Jacobi polynomials

In mathematics, Jacobi polynomials (occasionally called hypergeometric polynomials) P(α, β)n(x) are a class of classical orthogonal polynomials. They are orthogonal with respect to the weight (1 − x)α(1 + x)β on the interval . The Gegenbauer polynomials, and thus also the Legendre, Zernike and Chebyshev polynomials, are special cases of the Jacobi polynomials. The Jacobi polynomials were introduced by Carl Gustav Jacob Jacobi. The Jacobi polynomials are defined via the hypergeometric function as follows: where ( α + 1 ) n {displaystyle (alpha +1)_{n}} is Pochhammer's symbol (for the rising factorial). In this case, the series for the hypergeometric function is finite, therefore one obtains the following equivalent expression: An equivalent definition is given by Rodrigues' formula: If α = β = 0 {displaystyle alpha =eta =0} , then it reduces to the Legendre polynomials: For real x the Jacobi polynomial can alternatively be written as and for integer n