At the end of this chapter, you should be able to:

• evaluate exponential functions using a calculator • state the exponential series for ex • plot graphs of exponential functions • evaluate Napierian logarithms using a calculator • solve equations involving Napierian logarithms • appreciate the many examples of laws of growth and decay in engineering and science • perform calculations involving the laws of growth and decay • reduce exponential laws to linear form using log-linear graph paper

An exponential function is one which contains ex, e being a constant called the exponent and having an approximate value of 2.7183. The exponent arises from the natural laws of growth and decay and is used as a base for natural or Napierian logarithms.