Algebra 2 Lesson 10-3: Properties of Logarithms

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Algebra 2 Lesson 10-3Properties of Logarithms

• Another fine slide show by S. Coker ?

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Things to KNOW
The Product Property logb mn logb m
logb n
The Power Property logb mp plogb m
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Use log12 3 0.4421 log12 7 0.7831 to
evaluate
log12 3 7
A) log12 21
Use your Product Property logb mn logb m
logb n
21 can be rewritten as 3 7.
log12 3 log12 7
Now replace with the given information.
0.4421 0.7831
1.2252
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Use log12 3 0.4421 log12 7 0.7831 to
evaluate
log12 7 - log12 3
0.7831 - 0.4421
Now replace with the given information.
.3410
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Use log12 3 0.4421 log12 7 0.7831 to
evaluate
log12 72
C) log12 49
49 can be rewritten as 72.
Use your Power Property logb mp plogb m
2 log12 7
Now replace with the given information.
2 0.7831
1.5662
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Use log12 3 0.4421 log12 7 0.7831 to
evaluate
log12 3 12
D) log12 36
36 can be rewritten as 3 12.
Use your Product Property logb mn logb m
logb n
log12 3 log12 12
0.4421 1
Now replace with the given information.
1.4421
Notice log12 12 1
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Use log12 3 0.4421 log12 7 0.7831 to
evaluate
E) log12 48
48 cannot be written as a product of 3 and 7.
log12 12 log12 12 - log12 3
1 1 - 0.4421
1.5579
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Use log12 3 0.4421 log12 7 0.7831 to
evaluate
log12 36 - log12 49
We know these from the other examples.
1.4421 1.5662
-.1241
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The End!