题目内容
已知复数z满足:|z|=1+3i-z,(1)求z并求其在复平面上对应的点的坐标;
(2)求
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101225948411507328/SYS201311012259484115073014_ST/0.png)
【答案】分析:(1)设z=x+yi(x,y∈R),则|z|=
.代入已知,化简计算,根据复数相等的概念列出关于x,y的方程组,并解出x,y,可得z.
(2)将(1)求得的z代入,化简计算后,根据共轭复数 的概念求解.
解答:解:(1)设z=x+yi(x,y∈R),则由已知,
=1+3i-(x+yi)=(1-x)+(3-y)i.
∴
,∴z=-4+3i.
其在复平面上对应的点的坐标为(-4,3).
(2)由(1)z=-4+3i,
∴
=
=
=
=
=3+4i
共轭复数为3-4i.
点评:本题考查复数代数形式的混合运算,复数模、共轭复数求解. 除法的运算中,关键是分子分母同乘以分母的共轭复数,实现分母实数化.
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101225948411507328/SYS201311012259484115073014_DA/0.png)
(2)将(1)求得的z代入,化简计算后,根据共轭复数 的概念求解.
解答:解:(1)设z=x+yi(x,y∈R),则由已知,
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101225948411507328/SYS201311012259484115073014_DA/1.png)
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101225948411507328/SYS201311012259484115073014_DA/2.png)
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101225948411507328/SYS201311012259484115073014_DA/3.png)
其在复平面上对应的点的坐标为(-4,3).
(2)由(1)z=-4+3i,
∴
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101225948411507328/SYS201311012259484115073014_DA/4.png)
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101225948411507328/SYS201311012259484115073014_DA/5.png)
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101225948411507328/SYS201311012259484115073014_DA/6.png)
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101225948411507328/SYS201311012259484115073014_DA/7.png)
![](http://thumb.zyjl.cn/pic6/res/gzsx/web/STSource/20131101225948411507328/SYS201311012259484115073014_DA/8.png)
共轭复数为3-4i.
点评:本题考查复数代数形式的混合运算,复数模、共轭复数求解. 除法的运算中,关键是分子分母同乘以分母的共轭复数,实现分母实数化.
![](http://thumb.zyjl.cn/images/loading.gif)
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