Y = 39 * cos (2 * arctg 1 + arccos 5/13) = 39 * cos(π/2 + arccos 5/13) =
-39 * sin (arccos 5/13) = -39 * 12/13 = -36
Y = 39 * cos (2 * arctg 1 + arccos 5/13) = 39 * cos(π/2 + arccos 5/13) =
-39 * sin (arccos 5/13) = -39 * 12/13 = -36