Quasi-classical approximation method in quantum mechanics

In this study clarified the terms of classical mechanics and quantum mechanics and investigated between of them relation. Equation of Schrödinger and its a few special cases investigated which is foundation in quantum mechanics. Quassi-classical approximation method is explained which argument of the functions of such large values of solutions of finding approximate-asymtotic expressions. İn quassi-classical approximation method is found approximate expression of the functions which is one of the mathematical problems that solution of the equation. But in many cases this is impossible that findig accurately the functions. For this purpose, from the approximation methods are utilazed. Here too various orthogonal polynomials, this type of polynomials is primitive subject that Fourier series expansions. And this study some important properties of orthogonal polynomials are also included. Finding asymtotic expressions are main problem of method which evaluated that to occur inaccurary in approximation methods. Here the theory of the best approach of functions are known that the theory is very important and unique contribution to them. Our commitment to this issue in this study are associated with it.