Two vectors \( \vec{A} \) and \( \vec{B} \) have equal magnitudes. If magnitude of \( \vec{A} + \vec{B} \) is equal to two times the magnitude of \( \vec{A} - \vec{B} \), then the angle between \( \vec{A} \) and \( \vec{B} \) will be:
\( \sin^{-1}\!\left(\frac{3}{5}\right) \)
\( \sin^{-1}\!\left(\frac{1}{3}\right) \)
\( \cos^{-1}\!\left(\frac{3}{5}\right) \)
\( \cos^{-1}\!\left(\frac{1}{3}\right) \)
