Bonjour,
a) n₁ x sin(i₁) = n₂ x sin(i₂)
n₁ = 1,33, n₂ = 1,00 et i₂ = 90°
⇒ sin(i₁) = sin(i₂) x n₂/n₁ = sin(90°) x 1,00/1,33 = 1/1,33
⇒ i₁ = arcsin(1/1,33) ≈ 48,75°
b) n₁ x sin(i₁) = n₂ x sin(i₂)
n₁ = 1,00, n₂ = 1,33 et i₁ = 90°
⇒ sin(i2) = sin(i₁) x n₁/n₂ = sin(90°) x 1,00/1,33 = 1/1,33
⇒ i₂ = arcsin(1/1,33) ≈ 48,75°
