Question

设复数z= 2+i (1+i) 2 （i为虚数单位），则复数z的虚部是______．

Answer 1

z=

2+i

(1+i) 2 =

2+i

2i =

(2+i)i

2i•i =

2i-1

-2 =

1

2 -i

故其虚部为：-1

故答案为：-1