1. 7-3 Logarithmic Functions Today’s Objective: I can write and evaluate logarithmic expressions.

2. Solving exponential equations using common bases Write each side with the same base. Since bases are the same exponents must be equal.

3. Exponential & Logarithm Equations Exponential Equation Inverse Logarithm Equation Exponent/power Base Result Common Log: Logs with a base 10 Written log only – no base # needed Calculator button: [LOG] Read: log base b of a

4. Write in logarithmic form Write in exponential form

5. Solve each equation by using common base method

6. Find the inverse of each function

7. Logarithmic Functions Day 2 Today’s Objective: I can graph a logarithmic function.

8. Earthquakes Richter Scale (magnitude) Intensity Level (Measured on seismometers

9. In December 2004 an earthquake with magnitude 9.3 on the Richter scale hit off the northwest coast of Sumatra. How many times more intense was the December earthquake from the March quake? Earthquakes

10. xy 0 1 2 3 Logarithmic Function: xy 0 1 2 3 1 2 4 8 1 2 4 8 Inverse Domain: Range: Asymptote: Domain: Range: Asymptote: All Real #s Points to note: Logarithms compress a graph x-intercept is (1, 0) unless translated

11. Domain: Range: All Real #s x-intercept: 2 nd Point: Translate: Asymptote: Domain: Range: All Real #s x-intercept: 2 nd Point: Translate: Asymptote: none

12. x-intercept: 2 nd Point: Translate: Asymptote: x-intercept: 2 nd Point: Translate: Asymptote: Domain: Range: All Real #s Domain: Range: All Real #s