Download Logarithms

Logarithms
1
Review of exponent rules:
1. x1/2 = √x
2. x1/3 = ∛x
3. x2/3 = (∛x)2
4. x-1 = 1/x
5. 1/x-1 = x
2
Definition of Logarithm
k
log N = k if and only if b = N
b
log b b = 1
log b 1 = 0
y=x
y=x
f(x) = 2
x
-1
f (x) = log x
2
f(x) = 2
x
The inverse of f, the exponential function
with base 2, is called the logarithmic function
with base 2
3
Write the equation in
exponential form:
1. log 36 = 2
6
62 = 36
k
Hint: Use log b N = K if and only if b = N
2. log 2 2 = 1
21 = 2
3. log10 (.001) = -3
4
Write each equation in
logarithmic form:
4. 6 0 = 1
5. 8
-2/3
=
1
4
5
Simplify each logarithm
6. log 5 25
7. log 2 8√2
6
Solve for x.
8. log5 x = 3
9. logx 5 = ­1
7
Homework
Worksheet 10­4
8