derive the angle of limitation sinθ=[(n2^2-n3^2)^1/2]/n1
n1 is the air out side of the fibre
n2 is inside of the fibre
n3 is the fibre wall
2. Relevant equations
3. The attempt at a solution
I’m pretty stuck and don’t really know where to go after getting the angles from geometry. I have pi/2-θ2 for the angle of reflection off of the optical wall. So I put this angle into Snells Law then just kind of get stuck.