Logarithms part 1

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• Middelbare school
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• Leerjaar 4

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Lesopbouw:

1. VOORAF: Startklaar, Voorkennis activeren, Formatief Handelen
2. INSTRUCTIE: Leerdoelgericht werken, Inclusieve didactiek, Concrete en herkenbare voorbeelden, Formatief Handelen
3. TOEPASSING: Actieve verwerking, Formatief handelen 
4. EVALUATIE: Afsluiting

Today

- Recap: Transformations of Explonantional Functions

- New theory: logarithms

Discuss Worksheet 2.6

Learning goals

- You can solve exponential equations

- You know what a logarithmic function is

- You can solve logarithmic equations

Learning goals

- You can solve exponential equations

- You know what a logarithmic function is

- You can solve logarithmic equations

Exercise

Show that                  can be derived to 

Which rules for exponents do you use?

Example

Write the formula                                 in the form                   

Exercise 

Write the formulas in the form                   

a)

b)

c)  

Solving exponential equations: example

Use: gA = gB gives A = B                   

example:

Exercise

Recap last lesson

- You can solve exponential equations

Recap last lesson

- You can solve exponential equations

Discuss homework / practice more

No questions on the homework? Work on additional exercises (worksheet 2.8 exercise 1)

Learning goals

- You can solve exponential equations

- You know what a logarithm(ic function) is

- You can solve logarithmic equations

So... What do we actually do?

... when solving this: 

2x = 16 ?

So... What do we actually do?

... when solving this: 

2x = 16 ?

Basically, we ask: "2 raised to which power equals 16?" 

This is expressed as log2(16) = 4 ("log base two of sixteen is four") 

Logarithmic and exponential form

\

 

Definition

Which of the following is equal to
?

Which of the following is equal to
?

Write log_2(64) = 6 in exponential form

Write log_4(16) = 2 in exponential form.

Exercise: calculate exact

Worksheet 2.7

Need more challenging exercises? Make also  exercise 2 (worksheet 2.8)