Apps. and Interpretation for IBDP Maths Ebook 2 | страница 333

Answers
Exercise 18
18.1
( a )
ABC ˆ �
65.8 or 114
( b )
ACB ˆ �
45.8
18.2
( a )
BAC ˆ �
62.4 or 118
( b )
AB �
22.5 or 11.1
( c )
11.4
18.3
( a )
ABC ˆ �
42.6 or 137
( b )
6.96
18.4
( a )
BAC ˆ �
64.0 or 116
( b )
( i )
AB �
20
( ii )
80.1
Chapter 6
Exercise 19
19.1 ( a )
1 3 4
� � i 3� 4i 25 25
( b )
2 7
24 z � �
� i 625
625
( c )
7
�
625
19.2
( a )
z �1� 2i
( b )
�
2
19.3
( a )
z
�3�
4i
( b )
4 z � �527 �
336i
( c )
�
527
19.4
( a )
z � �323
� 36i
( b )
3 2
( i z) � �103033 � 23256i ( c ) � 23256
Exercise 20
20.2
( a )
2 476
480 z � �
� i 169
169
( b )
4
( c )
�
2.35 rad
20.3 ( a ) ( i )
( ii )
( b )
936
125
( c )
� rad
2
20.4 ( a ) z1 � 2
3 352 936 z � � � i
125 125
3 * 352 936 ( z ) � � i
125 125
( b )
a �
3
( c )
2
2� arg ( z2 ) �� rad
3
Exercise 21
21.1
( a )
( i )
5
( ii )
�
12
( b )
13
( c )
338
21.2
( a )
( i )
2
� 10i
( ii ) �8 � ( 10 � 10 3 ) i
( b )
173
21.3
( a )
Refer to solution
( b )
3� arg ( �) � rad
4
( c )
36
21.4
( a )
Refer to solution
( b )
5� arg ( �) � rad
4
( c )
202.5
20.1
( a )
3
4 z �
� i 5
5
( b )
1
( c )
�
0.927 rad
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323