Properties of Logarithms:

Lesson 53

LESSON OBJECTIVE:

1)Simplify and evaluate expressions using the properties of Logarithms.2)Solve logarithmic equations using the properties of logarithmic properties.

DEFINITIONS:

1)Common logarithms – written without the subscript 10.2)Change of Base Formula – allows you to write equivalent logarithmic expressions that have different bases.

Properties of Logarithms:

loga1 = 0logaa = 1logaax = x a xa xlog If logax= loga ythen x = y

because a0 = 1because a1 = a

log ( ) log loga a auv u v

log log loga a a

u

vu v

Quotient Property

Product Property

Properties of Logarithms:

loglog

loga xx

a 10

10Change-of-

Base

log logan

au n uPower Property

Please get out the worksheet “Study Guide and Intervention- Properties of Logarithms” and “Study Guide and Intervention- Common Logarithms” so I can show you examples of how to solve examples of logarithmic properties.

HOMEWORK!!

1)“Practice- Properties of Logarithms” Worksheet.2)“Study Guide and Intervention- Common Logarithms” Worksheet.