On the Number of Stable Periods of a Differential Equation of the van der Pol Type

Van der Pol's differential equation with forcing term can, for some values of the parameter
b
, have stable periodic solutions of two distinct periods. The paper examines whether, with a generalization of the equation not too unlike the original, there can be more than two distinct periods. The answer is affirmative. The example (with three periods-in principle, there can be many), while within the permissible limits, is very sophisticated for its kind. But if the phenomenon can happen at all, it may be presumed to happen in much simpler cases.