2TH/vwo §1.2 Formulas for straight lines

• Wiskunde
• Middelbare school
• havo, vwo
• Leerjaar 2

Today:

§1.2 Formulas for straight lines

 om 21.22.41

Schermafbeelding 2021-07-28 om 21.23.01

You will also learn:

I'm afraid these goals will not make much sense yet,

so let's just start with an exercise!

First of all...

take before you:

- pencil, geo and eraser

- Textbook 2A p.14/15

- Notebook

Use the right materials for this task:

a pencil and geo triangle for drawing the table and a pen for the numbers!

Solution:

Now do 9b:

Again use the right stuff:

a pencil and a geo!

Then an important thing: what numbers to write on the horizontal axis

and what numbers on the vertical axis?!   For this study the table well! 

Solution:

Think about these questions and try to solve them:

Solutions  9c + 9d:

     After this, time for a joke!

Maybe you think:

y = 3.   has no gradient at all, so it cannot be 0 ?!

Still, it HAS a gradient, because you can also write it as:

y = 0x + 3

Because 0 times x = 0x = 0, you can leave this term out.

Task:

Make a linear formula for a Rising Graph.

So use this shape:

y = ax + b

(You have to find suitable numbers for a and b yourself.)

ANS

A formula for a rising graph:

Solution:

A rising graph, so the number for the letter a in

y = ax + b 

has to be positive!

For example:    y = 3x -6

The graph for y = 6 -4x
is a ....... graph.

1. rising
2. falling
3. horizontal
4. vertical

y = 6 -4x   has a 

Falling Graph, because of the number -4, that stands for 

the letter a in the general shape:

y = b + ax

( y = ax + b    and   y = b + ax  come down to the same thing!)

Homework:

As usual:

Havo, make the Support path

Vwo, do the Standard or Challenge path

ALL MAY SKIP:  9 and 10.

DRAW THE GRAPHS WITH A PENCIL AND A GEO TRIANGLE OR RULER!