Question

The argument of the complex number -1 + i $\sqrt{3}$ is
[MP PET 1994]

• A. $-{60}^o$
• B. ${60}^o$
• C. ${120}^o$
• D. $-{120}^o$

Answer 1

The correct option is C ${120}^o$

$arg(-1+i\sqrt{3})=ta{n}^{-1}\left(\frac{\sqrt{3}}{-1}\right)={120}^o$ because it lies in second quadrant.