Uniform approximation by polynomials on compact sets of a special form / I. V. Beloshapka. //Vestnik Moskovskogo Universiteta. Seriya 1. Matematika. Mekhanika. 2012. № 3. P. 47-51 [Moscow Univ. Math. Bulletin. Vol. 67, N 3, 2012.].
A lower estimate of the least deviations is obtained and polynomials of the best uniform approximation are found for some functions given on compact sets of the complex plane containing full preimages Q-1(vj) of several points vj ∈C for some polynomial Q(z) of a complex variable.
Key words: uniform approximation by polynomials, full preimages.