摘要
近年来，非主型方程的离散现象引起了人们的重视。
In this paper, the Goursat problem for a class of nonprincipal form's equation:Where a = const, b is real number, K is odd integer, is considered. Using characteristic transformation, the problem (G) is changed into the singular Picard problem for the EPD equationWe have proved that discrete phenomena in existence and uniqueness in the problem (G) is appeared if and only ifBesides, we have given the integral expression of solution for the problem (G), when b<ka.
