摘要
This paper cosiders the existence of nontrivial periodic solutions of the differentialdifference equationsx′(t)=-f(x(t-1)),x′(t)=-(f(x(t-1)+f(x(t-2))),and(x′(t)=f(x(t),y(t),x(t-1),y(t-1)),y′(t)=g(x(t),y(t),x(t-1),y(t-1)).)Some new existence criteria are obtained.
This paper cosiders the existence of nontrivial periodic solutions of the differential difference equations x'(t) = - f(x(t-1)), x'(t) = - (f(x(t-1) + f(x(t-2))), and [GRAPHICS] Some new existence criteria are obtained.
基金
Sapported by the National Science Foundation of China.
