w=z(z+i)=(a-i)/(1-i)*[(a-i)/(1-i)+i]
=(a-i)/(1-i)*(a+1)/(1-i)
=(a+1)(a-i)/(-2i)
=(a+1)(ai+1)/2
故其虚部减去它的实部所得的差为
(a+1)a/2-(a+1)/2=3/2
(a+1)a-(a+1)=3
(a+1)(a-1)=3
a^2=4
a=2(a=-2
w=z(z+i)=(a-i)/(1-i)*[(a-i)/(1-i)+i]
=(a-i)/(1-i)*(a+1)/(1-i)
=(a+1)(a-i)/(-2i)
=(a+1)(ai+1)/2
故其虚部减去它的实部所得的差为
(a+1)a/2-(a+1)/2=3/2
(a+1)a-(a+1)=3
(a+1)(a-1)=3
a^2=4
a=2(a=-2