PageHeader : Funkcialaj Ekvacioj' 16 (1973)' 53-67 Title : Limit Cycles of a Certain Nonlinear Differential Title : Equation of the Second Order AuthorInfo : By Y?kiti SAT? AuthorInfo : (Saitama University) section : 1. Introduction. section : 2. Existence of limit cycles in the case where $\delta=-1$ . Throughout this section we $\sup_{\backslash }$ pose that $\delta=-1$ and (2. 1) $g(x)$ is differentiable at $x=0$ ' $x=\alpha_{i}(i=1,2)$ and $g^{\prime}(\alpha_{i})>0(i=1,2)$ . As usual' equation (1. 1) can be transformed into the system section : 3. Existence of limit cycles in the case where $\delta=1$ . section : References