Abstract. De la Vallée Poussin means are used to prove Jackson--Favard type estimates for weighted algebraic polynomials with Jacobi and Laguerre-like weights.

AMS Subject Classification (1991): 41A10, 42C10, 33C45

Keyword(s): De la Vallée Poussin mean, Jackson-type inequality, weighted polynomial approximation, Laguerre and Jacobi polynomials

Received March 29, 2007, and in revised form April 28, 2008. (Registered under 6009/2009.)