WKB theory?? Pls help 1. The problem statement, all variables and given/known data WKB theory and WKB approximation. Are they same?? 2. Relevant equations I have to do a presentation about WKB theory in Physics (Quantum mechanics) but I dont know how to start from the WKB theory and come to WKB approximation. i.e. I don't find a direct connection. I know WKB theory is a method of solving differential equation but I do not know how to use it to solve any differential (well..2nd order) equation. It means I do not understand what WKB theory is (the basics) :( :( 3. The attempt at a solution I tried to google and find the answer but did find a good explanation. I greatly appreciate if you can help me to understand this issue as this is vital to pass this course. Thanks.