RULES OF LOGARITHMS - Example

Let a be a positive number such that a does not equal 1, let n be a real number, and let u and v be positive real numbers.

Logarithmic Rule 3: .

Example 4: Find .

Solution: You cannot take the log of a negative number. In terms of exponents, there is no exponent t such that will equal a negative number.

Example 5: Find .

Solution: Since is a positive number, you can find the log. Then

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Note: You cannot use Logarithmic Rule 3 to simplify the expression to because you cannot take the log of a negative number.

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Author: Nancy Marcus