For large values of the parameters in the , , and symbols, different asymptotic forms are obtained depending on which parameters are large. For example,
and the symbol denotes a quantity that tends to zero as the parameters tend to infinity, as in §2.1(i).
Semiclassical (WKBJ) approximations in terms of trigonometric or exponential functions are given in Varshalovich et al. (1988, §§8.9, 9.9, 10.7). Uniform approximations in terms of Airy functions for the and symbols are given in Schulten and Gordon (1975b). For approximations for the , , and symbols with error bounds see Flude (1998), Chen et al. (1999), and Watson (1999): these references also cite earlier work.