Review
Rewrite each equation in exponential form.
1) log12 144 = 2
2) log 10 = 1
Rewrite each equation in logarithmic form.
3) 43 = 64
4) 54 = 625
Evaluate each expression.
5) log5 125
6) log9 729 Key Concpets for Sect. 8.4
log 20=
log 4 + log 5 =
log 10 + log 2 =
log 20 + log 1 =
log 16 =
log 8 + log 2 =
log 4 + log 4 =
log 16 + log 1 =
log 24 = log 8 + log 3 =
log 6 + log 4 =
log 12 + log 2 =
log 24 + log 1 = What is the rule?
Key Concepts for Sect. 8.4
log 3/4 =
log 3 ­ log 4 =
log 2/5 = log 2 ­ log 5 =
log 3/2 = log 3 ­ log 2 =
log 7/2 =
log 7 ­ log 2 =
What is the rule?
Key Concepts for Sect. 8.4
log 23 =
3log 2 =
log 32 =
2log 3 =
log 24 =
4log 2 =
log 35 =
5log 3 =
What is the rule?
Key Concepts for Sect. 8.4
*Three properties of logarithms are below:
logb n m = logb n + logb m
n
logb = log
b n ­ logb m
m
logb nm = m logb n
Guided Practice for Sect. 8.4
Ex 1: Write each expression as a single logarithm.
a) log2 8 + log2 4
b) log3 20 ­ log3 4
c) 3log2 x + log2 y
Guided Practice for Sect. 8.4
Ex 2: Expand each logarithm.
a)
b)
c)
d)