Answer:
η = 2.2
Explanation:
The index of refraction is given by the following formula:
[tex]\eta = \frac{Sin\ \theta_i}{Sin\ \theta r}[/tex]
where,
η = index of refraction of cubic zirconia = ?
[tex]\theta_i[/tex] = angle of incidence = 56°
[tex]\theta_r[/tex] = angle of refraction = 22°
Therefore,
[tex]\eta = \frac{Sin\ 56^o}{Sin\ 22^o}\\\\\eta = \frac{0.829}{0.375}[/tex]
η = 2.2