Key Equations

Speed of light	$c=2.99792458\times {10}^8\text{m/s}\approx 3.00\times {10}^8\text{m/s}$
Index of refraction	$n=\frac{c}{v}$
Law of reflection	${\theta }_{\text{r}}={\theta }_{\text{i}}$
Law of refraction (Snell’s law)	$n_1\text{sin}{\theta }_1=n_2\text{sin}{\theta }_2$
Critical angle	${\theta }_{\text{c}}={\text{sin}}^{\mathrm{-1}}\left(\frac{n_2}{n_1}\right)\text{for}{n}_1>n_2$
Malus’s law	$I=I_0{\text{cos}}^2\theta$
Brewster’s law	$\text{tan}{\theta }_{\text{b}}=\frac{n_2}{n_1}$