double sph_bessel(unsigned n, double x);
float sph_besself(unsigned n, float x);
long double sph_bessell(unsigned n, long double x);
Effects: These functions compute the spherical Bessel functions of the first kind of their respective arguments n and x.
Returns: jn(x) = (π/2x)1/2 Jn + 1/2(x), for x ≥ 0 where n is n and x is x.
See also [sf.cmath.cyl_bessel_j].