Logarithmic Functions









Properties of Exponents and Logarithms

Properties of Exponents and Logarithms Then the following properties of ... Most calculators can directly compute logs base 10 and the natural log.
Exponents and Logarithms


6.2 Properties of Logarithms

(Inverse Properties of Exponential and Log Functions) Let b > 0 b = 1. We have a power
S&Z . & .


1 Definition and Properties of the Natural Log Function

Lecture 2Section 7.2 The Logarithm Function Part I. Jiwen He. 1 Definition and Properties of the Natural Log. Function. 1.1 Definition of the Natural Log 
lecture handout


Logarithmic Functions

Natural Logarithmic Properties. 1. Product—ln(xy)=lnx+lny. 2. Quotient—ln(x/y)=lnx-lny. 3. Power—lnx y. =ylnx. Change of Base. Base b logax=logbx.
LogarithmicFunctions AVoigt





Elementary Functions Rules for logarithms Exponential Functions

We review the properties of logarithms from the previous lecture. In that By the first inverse property since ln() stands for the logarithm base.
. Working With Logarithms (slides to )


LOGARITHME NEPERIEN

Preuve : Les démonstrations se font principalement en utilisant les propriétés de la fonction exponentielle. • e ln a + ln 
ln


Algebraic Properties of ln(x)

simplify the natural logarithm of products and quotients. If a and b are positive numbers and r is a rational number we have the following properties:.
Calculating With Logarithms


11.4 Properties of Logarithms

a. The first thing we must do is move the coefficients from the front into the exponents by using property 3. This gives us. 4 ln 2 + 2 ln x – ln y = ln 24 





Elementary Functions The logarithm as an inverse function

then the properties of logarithms will naturally follow from our understanding of exponents. ln(x) and speak of the “natural logarithm”.
. Logarithms (slides to )


PROPERTIES OF LOGARITHMIC FUNCTIONS

log is often written as x ln and is called the NATURAL logarithm (note: 59. 7182818284 .2. ≈ e. ). PROPERTIES OF LOGARITHMS. EXAMPLES.
properties of logarithms


209565 Logarithmic Functions

Logarithmic Functions

y=logax x=ay (exponential form)

Properties of Logarithms

1. loga1=0 because a0=1

2. logaa=1 because a1=a

3. logaax=x and =x Inverse Property

4. If logax=logay then x=y One-to-one

Natural Logarithms

y=lnx if x=ey

Properties of Logarithms

1. ln1=0 because e0=1

2. lne=1 because e1=e

3. lnex=x and elnx=x inverse properties

4. If lnx=lny then x=y one-to-one

Logarithmic Properties

1. Productloga(xy)=logax+logay

2. Quotientloga(x/y)=logax-logay

3. Powerlogaxy=ylogax

Natural Logarithmic Properties

1. Productln(xy)=lnx+lny

2. Quotientln(x/y)=lnx-lny

3. Powerlnxy=ylnx

Change of Base

Base b

logax=logbx logba

Base 10

logax=log10x log10a

Base e

Logax=lnx

lna Use the definition of Logarithmic Function to evaluate each logarithmic for indicated value of x a. f(x)=log2x, x=32 y=log232

2y=32 exponential form

2y=25 y=5 b. f(x)=log10x, x=1/100 y=log10(1/100)

10y=1/100

10y=10-2

y= -2

Use calculator to evaluate the function

a. log1010 = 1 b. log102.5 = .3979400 c. ln2 = .6931472 d. ln(-1) = ERROR domain of lnx is the set of positive real numbers, ln(-1) is undefined e. log10(-2) = ERROR domain of lnx is the set of positive real numbers, ln(-1) is undefined (Note using a calculator can only be used with functions of base 10 or base e, also called the common logarithmic function, so you may need to use the Change of Base formula, as shown below.)

Changing base using common logarithms

a. log425 log1025 Change of Base log104

1.39794 § 2.32

.60206 b. log425 (use Natural Logarithms) ln25 ln4

3.21888 § 2.32

1.386

Write each logarithm in terms of ln2 and ln3

a. ln6 ln(2 X 3) ln2 + ln3 Product Property b. ln(2/27) ln2-ln27 Quotient Property ln2-ln33 ln2-3ln3 Power Rule

Expand or condense each expression

Expand

a. ln( ¥3x-5 / 7) ln[ (3x-5)1/2/ 7] ln(3x-5)1/2-ln7 Quotient Property

½ ln(3x-5)-ln7 Power Property

Condense

b. 1/3[log2x+log2(x-4)]

1/3[log2x(x-4)] Product Property

log2[x(x-4)] 1/3 Power Property log23¥x(x-4))

Logarithmic Functions

y=logax x=ay (exponential form)

Properties of Logarithms

1. loga1=0 because a0=1

2. logaa=1 because a1=a

3. logaax=x and =x Inverse Property

4. If logax=logay then x=y One-to-one

Natural Logarithms

y=lnx if x=ey

Properties of Logarithms

1. ln1=0 because e0=1

2. lne=1 because e1=e

3. lnex=x and elnx=x inverse properties

4. If lnx=lny then x=y one-to-one

Logarithmic Properties

1. Productloga(xy)=logax+logay

2. Quotientloga(x/y)=logax-logay

3. Powerlogaxy=ylogax

Natural Logarithmic Properties

1. Productln(xy)=lnx+lny

2. Quotientln(x/y)=lnx-lny

3. Powerlnxy=ylnx

Change of Base

Base b

logax=logbx logba

Base 10

logax=log10x log10a

Base e

Logax=lnx

lna Use the definition of Logarithmic Function to evaluate each logarithmic for indicated value of x a. f(x)=log2x, x=32 y=log232

2y=32 exponential form

2y=25 y=5 b. f(x)=log10x, x=1/100 y=log10(1/100)

10y=1/100

10y=10-2

y= -2

Use calculator to evaluate the function

a. log1010 = 1 b. log102.5 = .3979400 c. ln2 = .6931472 d. ln(-1) = ERROR domain of lnx is the set of positive real numbers, ln(-1) is undefined e. log10(-2) = ERROR domain of lnx is the set of positive real numbers, ln(-1) is undefined (Note using a calculator can only be used with functions of base 10 or base e, also called the common logarithmic function, so you may need to use the Change of Base formula, as shown below.)

Changing base using common logarithms

a. log425 log1025 Change of Base log104

1.39794 § 2.32

.60206 b. log425 (use Natural Logarithms) ln25 ln4

3.21888 § 2.32

1.386

Write each logarithm in terms of ln2 and ln3

a. ln6 ln(2 X 3) ln2 + ln3 Product Property b. ln(2/27) ln2-ln27 Quotient Property ln2-ln33 ln2-3ln3 Power Rule

Expand or condense each expression

Expand

a. ln( ¥3x-5 / 7) ln[ (3x-5)1/2/ 7] ln(3x-5)1/2-ln7 Quotient Property

½ ln(3x-5)-ln7 Power Property

Condense

b. 1/3[log2x+log2(x-4)]

1/3[log2x(x-4)] Product Property

log2[x(x-4)] 1/3 Power Property log23¥x(x-4))
  1. log ln properties
  2. ln properties logarithm
  3. logarithmic properties ln