Question

A light beam is incident on a piece of fluorite (n = 1.434) at the Brewster's angle.

Answer 1

The Brewster angle is the angle can be found through this equation
θ=arctan(n2/n1).
This came from Snell's Law:
n1sinθ=n2sin(90-θ)
          =n2cosθ
n2/n1=tanθ --- θ=arctan(n2/n1)=arctan(1.434)=55.11 degrees

Next, the angle of refraction can be found by using Snell's Law
n1sinθ=n2sinθ'
sin(55.11)=1.434sinθ'
sinθ'=sin(55.11)/1.434=0.572 --- θ'=arcsin(0.572)=34.89 degrees