a1 Department of Mathematics, Babeş-Bolyai University, Mihail Kogălniceanu nr. 1, RO 400084, Cluj-Napoca, Romania; Email: (firstname.lastname@example.org)
Direct and converse theorems are established for the q-Bernstein polynomials introduced by G. M. Phillips. The direct approximation theorems are given for the second-order Ditzian–Totik modulus of smoothness. The converse results are theorems of Berens–Lorentz type.
(Received October 12 2007)
2000 Mathematics subject classification