\begin{equation} n = \frac{c}{v} \qquad \textnormal{(Index of refraction)} \end{equation} \begin{equation} \lambda = \frac{\lambda_0}{n} \qquad \textnormal{(Wavelength in medium)} \end{equation}
\begin{equation} \pi_r = \pi_a \qquad \textnormal{(Law of reflection)} \end{equation} \begin{equation} n_{\rho} \, \textnormal{ sin } \pi_{\rho} = n_{\omega} \, \textnormal{ sin } \pi_{\omega} \qquad \textnormal{(Law of refraction)} \end{equation}
\begin{equation} \textnormal{ sin } \beta_{crit} = \frac{n_{\lambda}}{n_{\delta}} \qquad \textnormal{(Critical angle)} \end{equation}
\begin{equation} I = I_{max} \textnormal{ cos}^2 \, \tau \qquad \textnormal{(Malus' law)} \end{equation}
\begin{equation} \textnormal{ tan } \gamma_p = \frac{n_{\lambda}}{n_{\delta}} \qquad \textnormal{(Brewster's law)} \end{equation}