A28­3NotesPart1.notebook
October 27, 2015
Algebra 2
Ch.8 Notes Page 47 Part1
P47 8­3 Logarithmic Functions as Inverses
Aug 19­6:20 AM
Logarithms (Logs)
The Log to the base b of a positive number y is defined as...
If y = bx, then logb y = x
log base b of y
b ≠ 1
b > 0
y = bx logb y = x
The log of a negative number or zero is undefined.
A common log is a log that uses base 10.
You can write the common log log10 y as log y
Nov 20­7:23 AM
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A28­3NotesPart1.notebook
October 27, 2015
Writing in Logarithmic Form
y = bx 25 = 52 logb y = x
729 = 36 100 = 1 1/8 = (1/2)3 82 = 64 Nov 20­7:24 AM
Evaluating Logarithms
Evaluate log8 16
log3 81
Write an equation in log form
Convert to exponential form
Write each side using base 2???
Use Power Property of Exponents
Set the Exponents equal
Solve for x
log9 27
log10 100
log64 1/32
Nov 20­7:24 AM
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A28­3NotesPart1.notebook
October 27, 2015
HW #48
8­3 P450 #6,10­12,14­17,19,20,22,24
Please put your name and class period at the top of
the homework. Also include the homework number.
Aug 19­6:25 AM
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