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Keywords:
King type operator; $q$-Bernstein-Schurer operator; Korovich type approximation theorem; rate of convergence; Voronovskaja-type result; modulus of continuity
Summary:
Very recently the $q$-Bernstein-Schurer operators which reproduce only constant function were introduced and studied by C. V. Muraru (2011). Inspired by J. P. King, Positive linear operators which preserve $x^{2}$ (2003), in this paper we modify $q$-Bernstein-Schurer operators to King type modification of $q$-Bernstein-Schurer operators, so that these operators reproduce constant as well as quadratic test functions $x^{2}$ and study the approximation properties of these operators. We establish a convergence theorem of Korovkin type. We also get some estimations for the rate of convergence of these operators by using modulus of continuity. Furthermore, we give a Voronovskaja-type asymptotic formula for these operators.
References:
[1] Agratini, O., Nowak, G.: On a generalization of Bleimann, Butzer and Hahn operators based on $q$-integers. Math. Comput. Modelling 53 (2011), 699-706. DOI 10.1016/j.mcm.2010.10.006 | MR 2769444 | Zbl 1217.33033
[2] Aral, A.: A generalization of Szász-Mirakyan operators based on $q$-integers. Math. Comput. Modelling 47 (2008), 1052-1062. DOI 10.1016/j.mcm.2007.06.018 | MR 2413735 | Zbl 1144.41303
[3] Chen, W. Z.: Operators Approximation Theory. Xiamen University Press Xiamen (1989), Chinese.
[4] DeVore, R. A., Lorentz, G. G.: Constructive Approximation. Grundlehren der Mathematischen Wissenschaften 303. Springer Berlin (1993). DOI 10.1007/978-3-662-02888-9 | MR 1261635
[5] Doğru, O., Örkcü, M.: Statistical approximation by a modification of $q$-Meyer-König Zeller operators. Appl. Math. Lett. 23 (2010), 261-266. DOI 10.1016/j.aml.2009.09.018 | MR 2565187
[6] Gal, S. G.: Voronovskaja's theorem, shape preserving properties and iterations for complex $q$-Bernstein polynomials. Stud. Sci. Math. Hung. 48 (2011), 23-43. MR 2868175
[7] Gasper, G., Rahman, M.: Basic Hypergeometric Series. Encyclopedia of Mathematics and Its Applications 34. Cambridge University Press Cambridge (1990). MR 1052153
[8] Gupta, V., Radu, C.: Statistical approximation properties of $q$-Baskakov-Kantorovich operators. Cent. Eur. J. Math. 7 (2009), 809-818. DOI 10.2478/s11533-009-0055-y | MR 2563452 | Zbl 1183.41015
[9] Kac, V., Cheung, P.: Quantum Calculus. Universitext. Springer New York (2002). MR 1865777
[10] King, J. P.: Positive linear operators which preserve $x^{2}$. Acta Math. Hung. 99 (2003), 203-208. DOI 10.1023/A:1024571126455 | MR 1973095 | Zbl 1027.41028
[11] Mahmudov, N. I.: Approximation properties of complex $q$-Szász-Mirakjan operators in compact disks. Comput. Math. Appl. 60 (2010), 1784-1791. DOI 10.1016/j.camwa.2010.07.009 | MR 2679142 | Zbl 1202.30061
[12] Mahmudov, N. I.: Approximation by genuine $q$-Bernstein-Durrmeyer polynomials in compact disks. Hacet. J. Math. Stat. 40 (2011), 77-89. MR 2663881 | Zbl 1230.30020
[13] Muraru, C.-V.: Note on $q$-Bernstein-Schurer operators. Stud. Univ. Babeş-Bolyai Math. 56 (2011), 489-495. MR 2843706
[14] Ostrovska, S.: $q$-Bernstein polynomials of the Cauchy kernel. Appl. Math. Comput. 198 (2008), 261-270. DOI 10.1016/j.amc.2007.08.066 | MR 2403947 | Zbl 1149.41002
[15] Phillips, G. M.: Bernstein polynomials based on the $q$-integers. Ann. Numer. Math. 4 (1997), 511-518. MR 1422700 | Zbl 0881.41008
[16] Videnskii, V. S.: On $q$-Bernstein polynomials and related positive linear operators. Problems of Modern Mathematics and Mathematical Education Hertzen readings St.-Petersburg (2004), 118-126 Russian.
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