Find ∣z∣|z|∣z∣ if z=frac1+2i1−iz = \\frac{1+2i}{1-i}z=frac1+2i1−i.
sqrt5/2\\sqrt{5}/2sqrt5/2
sqrt2.5\\sqrt{2.5}sqrt2.5
2.52.52.5
sqrt5\\sqrt{5}sqrt5