14 Legendre and Related FunctionsReal Arguments

§14.11 Derivatives with Respect to Degree or Order

14.11.2 ν𝖰νμ(x)=12π2𝖯νμ(x)+πsin(μπ)sin(νπ)sin((ν+μ)π)𝖰νμ(x)12cot((ν+μ)π)𝖠νμ(x)+12csc((ν+μ)π)𝖠νμ(x),

where

14.11.3 𝖠νμ(x)=sin(νπ)(1+x1x)μ/2k=0(1212x)kΓ(kν)Γ(k+ν+1)k!Γ(kμ+1)(ψ(k+ν+1)ψ(kν)).

(14.11.1) holds if 𝖯νμ(x) is replaced by Pνμ(x), provided that the factor ((1+x)/(1x))μ/2 in (14.11.3) is replaced by ((x+1)/(x1))μ/2. (14.11.4) holds if 𝖯νμ(x), 𝖯ν(x), and 𝖰ν(x) are replaced by Pνμ(x), Pν(x), and Qν(x), respectively.

See also Szmytkowski (2006, 2009, 2011, 2012), Cohl (2010, 2011) and Magnus et al. (1966, pp. 177–178).