Key Equations

Speed of light	$c = 2.99792458 \times 10^{8} m/s \approx 3.00 \times 10^{8} m/s$
Index of refraction	$n = \frac{c}{v}$
Law of reflection	$θ_{r} = θ_{i}$
Law of refraction (Snell’s law)	$n_{1} sin θ_{1} = n_{2} sin θ_{2}$
Critical angle	$θ_{c} = {sin}^{−1} (\frac{n_{2}}{n_{1}}) for n_{1} > n_{2}$
Malus’s law	$I = I_{0} {cos}^{2} θ$
Brewster’s law	$tan θ_{b} = \frac{n_{2}}{n_{1}}$