ORTHOGONALITY OF RESIDUAL POLYNOMIALS USED IN MINIMAX POLYNOMIAL PRECONDITIONING

A polynomial from P-n, P-n, the set of polynomials of degree less or equal n, is called minimax residual polynomial on a compact set E subset of R if it has least max-norm on E among all polynomials from P-n with fixed lowest coefficient or with two fixed lowest coefficients. It is pointed out that recently published results on orthogonality of minimax residual polynomials on two intervals by H. Jiang [5] are direct consequences of results of the author on orthogonality properties of classical minimal polynomials with respect to the max-norm. In fact, as is demonstrated, even more general and stronger results hold.