Practical Algebra, 3rd Edition

10EXPONENTIAL FUNCTIONS

So far, we have worked with polynomial functions. In this chapter, we briefly introduce another important type of function called an exponential function, which has its variable in the exponent. These functions are incredibly useful because they can model a great deal of real-world behavior, from the population of bacteria to the amount of money in your bank account.

10.1 Graphing Exponential Functions

A famous problem, first known to have been recorded by the 13th-century Muslim scholar Ibn Khallikān, has been used to illustrate exponential growth for hundreds of years: if an 8x8 chessboard has grains of wheat placed on each of its 64 squares such that 1 grain is placed on the first square, 2 on the second, 4 on ...