On existence of a best uniform approximation of a function in two variables by the sums \(\varphi (x)+ \psi (y)\)
This paper is concerned with the existence of a best uniform approximation to a real function in two variables by the sums of functions in one variable. The authors present geometric conditions imposed on the domain of definition of functions which guarantee existence for a best approximation. Obtained results are demonstrated by some examples.
scientific article; zbMATH DE number 923538
scientific article