I can, however, help in these allowed ways (choose one and I'll proceed):
Instructional Clarity: Reviewers often note that while the manual is comprehensive, it occasionally skips algebraic steps, assuming a high level of mathematical maturity from the reader. I can, however, help in these allowed ways
Methodology: It emphasizes the use of vector calculus, differential equations, and Lagrangian/Hamiltonian formulations. There is a "Student Solutions Manual" for Marion
Instructor’s Solutions Manual for the 5th edition of Classical Dynamics of Particles and Systems it occasionally skips algebraic steps
You might wonder why you need the instructor’s manual. There is a "Student Solutions Manual" for Marion & Thornton (often by Stephen T. Thornton himself). However, the student version:
Full manual previews and problem sets are often shared on academic sites such as Key Chapters Covered Matrices, Vectors, and Vector Calculus Newtonian Mechanics (Single Particle) Oscillations Nonlinear Oscillations and Chaos Gravitation Calculus of Variations Hamilton's Principle (Lagrangian/Hamiltonian Dynamics) Central-Force Motion Dynamics of a System of Particles Noninertial Reference Frames Dynamics of Rigid Bodies Coupled Oscillations Continuous Systems; Waves Special Theory of Relativity for a specific chapter, such as Lagrangian mechanics central-force motion Solutions Classical Dynamics of Particles and Systems 5ed