Analysis and Approaches for IBDP Maths Ebook 2 | Page 68

Your Practice Set – Analysis and Approaches for IBDP Mathematics
20
Paper 1 Section A – Reciprocal Trigonometric Functions
Example
Given that
π
0 ��
� and
2
3
sin� � , find the value of cosec2� .
5
[4]
Solution
2
cos�
� 1�
sin �
�3
�
cos�
� 1� � �
�5
�
2
(A1) for substitution
4
cos� �
5
1
cosec2�
� (M1) for valid approach
sin 2�
1
cosec2�
�
2sin�cos�
1
cosec2 � � A1
� 3 �� 4 � 2� �� �
� 5 �� 5 �
25
cosec2� � A1
24
[4]
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