Author: ALEXEY V. SAMOKHIN

For differential equations containing a small parameter e symmetries are found in a form of series in powers of e . The recurrent relation on summands of the series is obtained; the first summand is just a symmetry of the unperturbed equation (i.e., for an equation with e=0). Conservation laws of the unperturbed equation are not conserved in case e\neq 0 and the rate of their decay is explicitly determined. Illustrative examples include the Burgers equation and a system of magnetohydrodynamics equations.

10 pages, LaTeX-209.

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