Resultants and discriminants of Chebyshev and related polynomials

Abstract

We show that the resultants with respect to x x of certain linear forms in Chebyshev polynomials with argument x x are again linear forms in Chebyshev polynomials. Their coefficients and arguments are certain rational functions of the coefficients of the original forms. We apply this to establish several related results involving resultants and discriminants of polynomials, including certain self-reciprocal quadrinomials.