The complex number $\large\frac{1+2i}{1-i}$ lies in which quadrant?

Question

(A) I quadrant

(B) II quadrant

(C) III quadrant

(D) IV quadrant

Answer 1

$\large\frac{1+2i}{1-i}=\frac{1+2i}{1-i}\times\frac{1+i}{1+i}$

$=\large\frac{1-2+3i}{2}=\frac{-1+3i}{2}$

which lies in 2nd quadrant.