Solving inequalities and graphing
Example Solve and graph 2 | x + 2 | > 6
Solution : i) Isolate the absolute value as | x + 2 | > 3
ii) Setting the contents of the absolute value portion to + 3 and - 3 or
+ (x + 2) > 3 and - ( x + 2) > 3
\ x + 2 > 3 and x+2 < -3
x > 1 and x < -5
The graph is
Example Solve and graph | 2 x - 1 | £ 5
Solution : | 2 x - 1 | £ 5
Therefore, setting the contents pf the absolute value portion as
( 2 x - 1 ) £ + 5 and - ( 2 x - 1) £ + 5
\ 2 x £ 6 and 2 x ³ - 5
\ x £ 3 and 2 x ³ - 4
x ³ - 2
\ x £ 3 and x ³ -2 or - 2 £ x
Therefore , - 2 £ x £ 3 . . . required solution
= [ - 2 , 3 ]
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Index
7.1 Definition 7.2
Simultaneous Equations 7.3
Inequations (Inequalities) 7.4
Absolute Values
Chapter 8
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