� The discriminant
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� � � of
�� 0
�� 0
�� 0
b 4ac
2 ax bx c
� � � 0: The quadratic equation has two distinct real roots The quadratic equation has one double real root The quadratic equation has no real root
� The x -intercepts of the quadratic function corresponding quadratic equation
2 ax bx c
2 y � ax �bx � c are the roots of the � � � 0
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Functions
� The function y � f ( x)
: 1 . f( a ): Functional value when x� a
2 . Set of values of x : Domain 3 . Set of values of y : Range
� f g( x) � f ( g( x)) : Composite function when gx ( ) is substituted into f( x )
� |
�
Steps of finding the inverse function y
� f 1 ( x) of f( x ):
|
1 . |
Start from expressing y in terms of x |
2 . |
Interchange x and y |
3 . |
Make y the subject in terms of x |
�
� Properties of y � f 1 ( x) :
1 .
1 1 f ( f �
� ( x)) � f ( f ( x))
� x
�
2 . The graph of y � f 1 ( x) is the reflection of the graph of y � f ( x) about y� x www . seprodstore . com
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