问题
选择题
若(x2-1)+(x2+3x+2)i是纯虚数,则实数x的值是( )
A.1
B.-1
C.1或-1
D.-1或-2
答案
(x2-1)+(x2+3x+2)i是纯虚数,则x2-1=0 x2+3x+2≠0
解得:x=1
故选A
若(x2-1)+(x2+3x+2)i是纯虚数,则实数x的值是( )
A.1
B.-1
C.1或-1
D.-1或-2
(x2-1)+(x2+3x+2)i是纯虚数,则x2-1=0 x2+3x+2≠0
解得:x=1
故选A