若z1=a+3i,z2=3+4i,且z1z2为纯虚数,则实数a=______.-数学

题目简介

若z1=a+3i,z2=3+4i,且z1z2为纯虚数,则实数a=______.-数学

题目详情

若z1=a+3i,z2=3+4i,且
z1
z2
为纯虚数,则实数a=______.
题型:填空题难度:中档来源:包头三模

答案

z1
z2
=class="stub"a+3i
3+4i
=
(a+3i)(3-4i)
(3+4i)(3-4i)
=
(3a+12)+(9-4a)i
25
,∴
3a+12=0
9-4a≠0
解得a=-4
故答案为:-4

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