Stud. Univ. Babe¸ s-Bolyai Math. 56(2011), No. 2, 315–325 Approximation by max-product Lagrange interpolation operators Lucian Coroianu and Sorin G. Gal Abstract. The aim of this note is to associate to the Lagrange interpola- tory polynomials on various systems of nodes (including the equidistant and the Jacobi nodes), continuous piecewise rational interpolatory op- erators of the so-called max-product kind, uniformly convergent to the function f , with Jackson-type rates of approximation. Mathematics Subject Classification (2010): 41A05, 41A25, 41A35. Keywords: Nonlinear Lagrange interpolation operators of max-product kind, equidistant nodes, Jacobi nodes, degree of approximation. 1. Introduction Based on the Open Problem 5.5.4, pp. 324-326 in [12], in a series of recent papers we have introduced and studied the so-called max-product operators attached to the Bernstein polynomials and to other linear Bernstein-type op- erators, like those of Favard-Sz´ asz-Mirakjan operators (truncated and non- truncated case), see [3], Baskakov operators (truncated and nontruncated case), Meyer-K¨onig and Zeller operators, see [4] and Bleimann-Butzer-Hahn operators, see [5]. For example, in the two recent papers [1], [2], starting from the linear Bernstein operators B n (f )(x)= n  k=0 b n,k (x)f (k/n), where b n,k (x)= ( n k ) x k (1 − x) n-k , written in the equivalent form B n (f )(x)= ∑ n k=0 b n,k (x)f (k/n) ∑ n k=0 b n,k (x)