问题 解答题
(1)已知z1=5+10i,z2=3-4i,
1
z
=
1
z1
+
1
z2
,求z.
(2)已知(1+2i)
.
z
=4+3i,求z及
z
.
z
答案

(1)∵

1
z1
=
1
5+10i
=
5-10i
(5+10i)(5-10i)
=
1-2i
25
1
z2
=
1
3-4i
=
3+4i
25

1
z1
+
1
z2
=
4+2i
25

故z=

25
4+2i
=
25(4-2i)
20
=5-
5
2
i.

(2)∵

.
z
=
4+3i
1+2i
=
10-5i
5
=2-i,

∴z=2+i,

z
.
z
=
2+i
2-i
=
3+4i
5

单项选择题
单项选择题 A1型题