1. Properties of Logs Objective: Be able to use the properties of logarithms to expand and condense expressions. TS: Make decisions after reflection and review Warm-Up: 1)Use the change of base formula to rewrite log a 7 as a ratio of (a) common logs and then (b) as a ratio of natural logs 2)Use your calculator to find log 20 130

2. Properties of Logarithms log b x + log b y = __________ log b x – log b y = __________ log b x a = ____________ Likewise… ln x + ln y = ln (xy) ln x – ln y = ln (x/y) lnx a = a(ln x) And don’t forget about Change of Base!

3. Use the properties to verify

4. Use the properties to fully expand

7. Use the properties to condense to a single logarithm

10. Given log x 2 = 3.28 and log x 3 = 4.02 and log x 5 = 5. Find log x 1.2