1. The problem statement, all variables and given/known data The problem I am having troubles with is proving the deflection of a ray by a prism can be represented by a specific equation : θd = θ - α + arcsin(sin(α)√(n2 - sin2(α)) - sin(α)cos(α)). I have derived another form of the deflection equation for a prism and I am attempting to move it into the form requested but I am getting stuck on some trigonometry. 2. Relevant equations α is the apex angle of the prism and θ is the angle of incidence on the prism. 3. The attempt at a solution See attachments.