The angle between vector \( \vec{Q} \) and the resultant of \( (2\vec{Q} + 2\vec{P}) \) and \( (2\vec{Q} - 2\vec{P}) \) is:
$\tan^{-1}\left(2Q/P\right)$
$0^\circ$
$\tan^{-1}\frac{(2\vec{Q} - 2\vec{P})}{2\vec{Q} + 2\vec{P}}$
$\tan^{-1}\left(P/Q\right)$