2.If then
To solve logarithmic equations, use these properties, where
First use the properties of
Section 10.4,if necessary, to write the equation in the
proper form.
1.If then
2.If then
Always check proposed solutions in logarithmic equations.
logb x=y, by=x.
logb x=logb y, x=y.
b 7 0, bZ1, x 7 0, y 7 0.
x=y, x 7 0, y 7 0, logb x=logb y. Solve.
Take common logarithms.
Power rule
Divide by log 5.
The solution set is
Solve.
Subtract x.
This value checks, so the solution set is
Solve.
Exponential form
Apply the exponent.
Add 1.
Divide by 3.
This value checks, so the solution set is E^173 F.
x=
17
3
3 x= 17
3 x- 1 = 16
3 x- 1 = 24
log 2 13 x- 12 = 4
516.
x= 1
2 x=x+ 1
log 3 2 x=log 3 1 x+ 12
5 1.2920 6.
m=
log 8
log 5
L1.2920
m log 5=log 8
log 5 m=log 8
5 m= 8
CONCEPTS EXAMPLES
REVIEW EXERCISES
CHAPTER 10
10.1 Determine whether each graph is the graph of a one-to-one function.
1. 2.
0
x
y
0
x
y
626 CHAPTER 10 Inverse, Exponential, and Logarithmic Functions
Determine whether each function is one-to-one. If it is, find its inverse.
3.ƒ 1 x 2 =- 3 x+ 7 4.ƒ 1 x 2 = 236 x- 4 5.ƒ 1 x 2 =-x^2 + 3