Consider a light ray travelling in air is incident into a medium of refractive index \( \sqrt{2n} \). The incident angle is twice that of refracting angle. Then, the angle of incidence will be:
\( \sin^{-1}(\sqrt{n}) \)
\( \cos^{-1}\!\left(\sqrt{\frac{n}{2}}\right) \)
\( \sin^{-1}(\sqrt{2n}) \)
\( 2 \cos^{-1}\!\left(\sqrt{\frac{n}{2}}\right) \)