Classification of critical points and caustic of the function of codimension four with application

الملخص EN

In this paper we classified the critical points of function of one variable of codimension four by finding the geometric description of caustic, investigate the propagation of the critical points in the space of parameter.

For the application we gave an example to study the bifurcation solutions of nonlinear fourth order differential equation by using Lyapunov-Schmidt method.