已知复数z=a-i/1-i(a大于0),且复数w=z(z+i)的虚部减去它的实部所得的差为3/2,求复数w

问题描述:

已知复数z=a-i/1-i(a大于0),且复数w=z(z+i)的虚部减去它的实部所得的差为3/2,求复数w

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)=3a^2=4a=2(a=-2