CHAPTER FOUR - EXPONENTIAL AND LOGARITHMIC FUNCTIONS

Abstract

This chapter discusses exponential function and its inverse and the logarithmic function. Exponential functions apply in nature and are useful in chemistry, biology, and economics as well as in mathematics and engineering. The chapter discusses the applications of exponential functions in calculating such quantities as compound interest and the growth rate of bacteria in a culture medium. In many business transactions, the interest that is added to the principal at regular time intervals also earns interest. This is called the compound interest process. The time period between successive additions of interest is known as the conversion period. Thus, if interest is compounded quarterly, the conversion period is three months; if interest is compounded semiannually, the conversion period is six months. Logarithms can be viewed as another way of writing exponents. Historically, logarithms have been used to simplify calculations; in fact, the slide rule, a device long used by engineers, is based on logarithmic scales. In today's world of inexpensive hand calculators, the need for manipulating logarithms is reduced. The chapter presents computing with logarithms that provide enough background to allow one to use this powerful tool but omits some of the detail found in older textbooks.