3.2复数的四则运算测试题一、选择题(每小题5分,共20分)1.复数3(1i)的虚部为()A.3B.—3C.2D.—2答案:D2.i是虚数单位i1i,()A.11i22B.11i22C.11i22D.11i22答案:A3.已知zC,满足不等式i0zzz≤的点Z的集合用阴影表示为()答案:C4.设复数z满足1i1zz,则1z()A.0B.1C.2D.2答案:C二、填空题(每小题5分,共10分)5.312i3i的值是.答案:17i106.已知复数032iz,复数z满足003zzzz,则复数.答案:31i2三、解答题(每小题10分,共20分)7.已知复数1z满足1(1i)15iz,22iza,其中i为虚数单位,aR,若121zzz,求a的取值范围.用心爱心专心1解:由题意,得115i23i1iz,于是21242i(4)4zzaa,113z,则有2(4)413a,即2870aa,解得17a.8.已知复数1z、2z满足2212121052zzzz,且122zz为纯虚数,求证:123zz为实数.证明:由题意可设122izzk(k为实数,且0k),则12i2zkz,代入2212121052zzzz,得22222210(i2)52(i2)kzzkzz,化简,得222224942i10i0zkzk,解得221i749kkz,1i27kkz,123zzk,或221i749kkz,1i27kkz,123zzk.即证123zz为实数.用心爱心专心2