Apps. and Interpretation for IBDP Maths Ebook 1 | Page 380

Your Practice Set – Applications and Interpretation for IBDP Mathematics
56.3 (a) (i) y � 5
(ii) y � 2
(b) x � 3 or x � 11
(c) (11, 2)
(d) f (9)
56.4 (a) (i) y � 0
(ii) y � 12
(b) x �� 4, 1�x
� 5 or x � 5
(c) (1, 20)
(d) f (2)
Exercise 57
57.1 (a)
54
C�( x) �2x
�
2
x
(b) 3 kg
(c) $33
57.2 (a) 1000
(b)
2
P�( t) � 3t � 24t
� 36
(c) 2
(d) 32001000
57.3 (a) t � 2.12 or t � 4.10
(b)
216
Q�( t) �8t
�
2
t
(c) t � 3
57.4 (a)
P� t � � t � t �
2
( ) 3 18 24
(b) t � 2
(c) The minimum price of the
share is $700, which is
greater than $690
Exercise 58
58.1 (a) r �� 29
(b)
(c) (4, 79)
f � x � � x � x �
2
( ) 3 6 24
(d) x �� 2 or x � 4
(e) (i) � 1
(ii) f �(0) � 24
(iii) 24x� y�1�
0
(iv)
58.2 (a) r �� 5
(b)
1
x �
24
f � x � x �
(c) (5, � 650)
2
( ) 6 150
(d) x �� 5 or x � 5
(e) (i) � 2
(ii) f �( �1) � � 144
(iii)
1
144
(iv)
1 287
y� x�
144 144
(v) x � 287
58.3 (a) x � 0
(b)
64
f�( x) �125
�
3
x
(c) (0.8,150)
(d) 0 �x
� 0.8
(e) (i) 157
(ii) f �(1) � 61
(iii) 61x� y�96 � 0
(f) y � 150
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