4-1 Linear formulas

• Wiskunde
• Middelbare school
• havo
• Leerjaar 3

Linear formulas

(p. 104)

What you need:

- Textbook, writingbook, iPad

- Pen, pencil, geotriangle

- Calculator

Schoolbags in the cuboard

Phones in the phonebag

Bluetooth 

- ON

- VPN off

Lesson goal

Identify linear formulas

Use the standard form for a linear relation y=ax+b

Linear relation

If the numbers in the top row are consecutive whole numbers, and there is a fixed increase per step in the bottom row, then there is a linear relation between the variables.

Is this a linear relation?

1. Yes
2. No

Is this a linear relation?

1. Yes
2. No

Which of these are linear relations?

1. 1
2. 2
3. 2 and 3
4. All of them

The formula for a linear function

y=ax+b

a is the gradient

b is the y intercept

GRADIENT

If the gradient is positive, 

the graph is increasing (uphill)

If the gradient is negative, the 

graph is decreasing (downhill)

If the gradient is 0, it is a horizontal line.

Parallel lines - same gradient

If two lines are parallel, they have the same gradient