3Tvwo § 4.4 Choose the best Method! (1)

§ 4.4 Quadratic equations
Which method is the best for a specific exercise?
That's what we are going to find out now!

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Slide 1: Slide
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This lesson contains 17 slides, with interactive quizzes and text slides.

Items in this lesson

§ 4.4 Quadratic equations
Which method is the best for a specific exercise?
That's what we are going to find out now!

Slide 1 - Slide

Mention one Method for solving a Quadratic Equation.

Slide 2 - Mind map

SUMMARISING:
There are (at least) 5 Methods, that you learnt. In the next slide they come up.

Slide 3 - Slide

The 5 Methods
1.    using:   A x B = 0, then A=0 or B=0
2.   by:    Cards                                                       
3.   by:   Factorising   
4.   by:   Completing the square
5.   by:   the Quadratic Formula

Slide 4 - Slide

Slide 5 - Slide

Slide 6 - Slide

Choose the best Method for:
Solve 8(x - 7)(2x + 5) = 0
A
Cards
B
A x B = 0
C
Factorising
D
Completing the square

Slide 7 - Quiz

Once more 8(x-7)(2x + 5) = 0

A common mistake here is:
+  working out the brackets
+ making a few calculating mistake along the way
+ getting the wrong answer(s)
How to do it you see on the next slide!

Slide 8 - Slide

Solve 8(x - 7)(2x + 5) = 0
Only 2 steps I will show here:
divide by 8 on both sides of the = sign  :
(x -7)(2x + 5) = 0
Now use the scheme  A x B = 0,  so work out:
x - 7 = 0   or  2x + 5 = 0, etcetera!

Slide 9 - Slide

The same for:
Solve (x - 6)squared = 16
A
Completing the square
B
Quadratic Formula
C
Cards
D
A x B = 0

Slide 10 - Quiz

The same for:
Solve 3 a squared + 24a = 0
A
Quadratic Formula
B
A x B = 0
C
Completing the square
D
Factorising

Slide 11 - Quiz

The same for:
b squared + 6b + 5 = 13
A
A x B = 0
B
Factorising
C
Quadratic Formula
D
Completing the square

Slide 12 - Quiz

Once more b squared + 6b = 13
You can only see well how to solve it, after you have simplified the equation as follows:                       b squared + 6b - 13 = 0
Now you can see that there are no two numbers that are:
+  multiplied equal to -13  and
+ added up equal to + 6 
So this leads us to:  C Quadratic Formula, or also D Completing the square!

Slide 13 - Slide

The same with:
3 c squared - 5c + 2 = 0
A
Quadratic Formula
B
Factorising
C
A x B = 0
D
Cards

Slide 14 - Quiz

By the way .....
We just dealt with 5 Quadratic Equations, 
taken from:
Theory, p.131             
If you want to know how to work them out, 
Study this page!

Slide 15 - Slide

Do § 4.4 = Homework
A few notes on the content:
- in exercises 26, 27 and 28 you are 'taken by the hand' ;
so the Best Method is chose for you
- in 29 and 30 however, you will have to find the Best Method yourself!

Slide 16 - Slide

Work in silence for 10 minutes.
timer
10:00

Slide 17 - Slide