Analysis and Approaches for IBDP Maths Ebook 1 | Page 158

Your Practice Set – Analysis and Approaches for IBDP Mathematics
Exercise 52
2x
1. Let f( x)
��
2
x �5x�4
for �4� x � 7, x � 1, x � 4
. The graph of f is given below.
The graph of f has a local minimum at A(2, 2) and a local maximum at B .
2
2( x � 4)
(a) Use the quotient rule to show that f�( x)
�
.
2 2
( x �5x�4)
[6]
(b) Hence find the coordinates of B .
[7]
(c) Given that the line y� k does not meet the graph of f , find the possible values
of k .
[3]
6x
� 24
2. Let f( x)
�
2
x � 3x
for �8� x � 4, x �� 3, x � 0
. The graph of f is given below.
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