Inequalities

32

Contents:

A Solving one variable inequalities with

technology [2.2]

B Linear inequality regions [7.7]

C Integer points in regions [7.7]

D Problem solving (Extension)

Opening problem

#endboxedheading

Some inequalities can be easily solved by examining a graph. For example:

² if we want to findxsuch that f(x)> 0 , we graphy=f(x) and find values ofxwhere the function

isabove thex-axis

SOLVING ONE VARIABLE INEQUALITIES

[2.2]

A

WITH TECHNOLOGY

Jason and Kate have set up a stall at the school fete. Their plan is to provide barbecued chops and

sausages for visitors at lunch time. Their butcher will sell them sausages for 40 cents each and chops for

$1: 00 each. Initially they think of what they could purchase for$20. Examine the following questions:

a Could they spend all the money buying chops?

If so, how many could they purchase?

b Could they spend all the money buying sausages?

If so, how many could they purchase?

c If they purchase 10 chops, how many sausages could they

purchase?

d Clearly these arethreesolutions to their problem, but are

there more? If so, how many more solutions are there and

how would we find them?

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Y:\HAESE\IGCSE01\IG01_32\639IGCSE01_32.CDR Monday, 27 October 2008 3:05:30 PM PETER