Question

已知复数z1=2-i与z2=x(1-i)+y(1+i)是共轭复数,z=x+yi,求|z|

Answer 1

z2=x(1-i)+y(1+i)=(x+y)-(x-y)i

x+y=2 x-y=-1

x=0.5 y=1.5

|z|=根号(0.25+2.25)=根号10除以2