3Tvwo §11A.2 / §11.B2 Exponential and square root equations

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• Middelbare school
• vwo
• Leerjaar 3

§11A.2 / §11.B2 Exponential and square root equations

Let's first deal with EXPONENTIAL EQUATIONS.

Square roots follow later.

The paragraphs for Math A and Math B again don't differ that much.

After this LessonUp choose the § that suits you best!

Task 1:

Question for all:       What makes it that:

+                                         is called an exponential equation, but

+                                         is not?

Think about this now. After 30 seconds thought:   Question for one of you:

' ..........., please open your mike and tell us your answer!'

2x​3​​=54

12⋅3​x​​=108

Solution 1:

In                                                      the variable is in the  exponent, so it is an

eponential equation,

but here:                                                   it's not!           

2x​3​​=54

12⋅3​x​​=108

Let's solve  Exponential equation nr.1 now:

                                                      we divide by 12 on both  sides

                                                      we write 108 as a power of 3 too

                x = 2                                      we find the solution

12⋅3​x​​=108

3​x​​=9

Exponential equation nr.2:

'One moment!'

, you might wonder:

'How am I supposed to know that 

                                ?!'

The next slide shows a useful tool for this!

81=3​4​​

a TABLE with powers of 3:

Do you remember we needed to write 81 as a power of 3?

Well make your choice in the store above:                         !

81=3​4​​

Task 2:

1. Open your Notebook.

2.Open your textbook on p.141(A) or p.1879(B)

3. Copy the following equation:          

4. Make a TABLE for powers of 2.

5. Solve the equation in the way of the Example on p.141(A) or p.179(B)

    (This was the content of a previous slide!)

5. You get 2 minutes for this task. Then key in your answer in the next slide.

Task 2 for one of you:

" ............, please open you mike -if you are at home!- and read out your final answer answer. So t = ..... .'

Solution task 2:

Notice how important the table is!

64 is the ..... power of 2? The 6th!

Still not quite clear what to do?

Here comes one more example!

We will solve:

First make a TABLE 

for powers of 4!

Solution:

The table tells us the 6th power of 4!

The last page of this paragraph is about:

SQUARE ROOT EQUATIONS.

TASK 3:     Pick out the SQUARE ROOT EQUATION(S) from:

A.                                                     C.

B.                                                      D.

Remember your choice for the next slide!

3√​6​​​=x​2​​

4√​t−5​​​=33

8p√​2​​​=64

√​6x−12​​​=7

SQUARE ROOT EQUATIONS ARE:

1. 8p root 2= 64
2. 3root 6 = x squared
3. 4root (t-5) = 33
4. root (6z - 12) = 7

How to SOLVE those

SQUARE ROOT EQUATIONS?

An example tells more!

Two examples tell even more!

Homework time.

Do and check with the Solutionsbook:     §11.A     or     §11.B now. 

You may skip p.140 (A)  or  p.178 (B), because we have done similar tasks.

Hand in your work on GoogleClassroom.