Аннотации:
In the present paper we establish the necessary and sufficient conditions for two ordinary differential equations of the form y″2 + A(x, y, y′)y″ + B(x, y, y′) = 0 to be equivalent under the action of the pseudogroup of contact transformations. These conditions are formulated in terms of integrals of some one-dimensional distributions. © 2013 Pleiades Publishing, Ltd.