Subrahmanya, M.R.
Topics on Simultaneous best approximation - 1974 - iv; 92p.
1974
In 1968 Rivlin posed a problem on Algebraic Polynomial; "Characterise those n-tuples of algebraic polynomials such that the degree of Pj is j for j = 0,1,2,..., n-1., for which there exists a real valued continuous function f defined on a closed and finite interval, [a,b] so that the polynomial of best approximation of degree j for f in the sense of Chebyshev, is Pj, j = 0,1,2, ... , n-1". He suggested the necessary condition that, " Suppose there exists a continuous real valued function f defined on [a,b], such that Pj is the polynomial of best approximation, to f of degree j. Then for each pair of indices, i, k, 0 < (or) = i < K < (or) = (n-1). The polynomial Pi - Pk is either identically zero or changes sign atleast (i+1) distinct points in [a,b]. This thesis study the problem for algebraic polynomials and also for General Chebyshev system, and obtain necessary and sufficient conditions. Further various related problems are also discussed.
Mathematics
Algebraic Polynomials General Chebyshev's System
UNM Th-18
Topics on Simultaneous best approximation - 1974 - iv; 92p.
1974
In 1968 Rivlin posed a problem on Algebraic Polynomial; "Characterise those n-tuples of algebraic polynomials such that the degree of Pj is j for j = 0,1,2,..., n-1., for which there exists a real valued continuous function f defined on a closed and finite interval, [a,b] so that the polynomial of best approximation of degree j for f in the sense of Chebyshev, is Pj, j = 0,1,2, ... , n-1". He suggested the necessary condition that, " Suppose there exists a continuous real valued function f defined on [a,b], such that Pj is the polynomial of best approximation, to f of degree j. Then for each pair of indices, i, k, 0 < (or) = i < K < (or) = (n-1). The polynomial Pi - Pk is either identically zero or changes sign atleast (i+1) distinct points in [a,b]. This thesis study the problem for algebraic polynomials and also for General Chebyshev system, and obtain necessary and sufficient conditions. Further various related problems are also discussed.
Mathematics
Algebraic Polynomials General Chebyshev's System
UNM Th-18