Question

i是虚数单位，计算

1-i

1+i

+

1+i

1-i

=______．

Answer 1

1-i

1+i

+

1+i

1-i

=

(1-i)2

(1+i)(1-i)

+

(1+i)2

(1+i)(1-i)

=

-2i

2

+

2i

2

=0，
故答案为 0．