# Objective:   Discover and use the properties of logarithms. 8­4 Properties of Logarithms April 06, 2009

```8&shy;4 Properties of Logarithms
April 06, 2009
8&shy;4 Properties of Logarithms
Objective: Discover and use the properties of logarithms.
Mar 20&shy;12:58 PM
1
8&shy;4 Properties of Logarithms
April 06, 2009
Check Skills You'll Need
Simplify each expression.
1. log2 4 + log2 8 2. log3 9 &shy; log3 27
3. log2 16/log2 64
Evaluate each expression for x = 3.
4. x3 &shy; x
5. x5 x2
6. x6/x9
7. x3 + x2
Mar 20&shy;1:07 PM
2
8&shy;4 Properties of Logarithms
April 06, 2009
With your partner or group, complete the Properties of Logarithms Activity.
Mar 20&shy;1:19 PM
3
8&shy;4 Properties of Logarithms
April 06, 2009
From your activity, you should have discovered the following properties:
You can use the properties of logarithms to rewrite logarithmic expressions.
Mar 20&shy;1:22 PM
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8&shy;4 Properties of Logarithms
April 06, 2009
Identifying the Properties of Logarithms
State the property or properties used to rewrite each expression:
a. log2 8 &shy; log2 4 = log2 2
b. logb x3y = 3 logb x + logb y
Mar 20&shy;1:29 PM
5
8&shy;4 Properties of Logarithms
April 06, 2009
Simplifying Logarithms
Write each logarithmic expression as a single logarithm.
a. log3 20 &shy; log3 4
b. 3 log2 x + log2 y
c. 3 log 2 + log 4 &shy; log 16
Mar 20&shy;1:43 PM
6
8&shy;4 Properties of Logarithms
April 06, 2009
Expanding Logarithms
Expand each logarithm.
a. log5 (x/y)
b. log 3r4
c. log2 7b
d. log (y/3)2
e. log7 a3b4
f. log √3b Mar 20&shy;1:47 PM
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8&shy;4 Properties of Logarithms
April 06, 2009
HOMEWORK
p. 457 #2&shy;30 even, 33&shy;41
Mar 20&shy;2:05 PM
8
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