# 2TH Ch 1 TOTALLY!

We are going on a trip. Get aboard!
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Slide 1: Tekstslide
WiskundeMiddelbare schoolvwoLeerjaar 1

In deze les zitten 38 slides, met interactieve quizzen en tekstslides.

Lesduur is: 50 min

## Onderdelen in deze les

We are going on a trip. Get aboard!

#### Slide 1 -Tekstslide

A trip through Book 2A VWO
Ch 1 Linear formulas!

#### Slide 2 -Tekstslide

Want to do well on the Test?
You can learn a lot!

#### Slide 3 -Tekstslide

A. Have a good look at this table. Is this a linear relation?
B. Answer the question on the following slide!

#### Slide 4 -Tekstslide

T IN SECONDS 0 10 20 40 50
HEIGHT IN M 30 45 60 90 105

A
Linear.
B
Directly proportional.
C
Linear nor directly proportional.
D
Both.

#### Slide 5 -Quizvraag

SOLUTION:
At first it seems  linear, but is it, really?
The height goes up by 15 m all the time.
However, the time goes up by 10 seconds, except for one time, when it goes up by 20. So it is linear, indeed!!

#### Slide 6 -Tekstslide

Choose right or wrong:
A
A linear formula is also directly proportional.
B
A linear formula is sometimes directly proportional.
C
A linear formula is never directly proportional.
D
Linear and directly proportional mean the same.

#### Slide 7 -Quizvraag

Directly proportional:
In the table you see that if x is
done times 2 then also y is done
times 2. Or both times 3; that works too!
The graph is a straight line that goes through the origin.
All this makes the relation between x and y directly proportional.

#### Slide 8 -Tekstslide

A directly proportional formula has no y-intercept.
A
True.
B
False.

#### Slide 9 -Quizvraag

Explanation:
A directly proportional formula has 0 as y-intercept!
For example:
y = -5x + 0, which is the same as
y = -5x, is a directly proportional formula.
The reason for this: the graph is a straight line, that goes through (0,0).

#### Slide 11 -Tekstslide

A
The formula is: H = 15T
B
The formula is: T = 1.5H
C
The formula is: H = 1.5T + 30
D
The formula is: 30 + 1.5H = T

#### Slide 12 -Quizvraag

Make a formula for the graph!

#### Slide 13 -Tekstslide

Choose the right formula:
A
y = 3x + 4
B
y=31x+4
C
y=31x+4
D
y = -3x + 4

#### Slide 14 -Quizvraag

Below you see the steps you have to take on the test, when making a formula is asked.

1. make a table:
2.  for every horizontal step the graph goes DOWN 3 steps,
3. the graphs intersects the y-axis at the height 4,  so the y-intercept is 4
4.  So: the formula is:   y = -3x + 4,  or    y = 4 - 3x, or:     -3x + 4 = y

#### Slide 15 -Tekstslide

Key in the formula that corresponds to this graph on the next slide.

#### Slide 16 -Tekstslide

What is the right formula?

#### Slide 17 -Open vraag

If x goes 3 steps to the right, then y goes up only 1 step.
So if x goes 1 step to the right, then y goes up
This means that the gradient is           The formula is:       y =     x -1
31
31
31

#### Slide 18 -Tekstslide

Next slide shows a mysterious drawing.

If you know who drew this, then key in the name of the artist.

#### Slide 20 -Tekstslide

The artist is ...

#### Slide 21 -Woordweb

His name is: Maurits Escher.
Here's another of his drawings,
or painting or .... whatever!

A
y = -8x + 1
B
y = 1/8 x + 1
C
y = 8x
D
y = 1/8 x - 1

#### Slide 23 -Quizvraag

Explanation formula:

1. make a table:
2. The gradient is 1/8, because in 1 horizontal step the graph goes up 1/8 grid
3. The y-intercept is -1 (read off)
4. Fill in the numbers 1/8 and -1 in the right places and you get:
y = 1/8 x - 1

#### Slide 24 -Tekstslide

The graph for y = -3 + 5x is
A
a straight horizontal line
B
a straight rising line
C
a vertical line
D
a straight falling line

#### Slide 25 -Quizvraag

Does (-12,-3) lie on the graph for
y = 2x + 21 ?
A
Yes, it does.
B
No, it does not.

#### Slide 26 -Quizvraag

Explanation:
Let us fill in (-12, -3) in y = 2x + 21.       As follows:
X = -12 and y = -3
The new equation becomes:
-3 = 2 x -12 + 21  Does this check out?
-3 = - 24 + 21
-3 = -3  Yes this checks out, so: (-12, -3) lies on the line!

#### Slide 27 -Tekstslide

Make a linear formula for a vertical line through point (-5, -7)
A
y = -7
B
x = -7
C
y = -5
D
x = -5

#### Slide 28 -Quizvraag

All points on the vertical line through (-5, -7)
have the same x coordinate:  -5.
That's why the formula is:
x = -5

#### Slide 29 -Tekstslide

Make a linear formula for a horizontal line through point (-5, -7)
A
x = -7
B
x = -5
C
y = -5
D
y = -7

#### Slide 30 -Quizvraag

All points through (-4, -7) have the same y coordinate:  -7
That's why the formula is:
y = -7

#### Slide 31 -Tekstslide

Mention something you've learnt this lesson.

#### Slide 32 -Woordweb

If you don't know enough about formulas for horizontal and vertical lines, then Study the Theories on p.15 and 16 from §1.2 closely:

#### Slide 33 -Tekstslide

Now the VERTICAL line's formula:

#### Slide 35 -Tekstslide

After all this.....
You will have learnt something for the coming test,
to say the least.

Homework time
Make p.36-38:
E1 t/m E8

#### Slide 37 -Tekstslide

That's all, folks!