1. The problem statement, all variables and given/known data I had a homework problem which was already due. I got the solutions for the homework and still don't understand where the solution is coming from. The question and solution are located here: http://ircamera.as.arizona.edu/Astr_540/PS3_soln.pdf The problem is #3. 2. Relevant equations The equations are shown in the solution. 3. The attempt at a solution My attempt really wasn't much. I really didn't have much time to work on it. Now that I've looked over the solution, it looks completely foreign to me haha maybe some of you guys can explain what's happening in the solution.