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..HELPME...HELLO.IAMASTUDENTOFINTERNATIONALSCHOOL.ICAN'TUNDERSTAND.PLEASEHELPME...THX..1.已知|1-4ki|=5,求实数k的值.2.已知复数z=|2-3i|+3i,求|z|

题目详情
..HELP ME ...
HELLO.I AM A STUDENT OF INTERNATIONAL SCHOOL.I CAN'T UNDERSTAND.PLEASE HELP ME...THX..
1.已知 |1-4ki|=5,求实数k的值.
2.已知复数 z=|2-3i| + 3i ,求|z|
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答案和解析
Now,let me help you,My english is too bad,Can you help me?
haha(中文~!)
first
|1-4ki|=5
1^2+16k^2=25
16k^2=24
k^2=24/16
k=(+ or -)2根号6/4
second
z=|2-3i| + 3i
=根号13+3i
so |z|=根号(13+9)=根号22