A notebook on nonlinear oscillators for physics students: weakly nonlinear perturbation, Duffing, van der Pol, and driven resonances, with phase portraits explained in words and equations.

For advanced classical mechanics or nonlinear dynamics electives.

• Multiple-scale and Lindstedt methods
• Duffing hardening and softening
• van der Pol limit cycles
• Driven response and jump phenomena
• Worked numerical-check problems