Mathematics · important
Quadrant-wise arguments for JEE
Modulus and argument (or amplitude) of a complex number
Formula
\[\arg(a+ib)=\begin{cases}\tan^{-1}(b/a),&a>0\\ \pi+\tan^{-1}(b/a),&a<0,\ b\ge 0\\ -\pi+\tan^{-1}(b/a),&a<0,\ b<0\\ \pi/2,&a=0,\ b>0\\ -\pi/2,&a=0,\ b<0\end{cases}\]
Variables: \(a,b\in\mathbb R\)
Conditions: \(a,b\) not both zero
Correct determination of argument in JEE problems.