Z∈C,满足Z+1Z∈R,Z-14是纯虚数,求Z.-数学

题目简介

Z∈C,满足Z+1Z∈R,Z-14是纯虚数,求Z.-数学

题目详情

Z∈C,满足Z+
1
Z
∈R
Z-
1
4
是纯虚数,求Z.
题型:解答题难度:中档来源:不详

答案

设z=a+bi(a∈R,b∈R)
Z-class="stub"1
4
=(a-class="stub"1
4
)+bi
Z-class="stub"1
4
是纯虚数
∴a-class="stub"1
4
=0,b≠0
∴a=class="stub"1
4
,b≠0①
Z+class="stub"1
Z
=a+class="stub"a
a2+b2
+(b-class="stub"b
a2+b2
)i
∈R
b-class="stub"b
a2+b2
=0
∵b≠0
∴a2+b2=1②
∴由①②得b=
+
.
3
2

∴Z=class="stub"1
4
+
3
2
i或Z=class="stub"1
4
-
3
2
i

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