(1)计算(1+i2)2+5i3+4i(2)复数Z=x+yi(x,y∈R)满足Z+2i.Z=3+i,求点Z所在的象限.-数学

题目简介

(1)计算(1+i2)2+5i3+4i(2)复数Z=x+yi(x,y∈R)满足Z+2i.Z=3+i,求点Z所在的象限.-数学

题目详情

(1)计算(
1+i
2
)2+
5i
3+4i

(2)复数Z=x+yi(x,y∈R)满足Z+2i
.
Z
=3+i
,求点Z所在的象限.
题型:解答题难度:中档来源:不详

答案

(1)(class="stub"1+i
2
)2+class="stub"5i
3+4i

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

=i+class="stub"3
5
i+class="stub"4
5
=class="stub"4
5
+class="stub"8
5
i

(2)把z=x+yi代入z+2i
.
z
=3+i,
得x+yi+2i(x-yi)=3+i
所以(x+2y)+(2x+y)i=3+i
x+2y=3
2x+y=1
,解得
x=-class="stub"1
3
y=class="stub"5
3

所以复数z对应的点在第二象限.

更多内容推荐