In this paper we introduce
and study a pair of biorthogonal polynomials that are suggested by the
classical Jacobi polynomials. Let α > −1, β > −1 and Jn(α,β,k;x) and
Kn(α,β,k;x), n = 0,1,2,⋯ be respectively the polynomials of degree n in xk and x,
where x is real, k is a positive integer such that these two polynomial sets satisfy
biorthogonality conditions with respect to the weight function (1 − x)α(1 + x)β,
namely
∫−11(1 − x)α(1 + x)βJn(α,β,k;x)xidx is
(1)
and
∫−11(1 − x)α(1 + x)βKn(α,β,k;x)(1 − x)kidx is
(2)
It follows from (1) and (2) that
∫−11(1 − x)α(1 + x)βJn(α,β,k;x)Km(α,β,k;x)dx is
(3)
and conversely.
For k = 1 both these sets are reduced to the Jacobi polynomial sets. We obtain
generating functions, recurrence relations for both these sets and explicitly show that
they satisfy biorthogonality conditions.