms of the numbers. Such graph paper is called log-log graph paper. A logarithmic scale is shown in Fig. 39.1where the distance between, say 1 and 2, is proportional to lg 2− lg 1, i.e. 0.3010 of the total distance from 1 to 10. Similarly, the distance between 7 and 8 is proportional to lg 8− lg 7, i.e. 0.05799 of the total distance from 1 to
10. Thus the distance between markings progressively decreases as the numbers increase from 1 to 10.
