33.3 Graphics33.5 Limiting Forms for Small \rho, Small |\eta|, or Large \ell

§33.4 Recurrence Relations and Derivatives

For \ell=1,2,3,\dots, let

33.4.1
R_{\ell}=\sqrt{1+\dfrac{\eta^{2}}{\ell^{2}}},
S_{\ell}=\dfrac{\ell}{\rho}+\dfrac{\eta}{\ell},
T_{\ell}=S_{\ell}+S_{{\ell+1}}.

Then, with X_{\ell} denoting any of \mathop{F_{{\ell}}\/}\nolimits\!\left(\eta,\rho\right), \mathop{G_{{\ell}}\/}\nolimits\!\left(\eta,\rho\right), or \mathop{{H^{{\pm}}_{{\ell}}}\/}\nolimits\!\left(\eta,\rho\right),

33.4.2R_{\ell}X_{{\ell-1}}-T_{\ell}X_{{\ell}}+R_{{\ell+1}}X_{{\ell+1}}=0,\ell\geq 1,
33.4.3X_{\ell}^{{\prime}}=R_{\ell}X_{{\ell-1}}-S_{\ell}X_{\ell},\ell\geq 1,
33.4.4X_{\ell}^{{\prime}}=S_{{\ell+1}}X_{\ell}-R_{{\ell+1}}X_{{\ell+1}},\ell\geq 0.