ABSTRACT
At the end of this chapter, you should be able to:
• understand what is meant by determination of law • prepare co-ordinates for a non-linear relationship between two variables • plot prepared co-ordinates and draw a straight line graph • determine the gradient and vertical-axis intercept of a straight line graph • state the equation of a straight line graph • plot straight line graphs involving practical engineering examples • determine straight line laws involving logarithms: y = axn, y = abx and y = aebx • plot straight line graphs involving logarithms
In Chapter 31 we discovered that the equation of a straight line graph is of the form y = mx + c, where m is the gradient and c is the y-axis intercept. This chapter explains how the lawof a graph can still be determined evenwhen it is not of the linear form y = mx + c. The method used is called determination of law and is explained in the following sections.
