1TH/Vwo §6.5 Comparing graphs

§6.5 Comparing graphs
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Slide 1: Slide
WiskundeMiddelbare schoolhavo, vwoLeerjaar 1

This lesson contains 31 slides, with interactive quizzes and text slides.

time-iconLesson duration is: 50 min

Items in this lesson

§6.5 Comparing graphs

Slide 1 - Slide

Good morning!

Slide 2 - Slide

Good morning, everybody!

Slide 3 - Slide

Slide 4 - Slide

Let's go through an exercise!

Slide 5 - Slide

This graph shows you
 the cost when
 hiring a lawn mower

Slide 6 - Slide

Because 2 graphs are drawn in 1
coordinate system,
we can COMPARE them!

Slide 7 - Slide

Task 1:
After how many days is the price 
you pay at Praxis 
the same as at Finefix?
Key in in next slide.

Slide 8 - Slide

Task 1:
After how many days is the price
you pay at Praxis
the same as at Finefix?
Key in your answer.

Slide 9 - Open question

Task 1:
So for 4 days the prices are equal. Both
companies then charge 50 euros.
We call the point (4, 50)
the Point of Intersection (= snijpunt)!

Slide 10 - Slide

Task 2:
If you hire a lawn mower
 for 2 days, which company is 
Answer in next slide.

Slide 11 - Slide

For 2 days ....
better choose for Praxis
it depends
better choose for Finefix
doesn't matter

Slide 12 - Quiz

Explanation exercise ,
Task 2:
If you hire a lawn mower for 2 days, what is 
the cheapest?
1. Go to '2 days' on the horizontal axis.
2. Go up and see which graph is highest.
3. Well, Finefix' graph lies lower,
4. so Finefix is cheapest for 2 days!

Slide 13 - Slide

Slide 14 - Slide

Task 3:
If you hire a lawn mower for 5 days,
which company is cheapest then?
Key in in next slide.

Slide 15 - Slide

For 5 days ...
Praxis is cheapest.
Doesn't matter.
Finefix is cheapest.

Slide 16 - Quiz

Explanation exercise 32,
Task 3:
If you hire a lawn mower for 5 days,
which company, which is cheapest?
Go to 5 days on the horizontal axis.
Go up and see which graph lies lowest.
Praxis' graph is lowest for 5 days,
so then the price is lowest too! 

Slide 17 - Slide

Task 4:
Which graph has a fixed amount?
(That is the amount you have to pay, 
no matter how many days they will work
for you!)

Slide 18 - Slide

A fixed amount ...
Graph for Praxis has one.
No clue at all.
Graph for Finefix has one.
Both graphs have one.

Slide 19 - Quiz

Explanation exercise ,
Task 4:
Which graph has a fixed amount?
The graph for Praxis starts at 10 euros.
That's what you have to pay before you have used 
this carpet cleaner for even one minute!
That's why we call this a FIXED AMOUNT.
The amount is fixed, no matter how long you use it. 

Slide 20 - Slide

Question: What to do first, when making this task ?

Slide 21 - Slide

First you have to ....

Slide 22 - Mind map

Make a TABLE, indeed!
In exercises 33a. and  34a  they ask you to make a graph from a formula.
Also for those tasks MAKE a TABLE first!
How else do you know which points lie on the graph?!
However, a TIP for this follows now.

Slide 23 - Slide

This is how the
However, why including so may points in the TABLE?
They all lie on the same straight line!
So 3 or 4 points will be enough. For example number 0, 10 and 16.

Slide 24 - Slide

The two graphs have a point
of intersection.
I read off:   (5, 3.5) is the p.o.i.
However, it is NOT a grid point, so I cannot be sure.
Fortunately I can also CALCULATE the coordinates!      

Slide 25 - Slide

If you have no clue what is meant here,
watch the following slides! You will see:
- two graphs that have a point of intersection
   that you can READ OFF
- after this the FIRST COORDINATE will be FILLED in in
   both FORMULAS, to see if we get THE SAME ANSWER!

Slide 26 - Slide

Slide 27 - Slide

Slide 28 - Slide

In this lessonup you have learned .....
I'd much better ASK YOU, what you've learned!
Think of a 'general description' (=algemene beschrijving) for what you learned.

Slide 29 - Slide

I have learnt ...

Slide 30 - Mind map

Homework time
Make §6.5. You may skip 30.
- correct with Solutionsbook

Slide 31 - Slide