Don't mind the Alvira bit. Please explain algebraically how the diagram is in this equation: d km= 3tan((pi)x)
note that on a right triangle, we have where is the opposite side and is the adjacent side.
thus, from your figure, we have ..
now, how come that ?
it was said that light spans a complete rotation (1 rev = ) every two minutes and thus the rate of revolution is per minute.
so, at time t minutes, the light spans times that time , and that is the angle of rotation, thus we have
aww, you were using .. well it is just the same.. they are just dummy variables.