I don't have any formal education in Trigonometry or Calculus, but I'm studying a book on Pre-calc before school begins this fall. I've completed College level Algebra too, so math isn't something which I have a whole lot of trouble with.
I'm actually working on a game in Unity3d, and I picked up the pre-calc book because I need to understand more about rotations, and vectors, and such, additionally I'm taking Pre-calc at a University this fall. I don't think I've run across an answer to this question yet in the book, if I didn't miss it or it hasn't yet been introduced.
For some problems in this game essentially I need to find the angle between a point an some origin in space. The question is: does the trig function I need to use depend on which quadrant the point is in?
I ponder the answer to this because it matters what angle you are computing when you decide on inputs for the trig functions.
 is this much clearer, or no?