As we know,
\(\mu=\frac{\sin \theta_{\mathrm{iB}}}{\sin \left(\frac{\pi}{2}-\theta_{\mathrm{iB}}\right)}\)
where, \(\theta_{\mathrm{iB}}\) is Brewster's angle of incidence,
And, \(\mu=\frac{1}{\sin \theta_{\text {ic }}}\)
Onsolving we get, relative refractive index of the two media.