What is the critical angle for light passing from mineral oil (n=1.47) to air (n=1.00)?

Question

What is the critical angle for light passing from mineral oil (n=1.47) to air (n=1.00)?

Please show work

Thank you

Answer 1

Let θ₀ is critical angle, then sinθ₀/sin90° = 1.00/1.47; θ₀ = sin^-1(1.00/1.47) = 42.9°.