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Activity 37. Logarithmic Functions (Section 5.2, pp. 398-405). Definition:. Let a be a positive number with a ≠ 1. The logarithmic function with base a, denoted by log a , is defined by. Properties of Logarithms (3 step proofs):. Let a be a positive number with a ≠ 1. Example 1:.
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Activity 37 Logarithmic Functions (Section 5.2, pp. 398-405)
Definition: Let a be a positive number with a ≠ 1. The logarithmic function with base a, denoted by loga, is defined by
Properties of Logarithms (3 step proofs): Let a be a positive number with a ≠ 1
Example 1: Change each exponential expression into an equivalent expression in logarithmic form:
Example 2: Change each logarithmic expression into an equivalent expression in exponential form:
Example 3: Evaluate each of the following expressions: Property 3 Property 3 Property 3
Property 4 Property 3 Property 1
Example 4: Find the domain of the function and sketch its graph.
Common Logarithms: The logarithm with base 10 is called the common logarithm and is denoted by omitting the base: log x := log10 (x).
Example 5 (Bacteria Colony): A certain strain of bacteria divides every three hours. If a colony is started with 50 bacteria, then the time t (in hours) required for the colony to grow to N bacteria is given by Find the time required for the colony to grow to a million bacteria.
Definition: Natural Logarithms The logarithm with base e is called the natural logarithm and is denoted by ln: ln x := loge x. We recall again that, by the definition of inverse functions, we have
Example 6: Evaluate each of the following expressions: Property 3 Property 3 Property 4
Example 7: Graph the function
Example 8: Find the domain of the function