On the iterative solution of finite element systems of equations
In the paper, we give an existence theorem of periodic solution for Liénard equation , . As a result, we estimate the amplitude (maximal -value) of the limit cycle of the van der Pol equation , from above by for every . The result is an improvement of the author’s previous estimation .
Our aim in this paper is to obtain sufficient conditions under which for every there exists a solution of the functional differential equation such that .