Abstract
We extend the results of Singh and Mahajan (Int J Math Math Sci 2008:9, 2008) which in turn generalizes the result of Lal and Yadav (Bull Cal Math Soc 93:191–196, 2001). In this paper, we determine the degree of approximation of functions \( \widetilde{f\,} \in H_{\omega } , \) a new Banach space using \( \left( {T.\,E^{\,1} } \right) \) summability means of conjugate series of Fourier series. Also, some corollaries have also been deduced from our main theorem and particular cases.
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References
Alexits G (1961) Convergence problems of orthogonal series. Pergamon Elmsford, New York
Bachman G, Narici L, Beckenstien E (2000) Fourier and wavelet analysis. Springer Verlag, New York
Başar F (2011) Summability theory and its applications. Bentham Science Publishers, İstanbul
Braha NL (2010) The asymptotic representation for the best approximation of some classes nonperiodic continuous functions. Int J Pure Appl Math 64(1):1–8
Bustamante J, Roldan CC (2006) Direct and inverse results in Hölder norms. J Approx Theory 138:112–123
Chandra P (1982) On the generalized Fejér means in the metric of the Hölder space. Math, Nachr 109:39–45
Chandra P (1990) Degree of approximation of functions in the Hölder metric by Borel’s means. J Math Anal Appl 149:236–246
Chen JT, Jeng YS (1996) Dual series representation and its applications to a string subjected to support motions. Adv Eng Softw 27(3):227–238
Chen JT, Hong H-K, Yeh CS, Chyuan SW (1996) Integral representations and regularizations for a divergent series solution of a beam subjected to support motions. Earthq Engg Struct Dyn 25(9):909–925
Das G, Ghosh T, Ray BK (1995) Degree of approximation of functions in the Hölder metric by (e, c) Means. Proc Indian Acad Sci (Math Sci) 105:315–327
Das G, Ghosh T, Ray BK (1996) Degree of approximation of functions by their Fourier series in the generalized Hölder metric. Proc Indian Acad Sci (Math Sci) 106(2):139–153
Gil’ MI (2008) Estimates for entries of matrix valued functions of infinite matrices. Math Phys Anal Geom 11:175–186
Guven A (2012) Approximation by means of hexagonal Fourier series in Hölder norms. J Class Anal 1(1):43–52
Khan HH (1974a) On the degree of approximation of a functions belonging to the class Lip(α, p). Indian J Pure Appl Math 5:132–136
Khan HH (1974) Approximation of classes of functions. Ph.D. Thesis, AMU Aligarh
Lal S, Yadav KNS (2001) On degree of approximation of function belonging to the Lipschitz class by (C, 1)(E, 1) means of its Fourier series. Bull Cal Math Soc 93:191–196
Lenski W, Szal B (2015) Approximation of functions from L p(w)β by general linear operators. Acta Math Hungar. https://doi.org/10.1007/s10474-015-0541-6
Mishra VN, Mishra LN (2012) Trigonometric approximation in L p(p ≥ 1) − spaces. Int J Contemp Math Sci 7:909–918
Mishra VN, Khatri K, Mishra LN (2012) Product (N, p n)(C, 1) summability of a sequence of Fourier coefficients. Math Sci (Springer open access) 6:38
Mishra LN, Mishra VN, Khatri K (2014a) Deepmala, on the trigonometric approximation of signals belonging to generalized weighted Lipschitz W(L r, ξ(t))(r ≥ 1) − class by matrix (C 1. N p) operator of conjugate series of its Fourier series. Appl Math Comput 237:252–2631
Mishra VN, Khatri K, Mishra LN (2014b) Deepmala, Trigonometric approximation of periodic Signals belonging to generalized weighted Lipschitz W(L r, ξ(t)), (r ≥ 1) − class by Nörlund-Euler (N, p n)(E, q) operator of conjugate series of its Fourier series. J Class Anal 5(2):91–105
Mittal ML, Rhoades BE (2000) Degree of approximation of functions in a normed space. J Comp Anal Appl 2(1):1–10
Mohapatra RN, Chandra P (1983) Degree of approximation of functions in the Hölder metric. Acta Math Hung 41(1–2):67–76
Mursaleen M (2014) Applied summability methods. Springer, New York
Mursaleen M, Ahmad R (2013) Korovkin type approximation theorem through statistical lacunary summability. Iran J Sci Technol 37A2:99–102
Mursaleen M, Mohiuddine SA (2014) Convergence methods for double sequences and applications. Springer, New York
Prössdorf S (1975) Zur konvergenz der Fourier reihen Hölder steliger Funktionen. Math Nachr 69:7–14
Singh T (1992a) Degree of approximation of functions in a normed space. Publ Math Debrecen 40(3–4):261–267
Singh T (1992b) Approximation to functions in the Hölder metric. Proc Nat Acad Sci India 62(A):224–233
Singh T, Mahajan P (2008) Error bound of periodic signals in the Hölder metric. Int J Math Sci 2008:9
Yang J (2015) Norm convergent partial sums of Taylor series. Bull Korean Math Soc 52(5):1729–1735
Zygmund A (2002) Trigonometric series, 3rd edn. Cambridge Univ. Press, London
Acknowledgements
The authors would like to express their deep gratitude to the anonymous learned referee(s) and the editor for their valuable suggestions and constructive comments, which resulted in the subsequent improvement of this article. Special thanks are due to Dr. F. Moore Editor in Chief & Editors of Iranian Journal of Science and Technology (Sciences), for their kind cooperation, kindness during communication and for their efforts to send the reports of the manuscript timely. The authors are also grateful to all the editorial board members and reviewers of this prestigious journal, i.e., Iranian Journal of Science and Technology (Sciences). The first author acknowledges the Ministry of Human Resource Development, New Delhi, India for supporting this research article. The second author VNM acknowledges that this project was supported by the Cumulative Professional Development Allowance (CPDA), SVNIT, Surat (Gujarat), India. Authors carried out the proof. Each author contributed equally in the development of the manuscript. All the authors conceived the study and participated in its design and coordination. Authors read and approved the final manuscript. The authors declare that there is no conflict of interests regarding the publication of this paper.
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Khatri, K., Mishra, V.N. Degree of Approximation by the \( \left( {T.\,E^{\,1} } \right) \) Means of Conjugate Series of Fourier Series in the Hölder Metric. Iran J Sci Technol Trans Sci 43, 1591–1599 (2019). https://doi.org/10.1007/s40995-017-0272-3
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DOI: https://doi.org/10.1007/s40995-017-0272-3
Keywords
- Conjugate series of Fourier series
- Degree of approximation
- Hölder metric
- Matrix summability
- Product summability