Your Practice Set – Applications and Interpretation for IBDP Mathematics
Exercise 1
1 . Let f ( x) �8x
� 1 and g x
2
( ) x 5 � � .
( a ) Find f
1 ( x) .
�
( b ) ( i ) Write down g ( 5 ) .
[ 3 ]
( ii ) Hence , find ( f g )( 5 ) . [ 3 ]
2 . Let f ( x) �2x
� 3 and g( x) ( x 5 )
2
� � .
( a ) Find f
1 ( x) .
�
( b ) ( i ) Write down f ( � 2 ) .
[ 3 ]
( ii ) Hence , find ( g f)( � 2 ) . [ 3 ]
3 . Let f ( x) � x � 4 , for x �� 4.
( a ) Find f � 1 ( 4 ) .
( b ) Let g be a function such that g( 96 ) � 7 and
1
g � exists for all real numbers .
[ 3 ]
( i ) Write down g � 1 ( 7 ) .
( ii ) Hence , find
1 ( f g � )( 7 ) .
[ 3 ]
4 . Let f ( x) � 2x � 1 , for
( a ) Find
f � 1 ( 3 ) .
1 x � .
2
( b ) Let g be a function such that
1
g �
�3a
�1� g � � � 2 , where a is a constant , find � 2 � of a . exists for all real numbers . Given that
[ 3 ]
1
( f g � )( 2 ) , give the answer in terms
[ 3 ]
4
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