# FreeBSD Manual Pages

```J0(3)			 BSD Library Functions Manual			 J0(3)

NAME
j0, j0f, j1, j1f, jn, jnf,	y0, y0f, y1, y1f, yn, ynf -- Bessel functions
of	first and second kind

LIBRARY
Math Library (libm, -lm)

SYNOPSIS
#include <math.h>

double
j0(double x);

float
j0f(float x);

double
j1(double x);

float
j1f(float x);

double
jn(int n, double x);

float
jnf(int n,	float x);

double
y0(double x);

float
y0f(float x);

double
y1(double x);

float
y1f(float x);

double
yn(int n, double x);

float
ynf(int n,	float x);

DESCRIPTION
The functions j0(), j0f(),	j1() and j1f() compute the Bessel function of
the first kind of the order 0 and the order 1, respectively, for the real
value x; the functions jn() and jnf() compute the Bessel function of the
first kind	of the integer order n for the real value x.

The functions y0(), y0f(),	y1(), and y1f()	compute	the linearly indepen-
dent Bessel function of the second	kind of	the order 0 and	the order 1,
respectively, for the positive real value x; the functions	yn() and ynf()
compute the Bessel	function of the	second kind for	the integer order n
for the positive real value x.

RETURN VALUES
If	these functions	are successful,	the computed value is returned.