The Nature of Mathematics, 12th Edition
Home
about dr. smith
glossary
transparencies
other books

Chapter1
Chapter 2
Chapter 3
Chapter 4
Chapter 5
Chapter 6
Chapter 7
Chapter 8
Chapter 9
Chapter 10
Chapter 11
Chapter 12
Chapter 13
Chapter 14
Chapter 15
Chapter 16
Chapter 17
Chapter 18
group projects
individual projects
links by topic
Section 10.1: Exponential Equations

10.1 Outline

A. Exponential equation
     1. definition
     2. evaluate exponentials
B. Definition of logarithm
     1. notation, logarithm, and argument
     2. common logarithm
     3. natural logarithm
C. Evaluating logarithms
     1. evaluate
     2. using calculators
     3. change of base
     4. exact solution
D. Exponential equations 
     1. three types
         a. base 10
         b. base e
         c. base b
     2. micometer 

10.1 Essential Ideas

An equation of the form bx = N in which an unknown value is included as part of the exponent is called an exponential equation.  For positive b and A, b not equal to 1,
x = logb A; x is called the logarithm and A is called the argument.
                 
common logarithm is base 10; log x means log10x
                 
natural logarithm is base e; ln x means logex

In order to change from one base to another, use logax = logbx/logba.

Exponential equations fall into one of three types:
                base 10; 10x = 5
                base e; e-0.06x = 3.456
                base b (arbitrary base); 8x = 156.8