1TH/vwo §8.5 Powers of negative numbers

• Wiskunde
• Middelbare school
• havo, vwo
• Leerjaar 1

To understand §8.5 better, we first shortly look back at 

POWERS.

Because .... what are powers again?!

Powers were explained earlier this year, in §7.2

Let's repeat that explanation first!

5​3​​=....

1. 125
2. 15
3. 625

Task 1:

Key in your answer in the next slide!

Who's right about: the square of -3 ?
Paulo says: 9
Sabine says: -9

1. Sabine
2. both
3. Paulo
4. neither

explanation:

Task 2:

-           = 25      A

-           = - 25   B

-           = 10       C

-           = - 10    D    Fill in the good answer in the next slide.

5​2​​

5​2​​

5​2​​

5​2​​

= ...

−5​2​​

1. 25
2. - 25
3. 10
4. - 10

explanation:

-         =    -  5 x 5 = - 25

So the key to the answer is that only 5 is squared, but not

the minus sign!!

Next is the ORDER of OPERATIONS (volgorde van bewerkingen).

5​2​​

After this short REFRESH, we are in §8.5 now.

After all this squaring ......

+ we'll deal with higher powers too!

Task : 

in the same way do:

=  ............

Key in your answer in the next slide.

−4​3​​

Task :

(−4)​3​​

1. 64
2. -64
3. -12
4. 12

Explanation Task :

=  -4 x -4 x -4 = -64

(−4)​3​​

Further Explanation Task : 

=   -   4 x 4 x 4 = -64

                        = -4 x -4 x -4 = -64                       

So, do             and                    give the same outcome?!

Indeed, they do!!        

−4​3​​

(−4)​3​​

−4​3​​

(−4)​3​​

Let's study a few more difficult tasks together.

For this it is important to work it out on paper,

just like on a test!

Open your NOTEBOOK en

GET a PEN, please.

COPY and MAKE in your NOTEBOOK:

This is the Solution:

TASK 6:

this is a Fotovraag:

MAKE THIS ONE IN YOUR NOTEBOOK: FIRST COPY the TASK!

Then WORK IT OUT, TAKE A PICTURE AND SEND IT IN IN NEXT SLIDE.

TASK 6:

EXPLANATION TASK 6:

HOMEWORK (preparing for next Fridays test about Ch8+9)

Make:

p.68/69 Mixed exercises:

+ exercises 48 and 50  and

   CHOOSE 3 of the remaining exercises (preferably the ones you are

   not that good at, yet).

+  a little ADVISE on the homework follows.

The exercises e. t/m. h contain more than one

operation.

Work it out completely in your NOTEBOOK!

Not just the answer. Also see next slide!

HOMEWORK TIME 

H/V:       41 t/m 45

VWO:     42 t/m 46

As you can see, for 45 and 46 the CALCULATIONS are of the greatest importance!

So, when making them, don't just give the answers but show 

all the steps it takes, to get the answer!