Your Practice Set – Applications and Interpretation for IBDP Mathematics
4 . A quadratic function is given by
2 f ( x) ax bx c � � � . It is given that the complex roots of f( x) � 0 are
1 � � 2i and
2
1 � � 2i .
2
( a ) Write down the values of
( i )
( ii )
� 1 1 �� � 2i � �+ � �� � 2i �
� � 2 � � 2 � ;
� 1 1 �� � 2i �� ��� � 2i �
� � 2 �� 2 � . [ 2 ]
( b ) Hence , find the expression of f( x ), giving the answer in terms of a .
The graph of f( x ) passes through ( 0 , � 17 ) .
[ 3 ]
( c ) Find the value of a . [ 2 ]
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