1718 WB1Y CH1 (book 2A) Lesson 1

• Wiskunde
• Middelbare school
• vwo
• Leerjaar 1

Which of these formulas is a
LINEAR formula?

1. y=x​2​​+2x
2. y=x​3​​
3. y=0.2x−3
4. y=2x​2​​−0.5x​3​​

Which of these formulas is a
QUADRATIC formula?

1. y=x​2​​+2x
2. y=x​3​​
3. y=0.2x−3
4. y=2x​2​​−0.5x​3​​

Recap: plotting a LINEAR graph

1) Make a table

Top row = Value you fill in = Horizontal axis

Bottom row = Value you calculate = Vertical axis

2) Draw a coordinate system

Use a pencil and geotriangle, use an appropriate scale for each axis, label your axes, use a zigzag if needed

3) Plot the graph

Use a pencil, plot the points, connect with a straight line.

Example

Plot the graph for the formula                               , take x from -5 to 5.

1) Make a table

y=0.3x−50

Example

Plot the graph for the formula                               , take x from -5 to 5.

1) Make a table

y=0.3x−50

Example

Plot the graph for the formula                               , take x from -5 to 5.

2) Draw a coordinate system

Horizontal axis from -5 to 5, steps of 1.

Vertical axis from -51.5 to -48.5, zigzag and steps of 0.2 or 0.5.

y=0.3x−50

3) Plot the graph                                   Plot the points from the table.

3) Plot the graph

Connect with a straight line.

Recap: plotting a PARABOLA

1) Make a table

Top row = Value you fill in = Horizontal axis

Bottom row = Value you calculate = Vertical axis

2) Draw a coordinate system

Use a pencil and geotriangle, use an appropriate scale for each axis, label your axes, use a zigzag if needed

3) Plot the graph

Use a pencil, plot the points, connect with a smooth curve.

Example

Plot the graph for the formula                               , take x from -5 to 5.

1) Make a table

y=0.5x​2​​+x

Example

Plot the graph for the formula                               , take x from -5 to 5.

1) Make a table

y=0.5x​2​​+x

Remember:

Use brackets when squaring a negative variable!

Example

Plot the graph for the formula                               , take x from -5 to 5.

2) Draw a coordinate system

Horizontal axis from -5 to 5, steps of 1.
Vertical axis from -0.5 to 17.5, steps of 1 or 2.

y=0.5x​2​​+x

3) Plot the graph                                   Plot the points from the table.

3) Plot the graph

Connect with a smooth curve.

Solve the equation
3a - 10 = 26

Recap: solving equations with cards

3a - 10 = 26

3a = 36                            (because 36 - 10 = 26)

a = 12                                (because 3 x 12 = 36)

Homework Tuesday

Make and correct

R1, R2, R3, R4, R5, R6, R7, R8

from CH1 Linear Formulas in book 2A