Questions over 4.6 HW???

4.7 (Green)Solve Exponential and Logarithmic Equations

No School: Monday

Logarithms Test: 1/21/10 (Thursday)

Vocabulary:

Exponential equations are equations in which variable expressions occur as exponents.

Logarithmic equations are equations that involve logarithms of variable expressions.

Vocabulary:

Property of Equality for Exponential Equations: If b is a positive number other than 1, then bx = by

if and only if x = y.

Property of Equality for Logarithmic Equations: If b, x, and y are positive numbers with b = 1, then

logbx = logby if and only if x = y.

Example 1:

Solve 8x = 4x + 1

You Try:

Solve 53x + 1 = 25x + 1

Example 2:

Solve 8x = 23

You Try:

Solve 43x = 9

Example 3:

Solve log8(x + 6) = log8(4 – x)

You Try:

Solve

1. log7(x + 2) = log7(2 – 3x)

2. ln(4 – 5x) = ln(x + 10)

Example 4:

Find the solution(s) of log x + log(x + 3) = 1

You need to check

for extraneous

solutions….fakers!

You Try:

Solve

1. log6 x + log6(x – 5) = 2

2. 2 ln x = ln(2x – 3) + ln(x – 2)

Homework:

Pg. 161 #1-41odd

You need to practice!

Your FIRST test (55% of your grade) is next THURSDAY!!!!