Apps. and Interpretation for IBDP Maths Ebook 1 | Page 150

Your Practice Set – Applications and Interpretation for IBDP Mathematics
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Paper 2 – Applications in Daily Lives
Example
At a beach the height of the water in metres is modelled by the function
h( t) � pcos( qt)
� r , where t is the number of hours after 20:00 hours on 1 March 2018,
for 0 �t
� 60 .
The point A (6, 0.8) represents the first low tide and B (12, 2) represents the next high
tide.
(a) (i) How much time is there between the first low tide and the next high
tide?
(b)
(ii)
Find the difference in height between low tide and high tide.
Find the value of
[4]
(i) p ;
(ii) q ;
(c)
(iii) r .
[7]
There are two low tides on 3 March 2018. At what time does the second low tide
occur?
[3]
Solution
(a) (i) The amount of time
�12 � 6
(M1) for valid approach
� 6 hours A1 N2
(ii)
The difference
�2� 0.8
(M1) for valid approach
� 1.2 m A1 N2
[4]
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