If z+x+iy then (z)=√x2+y2 z1=2−i,z2=1+i, find ∣∣z1+z2+1z1−z2+i∣∣.
Ifz+x+iy then (z)=√x2+y2We have,z1=2−i,z2=1+iz1+z2=2−i+1+i=3And z1−z2=2−i−1−i=1−2iz1+z2+1z1−z2+i=3+11−2i+i=41−i=41−i×1+i1+i=4(1+i)12+12=4(1+i)2=2(1+i)∴ ∣∣z1+z2+1z1−z2+i∣∣=|2(1+i)|=|2||1+i| (∵ |z1z2|=|z1|×|z2|)=2×√12+12=2×√2=2√2