Apps. and Interpretation for IBDP Maths Ebook 1 | Page 141

37
Paper 1 – Properties of Graphs
12
Example
The diagram below shows part of the graph of a function f .
The graph has a maximum at A(5, 4) and a minimum at B(3, � 2) .
The function f can be written in the form f ( x) � psin( qx)
� r . Find the value of
(a) p ;
(b) q ;
(c) r .
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Solution
(a)
4 �� ( 2)
p � (M1) for valid approach
2
p � 3
A1 N2
(b) The period of the graph is 4.
(c)
360
� � 4
(M1) for valid approach
q
q � 90
A1 N2
4 �( �2)
r � (M1) for valid approach
2
r � 1
A1 N2
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