3 7 6 D O C U M E N T 2 2 2 C A L C U L A T I O N S AD. [19 216.1]. Written on the back of Doc. 219. [1]Dated by the fact that the calculations are written on the back of the preceding document. cosψ 2ϕ 1+ cosαcot 1 2ϕ)( cot + ( 1 2αcot 2ϕ) cos + ---------------------------------------------------------------------------- = 1 2ϕ cot + --------------------------------------ϕ2cotα2cos+1 = cotψ 2ϕ 2αcos 2ϕ cos + sin = 1 1 2α)cos cos – ( 2ϕ –= 1 2αcos 2ϕ sin –= sinϕ cosϕ sinα = 1 45°