Handout 15: Describing functions. Introduction Eric feron March 3 1. 2004 General Philosophy General reponse of arbitrary nonlinear systems is somewhat complicated We usually know the systems we work with Work with finite families of 'most likely responsesHandout 15: Describing functions, Introduction Eric Feron March 31, 2004 General Philosophy General reponse of arbitrary nonlinear systems is somewhat complicated. We usually know the systems we work with. Work with finite families of ’most likely responses’. 1