Quadratic equations

• Wiskunde
• Middelbare school
• vwo
• Leerjaar 3

Quadratic graphing

You need your Ipad, notebook, calculator

Give the equation of this graph

Give the equation of the graph

Give the equation of this graph

Today

• Start lesson (10 min)
• 'New' subject (20 min)
• Work in Bettermarks (20 min)
• Question together (15 min)
• Work in Bettermarks (15 min)

How do we call curved graphs?

Give the coördinates of the vertex of the graph

Give the coördinates of the vertex

Give the coördinates of the vertex of the graph

Give the equation of the axis of symmetry

Give the equation of the axis of symmetry

Give the equation of the axis of symmetry

Give the coördinates of the zeroes in this parabola

Quadratic graphing

A curved graph is called a parabola.

Vertex: The lowest (or highest) point of the parabola

Axis of symmetry: The line passing through the vertex.

Zeroes: Where the parabola intersects the x-axis.

Quadratic graphing

Quadratic formula:

Axis of symmetry:

y=ax​2​​+bx+c

x=​2a​​−b​​

Quadratic formula

y=ax​2​​+bx+c

Geogebra

Bettermarks

• 20 minutes
• Bettermarks 12.1 and 12.2
• Raise your finger if you have any questions or when you're finished
• Communicate in English please

Quadratic formula

x	-2,5	-2	-1,5	-1	-0,5	0	0,5	1	1,5	2
y

y=2x​2​​+4x−3

Quadratic formula

x	-2,5	-2	-1,5	-1	-0,5	0	0,5	1	1,5	2
y

y=2x​2​​+4x−3

y=2⋅(−1.5)​2​​+4⋅−1.5−3

Quadratic formula

x	-2,5	-2	-1,5	-1	-0,5	0	0,5	1	1,5	2
y

y=2x​2​​+4x−3

y=2⋅(−1.5)​2​​+4⋅−1.5−3

y=−4.5

Quadratic formula

x	-2,5	-2	-1,5	-1	-0,5	0	0,5	1	1,5	2
y			-4,5

y=2x​2​​+4x−3

y=2⋅(−1.5)​2​​+4⋅−1.5−3

y=−4.5

Finding the axis of symmetry

f(x)=x​2​​+3x−2