2Tvwo §9.4 Solving inequalities (2)

§9.4 Solving inequalities

(ongelijkheden)

Up to now we only dealt with equations, so:

'something being equal to something else'.

However,

something could also be greater than or smaller than something else!

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WiskundeMiddelbare schoolvwoLeerjaar 2

This lesson contains 24 slides, with text slides.

Lesson duration is: 50 min

Items in this lesson

§9.4 Solving inequalities

(ongelijkheden)

Up to now we only dealt with equations, so:

'something being equal to something else'.

However,

something could also be greater than or smaller than something else!

Slide 1 - Slide

Below you see what you will learn and the kind of tasks

you are going to solve. But how?!

Do you remember the signs:

for 'smaller than' and

for 'greater than'?

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A balance or a graph...

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Next slide ....

Shows the MEANING of the process of solving an equation.

You get a good idea for what situations it could be used.

Only after that we will watch every little step!

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As you can see in the graphs,

for 30 minutes the water level is the same in A and B.

Task 'e' asks us for which VALUES (so more than one!) of t graph A is HIGHER then graph B

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Finally here comes the METHOD how to

SOLVE an INEQUALITY (ongelijkheid).

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SOLVING INEQUALITIES:

We don't have graphs (yet), but just an INEQUALITY!

In order to SOLVE this,

we will make a SKETCH of the two graphs ourselves.

Next slides show how to do all this!

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The following slide shows you an example of this METHOD!

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Practicing solving inequalities!

Now you get a complete example from me to watch and try to understand.

After all this it will be much easier for you to do §9.4 Solving inequalities!

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Let's do c now.

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step 1: make an equation:

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step 2: solve this equation:

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step 3: sketch the 2 graphs:

Extra (not really needed):

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step 4: Read off the solution from the inequality:

Solution:

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After all is said and done ...

There are exercises 29, 30 and 31 to be done by yourself.

In 29 and 30 no graphs are given, so just

+ work out the 4 points from the Method on p.102, we just went through

+ making sketches of both graphs, etc.

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Homework time

DO:

§9.4: 29, 30 and 31

CHECK your WORK with the SOLUTIONS BOOK and

SEND in a few PICS in GC

Looking forward to your work!

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