[tex]i=60^o \\ r=45^o \\ n_1=1 \\ n_2-? \\ \bold{Legea \ II \ a \ refractiei:} \ \boxed{\frac{\sin i}{\sin r}=\frac{n_2}{n_1}} \\ \Rightarrow n_2=\frac{\sin i \cdot n_1}{\sin r}=\frac{\sin 60^o \cdot 1}{\sin 45^o } \\ \Rightarrow n_2= \frac{\sqrt3}{2} \cdot \frac{2}{\sqrt{2}}=\frac{\sqrt3}{\sqrt2}=\frac{\sqrt6}{2} \\ \Rightarrow \boxed{n_2 \approx 1,22}[/tex]