对逐段凸函数逼近的Jackson型估计

Jackson type estimates for the degree of approximation for piecewise conves furctions

对不满足文献［１］中定理条件的部分可微函数，在逐段严格凸的条件下，利用插值多项式讨论了其共凸逼近，给出了逼近阶的Ｊａｃｋｓｏｎ型估计，同时还得到了它一、二阶导函数的逼近阶估计式。

For some differentiable functions, if they are out of the condition of theorem of , the proplem of coconvex approximation are discussed using interpolation polynomials. Jackson type estimates for degree of coconvex approximation are obtained, and estimates of its first and second derivatives are given.