Analysis and Approaches for IBDP Maths Ebook 2 | Page 114

Your Practice Set – Analysis and Approaches for IBDP Mathematics
34
Paper 1 Section A – Argand Diagrams
Example
In the following Argand diagram with the origin O , the point A represents the complex
number �4 � 10i . The shape of OABC is a square.
(a) Determine the complex numbers represented by the points B and C .
(b) Hence, find the area of OABC .
[4]
[2]
Solution
(a) zB
� �4 �10i � (10 � 4i)
M1
(b)
z �6 � 14i
B
z � 0 � 0i � (10 � 4i)
M1
C
z �10 � 4i
C
Thus, the complex numbers represented by the
points B and C are 6 � 14i and 10 � 4i
respectively.
The area of OABC
A2
2
� (OA)
M1
2 2 2
� ( ( �4) � 10 )
� 116
A1
[4]
[2]
104
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