Solving Logarithmic and Exponential Equations · 2017-02-07 · 8 Notes Solving Logarithmic and...

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8 Notes Solving Logarithmic and Exponential Equations LB.notebook 1 February 07, 2017 May 54:04 PM Warmup: 1. f(x) = 5 x1 4 2. g(x) = 3(2) x+4 +1 a. Find the inverse of each function. b. Find the domain and range of the original function and inverse. c. Find the x and yintercepts of the original and inverse without graphing! May 39:56 AM Solving Logarithmic and Exponential Equations MGSE912.F.BF.5 Understand the inverse relationship between exponents and logarithms and use this relationship to solve problems involving logarithms and exponents. MGSE912.F.IF.8 Write a function defined by an expression in different but equivalent forms to reveal and explain different properties of the function. MGSE912.F.IF.8b Use the properties of exponents to interpret expressions for exponential functions.

Transcript of Solving Logarithmic and Exponential Equations · 2017-02-07 · 8 Notes Solving Logarithmic and...

Page 1: Solving Logarithmic and Exponential Equations · 2017-02-07 · 8 Notes Solving Logarithmic and Exponential Equations LB.notebook 1 February 07, 2017 May 54:04 PM Warmup: 1. f(x)

8 ­ Notes ­ Solving Logarithmic and Exponential Equations LB.notebook

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February 07, 2017

May 5­4:04 PM

Warm­up:1. f(x) = 5x­1  ­ 4 2. g(x) = ­3(2)x+4  + 1

a. Find the inverse of each function.

b. Find the domain and range of the original function and inverse.

c. Find the x and y­intercepts of the original and inverse without graphing!

May 3­9:56 AM

Solving Logarithmic and Exponential Equations

MGSE9­12.F.BF.5 Understand the inverse relationship between exponents and logarithms and use this relationship to solve problems involving logarithms and exponents. 

MGSE9­12.F.IF.8 Write a function defined by an expression in different but equivalent forms to reveal and explain different properties of the function. 

MGSE9­12.F.IF.8b Use the properties of exponents to interpret expressions for exponential functions. 

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February 07, 2017

May 5­4:01 PM

What am I learning today?

 How to use logarithmic properties to solve 

equations 

How will I show that I learned it?Solve equations using exponential and logarithmic 

operations and properties

Apr 29­9:16 AM

Properties of the Natural Logarithm

ln e = 1

ln 1 = 0

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February 07, 2017

May 5­4:09 PM

Solving Exponential Equations

Type 1: Powers of the same base

• Isolate the exponential part(s).

• Eliminate the base leaving only the     exponential part.                  • Always check your answers!!  

May 8 ­ 8:53 PM

1)  4 3x  =  8 x + 1

2)

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February 07, 2017

Mar 12­5:30 PM

Type 2: Bases are NOT powers of the same              base

• Isolate the exponential part(s).

• Apply a logarithm to each side. Use    change of base to help solve. 

• Always check your answers!!  

May 5­4:12 PM

3)  2x = 7

Solve for x.

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February 07, 2017

May 5­4:15 PM

4)  40 e0.6x + 20 = 240

May 5­4:16 PM

5)  2x = 3x ­ 1 (start on side with more difficult exponent)

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February 07, 2017

May 6­3:47 PM

Type 3:  Logs on each side have same base.

• Every term has loga(?). Condense until each   side has only one loga(?).

• Set the answers equal to each other.     Then solve.

• Always check your answers!! There are    extraneous situations 

May 5­4:23 PM

6)  log7(5x ­ 1) = log7(x + 7)

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February 07, 2017

May 3­9:57 AM

7)  ln x ­ ln 9 = ln 3

Apr 29­5:03 AM

8)

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February 07, 2017

Apr 29­5:32 AM

9)

May 6­3:47 PM

Type 4:  Log on only one side of the equation!

• Get logx(?) by itself on the one side.         Condense if necessary.

• Change the log equation to exponent form.    Then solve.

• Always check your answers!! There are    extraneous situations.  

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February 07, 2017

May 5­4:24 PM

10)  log5(3x + 1) = 2

May 5­4:28 PM

11)  log8(x ­ 3) + log8(x + 4) = 1

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February 07, 2017

Apr 29­5:36 AM

12)

Dec 5­4:59 PM

14)  9(123x ­ 5) ­ 75 = 1221Mixed Examples:

15)  log4x + log4(x2 ­ 3) = log43x

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February 07, 2017

May 6­3:49 PM

16)  ln x + ln (x ­ 5) = 1

4)     13216 2x + 1  = 

May 5­4:28 PM

5)  15 ­ 2log4(28x + 8) = 3

6)  5 x ­ 3 =  ­ 341

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February 07, 2017

May 5­7:32 PM

7)  log5(9x ­ 1) = log5(4x ­ 16)

8)  3 ln (­ x) + 9 = 20

May 5­7:35 PM

9)  102x ­ 3 + 4 = 21

10)  log6(x + 5) + log6x = 2

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February 07, 2017

May 5­7:35 PM

11) 3 + 5x = 21