• # question_answer The complex number $\frac{1+2i}{1-i}$ lies in which quadrant of the complex plane [MP PET 2001] A) First B) Second C) Third D) Fourth

$z=\frac{1+2i}{1-i}$$\Rightarrow \,z=\frac{1+2i}{1-i}\times \frac{1+i}{1+i}$$=\frac{-1}{2}+i\frac{3}{2}$ This complex number will lie in the II quadrant. Ans.