Q72 / 180 · COMEDK 2014 · Mathematics
If a complex number lies in the III quadrant. Find the quadrant in which its conjugate lies.
- AI quadrant
- Correct answerBII quadrant
- CIII quadrant
- DIV quadrant
Solution
Let $z=a+i b$
Then, in third quadrant $a < 0, b < 0$.
Its conjugate $\bar{z}=\overline{a+i b}=a-i b=a+(-i b)$
$=a+i k$, where $k=-b$
$\Rightarrow \quad a < 0, k>0$
$\Rightarrow \quad \bar{z}$ lies in II quadrant.
Hence, the correct answer is option: 'B'.