1. The problem statement, all variables and given/known data A ray of light passes from air into benzene. For its deviation angle δ = |θ1 - θ2| to be 9.5°, what must be its angle of incidence? The refractive index of benzene is 1.501. 2. Relevant equations Snell's law 3. The attempt at a solution From Snell's law we have sin θ1 = 1.501 sin θ2. Here θ1 is the angle of incidence. We can rewrite θ2 = θ1 - 9.5 and substitute that into the equation to get sin θ1 = 1.501 sin (θ1 - 9.5) But how is it possible to solve for θ1 from this equation?