|Z|=根2
|Z^2|=2
令Z^2=a+2i则
a^2+2^2=2^2
a=0 (后面最好画图)
Z^2=2i
Z=1+i
Z(1,1) Z^2(0,2) Z-Z^2(1,-1)
面积=底乘高除2=2*1/2=1