ABSTRACT
The relationship between two quantities in engineering or science can be expressed graphically, and usually by a formula or equation. This chapter discusses the graphical representation of two quantities related by an equation. Each pair of values obtained from the equation can be used as the co-ordinates of a point on a plane. These points trace out a curve or straight line which is the graph representing the equation. The shape of the graph is a good indication of how one quantity depends on the other. To produce graphs and engineering drawings either by hand or by computer it is necessary to have a method of locating the positions of points on paper or on screen. At least two numbers, called coordinates, are required to locate a point in a plane. Two systems are used: cartesian coordinates system and polar coordinates system. The chapter also discusses quadratic graphs, cubic graphs, exponential graphs, logarithmic graphs, and polar graphs.
