First Integrals, Integrating Factors, and Invariant Solutions of the Path Equation Based on Noether and λ -Symmetries

Abstract

We analyze Noether and $\lambda$-symmetries of the path equation describing the minimum drag work. First, the partial Lagrangian for the governing equation is constructed, and then the determining equations are obtained based on the partial Lagrangian approach. For specific altitude functions, Noether symmetry classification is carried out and the first integrals, conservation laws and group invariant solutions are obtained and classified. Then, secondly, by using the mathematical relationship with Lie point symmetries we investigate $\lambda$-symmetry properties and the corresponding reduction forms, integrating factors, and first integrals for specific altitude functions of the governing equation. Furthermore, we apply the Jacobi last multiplier method as a different approach to determine the new forms of $\lambda$-symmetries. Finally, we compare the results obtained from different classifications.