1. Chapter 3.4 Properties of Log Functions Learning Target: Learning Target: I can find the inverses of exponential functions, common logarithms (base 10), natural logarithms (base e), graphs of logarithmic functions, and measuring sound using decibels

2. Properties of Logs Product Rule: log b (RS) = log b R + log b S Quotient Rule: log b (R/S) = log b R – log b S Power Rule: log b (R c )= c log b R

3. Example Expand the log of a product Log (8xy 4 ) Expand the log of a quotient ln[(x 2 + 5) 1/2 /x]

4. Changing the base Graph y = log 4 7. What problem do you have? Is there a log 4 button on your calculator? The following steps will give us a method for changing the base to something more desirable. 4 y = 7 ln 4 y = ln 7 y ln 4 = ln 7 y = ln 7/ ln 4

5. Thus the Change of Base Formula Log b x = lnx/lnb

6. Homework Pg. 317 # 3 – 45 every 3 rd