# 2Tvwo §5.4 Quadratic formulas 2!

§ 5.4 Quadratic formulas
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Slide 1: Slide
WiskundeMiddelbare schoolhavo, vwoLeerjaar 2

This lesson contains 17 slides, with interactive quiz and text slides.

Lesson duration is: 50 min

## Items in this lesson

§ 5.4 Quadratic formulas

#### Slide 1 -Slide

Removing brackets
§5.4 and §5.5 do NOT require you to remove brackets and write formulas shorter. To keep up with your skill in removing brackets, try to regularly make some exercises from tinyurl.com/removing brackets:

lvl (= level) 3, 4 and 5: single brackets (§5.1)
lvl 6, 7 and 8: double brackets (§5.2)
lvl 9: writing formulas with not only brackets shorter (§5.3)

#### Slide 2 -Slide

is a quadratic formula (it has a variable squared)

If we want to plot the graph of this formula, we should first make a table. Take the horizontal axis from -3 to 7.
y=2x28x

#### Slide 3 -Slide

Filling in a quadratic formula

#### Slide 4 -Slide

Filling in a quadratic formula

#### Slide 5 -Slide

Plotting the graph for a quadratic formula

This table shows us we should take:
- the horizontal axis from -3 to 7 (with steps of 1)
- the vertical axis from - 10 to 45 (with steps of 5)

#### Slide 6 -Slide

Plotting the graph for a quadratic formula

#### Slide 7 -Slide

Plotting the graph for a quadratic formula

Plot all points from the table

#### Slide 8 -Slide

Plotting the graph for a quadratic formula

Plot all points from the table
Connect with a smooth curve
Now a Math Joke!

#### Slide 10 -Slide

Upward or downward opening parabola
Graphs for a quadratic formula are
called parabolas
This parabola is an
upward opening parabola.

#### Slide 11 -Slide

Upward or downward opening parabola
In the coordinate system on the
right, the green graphs are
upward opening parabolas
and the purple graphs are
downward opening parabolas.

#### Slide 12 -Slide

Upward or downward opening parabola
You will find that you can tell from the formula if a parabola is upward or downward opening.

If the number in front of
is positive, it is upward opening
If the number in front of
is negative, it is downward opening.
x2
x2

#### Slide 13 -Slide

Vertex
The lowest point in an
upward opening parabola,
or the highest point in a
downward opening parabola
is called the vertex.

#### Slide 14 -Slide

Axis of symmetry
All parabolas have
reflection symmetry.
The vertical line through
the vertex is the axis of symmetry

All vertical lines have a formula
x = ....

#### Slide 15 -Slide

HOMEWORK
Make and correct §5.4

(suggestion: practice removing brackets again on tinyurl.com/removingbrackets, lvl 3-9)
lvl = level

#### Slide 16 -Slide

What did you learn this lesson?