FUNCTIONS AND EQUATIONS

This chapter focuses on functions and equations. The circumference of a circle depends on its diameter. According to a rule, the circumference is the product of pi (π) times the diameter. This rule is an example of a function. The chapter explains how to draw a graph, given a function; and how to describe a function, given a graph. A function is a rule assigning exactly one member of one set to each member of another set. A way of picturing the function is to graph it; that is, to represent it on an xy grid. Each pair of numbers in the table of values is a pair of coordinates for a point on the grid. At a glance, the graph reveals essential information about the function. It is usually easier to inspect the graph than to study a table of values or read a description. Linear functions are easier to graph than nonlinear functions because two points determine a line.