【摘要】 本文考察了下列周期边值问题:u′=f(t,u),u(o)=u(2π) (1)当下解不大于或不小于上解时,利用单调迭代方法给出了问题(1)的最大解、最小解新的存在定理,与文的结果互不包含。更多还原

【Abstract】 Using monotone iterative technique we obtain the existence theorem of the minimal and maximal solutions of the periodic boundary value problem: u’=f(t, u), u(O) =u(2π), when the lower solution less than or greater than the upper solution. The results discussed in this paper are different from V. Lakshmikantham’s, that is, one can not include the other.更多还原