内容正文:
专题七 数系的扩充与复数的引入
[考点1] 复数的概念
1.(2023全国甲卷(理),2)若复数(a+i)(1
-ai)=2,a∈R,则a= ( )
A.-1 B.-2
C.1 D.2
2.(2023全国乙卷(文),1)|2+i2+2i3|=
( )
A.1 B.2
C.5 D.5
3.(2022全国乙卷(理),2)已知z=1-2i,且
z+az+b=0,其中a,b为实数,则( )
A.a=1,b=-2 B.a=-1,b=2
C.a=1,b=2 D.a=-1,b=-2
4.(2022全国乙卷(文),2)设(1+2i)a+b=
2i,其中a,b为实数,则 ( )
A.a=1,b=-1 B.a=1,b=1
C.a=-1,b=1 D.a=-1,b=-1
5.(2022浙江卷,2)已知a,b∈R,a+3i=(b
+i)i(i为虚数单位),则 ( )
A.a=1,b=-3 B.a=-1,b=3
C.a=-1,b=-3 D.a=1,b=3
6.(2020全国Ⅲ卷(理),2)复数 11-3i
的虚
部是 ( )
A.-310 B.-
1
10
C.110 D.
3
10
7.(2020浙江卷,2)已知a∈R,若a-1+(a
-2)i(i为虚数单位)是实数,则a= ( )
A.1 B.-1
C.2 D.-2
8.(2019全国Ⅱ卷(文),2)设z=i(2+i),则
z= ( )
A.1+2i B.-1+2i
C.1-2i D.-1-2i
9.(2023上海卷,6)已知复数z=1+i(i为虚
数单位),则|1-iz|= .
10.(2020江苏卷,2)已知i是虚数单位,则
复数z=(1+i)(2-i)的实部是 .
11.(2019江苏卷,2)已知复数(a+2i)(1+i)
的实部为0,其中i为虚数单位,则实数a
的值是 .
[考点2] 复数的四则运算
1.(2023新课标Ⅰ卷,2)已知z=1-i2+2i
,则z
-z= ( )
A.-i B.i
C.0 D.1
2.(2023全国甲卷(文),2) 5
(1+i3)
(2+i)(2-i)=
( )
A.-1 B.1
C.1-i D.1+i
3.(2023全国乙卷(理),1)设z= 2+i
1+i2+i5
,
则z= ( )
A.1-2i B.1+2i
C.2-i D.2+i
4.(2022全国甲卷(理),1)若z=-1+ 3i,
则 z zz-1
= ( )
A.-1+ 3i B.-1- 3i
C.-13+
3
3i D.-
1
3-
3
3i
5.(2022新高考Ⅰ卷,2)若i(1-z)=1,则z
+z= ( )
A.-2 B.-1
C.1 D.2
6.(2022新高考Ⅱ卷,2)(2+2i)(1-2i)=
( )
A.-2+4i B.-2-4i
C.6+2i D.6-2i
7.(2021全国乙卷(理),1)设2(z+z)+3(z
-z)=4+6i,则z= ( )
A.1-2i B.1+2i
C.1+i D.1-i
8.(2021全国乙卷(文),2)设iz=4+3i,则z
= ( )
A.-3-4i B.-3+4i
C.3-4i D.3+4i
94
专题七 数系的扩充与复数的引入
9.(2021全国甲卷(理),3)已知(1-i)2z=
3+2i,则z= ( )
A.-1-32i B.-1+
3
2i
C.-32+i D.-
3
2-i
10.(2021新高考Ⅰ卷,2)已知z=2-i,则
z(z+i)= ( )
A.6-2i B.4-2i
C.6+2i D.4+2i
11.(2021北京卷,2)在复平面内,复数z满
足(1-i)z=2,则z= ( )
A.2+i B.-2-i
C.1-i D.1+i
12.(2021浙江卷,2)已知a∈R,(1+ai)i=
3+i(i为虚数单位),则a= ( )
A.-1 B.1
C.-3 D.3
13.(2020全国Ⅰ卷(理),