title: Where can I learn the basics of game physics and the math behind it?
body: <p>I taken math in college (trigonometry, calculus II...) but I don't know why you use tan, arctan, etc., in game physics.  I know I can find working code and understand everything except why I am using a particular trig function, but I don't want that.</p>
  
  <p>I want to know why I am using arctan or sin.  Where can I learn about why I am using that particular math function to make a ball bounce realistically?</p>
  
  <p>Thanks for any help.</p>
  
  <p>EDIT:  Do I need to have taken an entry level physics class to understand game physics?</p>