把Bernstein-Kantorovich算子修正为保持线性函数不变的算子Ln(f,x).并研究了Ln(f,x)的逼近性质,得到了逼近正定理,扩充了以前的结果.
Bernstein-Kantorovich operators are modified to operators which preserve linear functions.Furthermore approximate properties of Ln(f,x) are studied and a direct approximate theorem is obtained.This result expands the previous one.