设i为虚数单位,则5-i1+i=()A.-2-3iB.-2+3iC.2-3iD.2+3i-数学

题目简介

设i为虚数单位,则5-i1+i=()A.-2-3iB.-2+3iC.2-3iD.2+3i-数学

题目详情

设i为虚数单位,则
5-i
1+i
=(  )
A.-2-3iB.-2+3iC.2-3iD.2+3i
题型:单选题难度:中档来源:浙江

答案

class="stub"5-i
1+i
=
(5-i)(1-i)
(1+i)(1-i)
=class="stub"4-6i
2
=2-3i

故选C.

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