laws

1
laws
of
logarithms
2
Product law of logarithms when adding two logs
together multiply the exponent of the log and
keep the base. Exlogab logac logabc
laws
To solve a logarithm you must have the same base
if they dont then dived the exponent to the
power of ten by the base to the power of ten thus
giving you to logs to the power of ten. Ex
logaBlogb/loga
Special logarithm laws a log with the same base
and exponent equals 1 and a log with an exponent
of one equals 0. ex logaa 1                    
      loga1 0
Power law of logarithms when the exponent of the
log has an exponent move that exponent to the
front of the log. Exlogabx x logab  
Quotient law of logarithms when subtracting logs
divide the exponent of the log and keep the base.
exlogab - logac loga(b/c)
3
example problems 1
log 20 - log 15
log 5 log 2
10
10
10
10
log 13 - log 8
log 15 log 9
10
10
10
10
Logs with a base of 10 Simplify the equations to
1 term
4log 2
2log 8 log 3
10
10
10
1
log 35
-
10
2
2log 8 log 6 - log 3
10
10
10
4
example problems 2
X
log 6 - log 3
4
4
X
log 2 log 2
2
2
Logs without a base of 10 Solve for x
X
3log 4 log 5
2
2
X
log 10 log 19
3
3
5
example problems 3
x
7 23
x
5 125
Solve for x
log 9
35
x
log 3 log 5
12
x
x
6
example problems 4
Evaluate the following
Solve for x
log 5 2log 5
log 64
log 20
x
x
4
5
log 6
5
x3
3
(2 )(2 )
x
14
log 15
6
log 0.5
x2
4
29
4
log 0.9
5
2
log 1.3
8
7
possible quiz questions
Fun practice quiz questions
Lets see what we have learned from all this
http//library.thinkquest.org/C0110248/algebra/isl
quiz.htm
8
bibliography
http//library.thinkquest.org/C0110248/algebra/isl
quiz.htm