8. Logarithmic Functions
8.3 Laws of Logarithms
Class Notes
The McGraw-Hill Ryerson PreCalculus 12 Text is used as the Main Resource.
Assignments in the Powerpoint Lesson Plans refer to pages and questions in the PreCalculus 12 text.
8.3 Laws of Logarithms (revised)
Connection to TRANSFORM and Pedagogical Shifts
The PowerPoint lesson guide above has been changed to incorporate the Student as Inquirer and Creator to discover the laws of logarithms. Students use their knowledge of benchmark logarithms to calculate the sum of two logarithms. Students then write an equivalent expression for the value as a logarithm.
We filled in the LHS first to develop a pattern.
Then we looked at the RHS. Students were asked make a connection between the arguments of the logs being added to the result. "What mathematical operation with 8 and 4 results in 32?" Many students were able to discover that the operation had to be multiplication and were able to complete the rule.
After the students made a conjecture for the rule of adding logarithm expressions with the same base, the rule was derived. Take a look at the PowerPoint lesson to see more.
Worksheets
