EXPONENTIAL FUNCTIONS
Definition of Exponential Function
The exponential function f with base a is denoted by , where , and x is any real number. The function value will be positive because a positive base raised to any power is positive. This means that the graph of the exponential function will be located in quadrants I and II.
For example, if the base is 2 and x = 4, the function value f(4) will equal 16. A corresponding point on the graph of would be (4, 16).
Definition of Logarithmic Function
For x >0, a>0 , and , we have
Since x > 0, the graph of the above function will be in quadrants I and IV.
Comments on Logarithmic Functions
- The exponential equation
could be written in terms of a logarithmic equation as
.
- The exponential equation
can be written as the logarithmic equation .
- Since logarithms are nothing more than exponents, you can use the rules
of exponents with logarithms.
- Logarithmic functions are the inverse of exponential functions. For example if (4, 16) is a point on the graph of an exponential function, then (16, 4) would be the corresponding point on the graph of the inverse logarithmic function.
- The two most common logarithms are called common logarithms and natural logarithms. Common logarithms have a base of 10, and natural logarithms have a base of e.
If you are interested in reviewing any of the following topics, click
the appropriate item:
-
- The properties of logarithms along with examples and problems,
click on Properties
-
- The graphs of logarithms, with examples and problems,
click on Graphs of Logarithms
-
- Change of base with respect to logarithms with examples and problems,
click on Change of base
-
- The three rules of logarithms, with examples and problems,
click on Rules of Logarithms
-
- Solving exponential and logarithms equations with examples and problems,
click on Solving Equations
-
- Solving word problems involving exponential and logarithms functions with examples and problems,
click on Solving Word Problems
[Exponential Rules]
[Logarithms]
[Algebra]
[Trigonometry ]
[Complex Variables]
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