3若复数4-3a-a2i与复数a2+4ai相等,则实数a的值为( )
A.1 B.1或-4
C.-4 D.0或-4
解析:由复数相等的充要条件,有{■(4"-" 3a=a^2 "," @"-" a^2=4a"," )┤
解得a=-4.
答案:C
4已知复数z=m2-m+(m2-1)i(m∈R).若z是实数,则m的值为 ;若z是虚数,则m的取值范围是 ;若z是纯虚数,则m的值为 .
解析:复数z=m2-m+(m2-1)i的实部为m2-m,虚部为m2-1.
当m2-1=0,即m=±1时,z为实数;
当m2-1≠0,即m≠±1时,z为虚数;
当m2-m=0,且m2-1≠0,即m=0时,z为纯虚数.
答案:±1 m≠±1 0
5适合x-3i=(8x-y)i的实数x,y的值分别是 .
解析:由复数相等的充要条件,得{■(x=0"," @"-" 3=8x"-" y"," )┤解得x=0,y=3.
答案:0,3
6若log2(x2-3x-2)+ilog2(x2+2x+1)>1,则实数x的值为 .
解析:∵log2(x2-3x-2)+ilog2(x2+2x+1)>1,
∴{■(log_2 "(" x^2 "-" 3x"-" 2")" >1"," @log_2 "(" x^2+2x+1")" =0"." )┤∴x=-2.