[sf.cmath.sph.bessel]

# 29 Numerics library [[numerics]](./#numerics)

## 29.7 Mathematical functions for floating-point types [[c.math]](c.math#sf.cmath.sph.bessel)

### 29.7.6 Mathematical special functions [[sf.cmath]](sf.cmath#sph.bessel)

#### 29.7.6.20 Spherical Bessel functions of the first kind [sf.cmath.sph.bessel]

[ð](#lib:sph_bessel)

`floating-point-type sph_bessel(unsigned n, floating-point-type x);
float        sph_besself(unsigned n, float x);
long double  sph_bessell(unsigned n, long double x);
`

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L10719)

*Effects*: These functions compute
the spherical Bessel functions of the first kind
of their respective argumentsn and x[.](#1.sentence-1)

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L10726)

*Returns*: jn(x),
where jn is given by Formula [29.40](#eq:sf.cmath.sph.bessel),n is n, andx is x[.](#2.sentence-1)

jn(x)=(Ï/2x)1/2Jn+1/2(x)Â , forÂ xâ¥0(29.40)

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L10736)

*Remarks*: The effect of calling each of these functions
is implementation-defined
if n >= 128[.](#3.sentence-1)

[4](#4)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L10742)

See also [[sf.cmath.cyl.bessel.j]](sf.cmath.cyl.bessel.j "29.7.6.9 Cylindrical Bessel functions of the first kind")[.](#4.sentence-1)
