SOLVING LOGARITHMIC EQUATIONS
SOLVING LOGARITHMIC EQUATIONS 
Note:
If you would like an in-depth review of logarithms, the rules of logarithms, logarithmic functions and logarithmic equations, click on logarithmic function.
Solve for x in the following equation.
Example 1:
Note that the domain of 
is the set of real numbers greater than
zero because you cannot take the log of zero or a negative number.
The exact value is 
and the approximate value 
Check the solution by substituting 20.085537 in the original
equation for x. If the left side of the equation equals the right side of
the equation after the substitution, you have found the correct
answer.
You can also check your answer by graphing 
(formed by subtracting the right side of the original equation from
the left side). Look to see where the graph crosses the x-axis; that will be
the real solution. Note that the graph crosses the x-axis at 20.085537.
This means that 20.085537 is the real solution.
If you would like to test yourself by working some problems similar to this example, click on Problem.
If you would like to go back to the equation table of contents, click on Contents.
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