Sullivan Algebra and Trigonometry: Section 6.5 Properties of Logarithms Objectives of this Section Work With the Properties of Logarithms Write a Log Expression as a Sum or Difference of Logarithms Write a Log Expression as a Single Logarithm Evaluate Logarithms Whose Base is Neither 10 nor e

Properties of Logarithms

Write the following expression as the sum and/or difference of logarithms. Express all powers as factors.

Write the following expression as a single logarithm.

Theorem: If N = M, then Theorem: If, then N = M. These properties become critical when solving exponential and logarithmic equations, covered in the next section.

Most calculators only evaluate logarithmic functions with base 10 or base e. To evaluate logs with other bases, we use the change of base formula.