# FreeBSD Manual Pages

```J0(3)			   Linux Programmer's Manual			 J0(3)

NAME
j0,  j0f,  j0l, j1, j1f,	j1l, jn, jnf, jnl, y0, y0f, y0l, y1, y1f, y1l,
yn, ynf,	ynl - Bessel functions

SYNOPSIS
#include	<math.h>

double j0(double	x);
double j1(double	x);
double jn(int n,	double x);
double y0(double	x);
double y1(double	x);
double yn(int n,	double x);

float j0f(float x);
float j1f(float x);
float jnf(int n,	float x);
float y0f(float x);
float y1f(float x);
float ynf(int n,	float x);

long double j0l(long double x);
long double j1l(long double x);
long double jnl(int n, long double x);
long double y0l(long double x);
long double y1l(long double x);
long double ynl(int n, long double x);

DESCRIPTION
The j0()	and j1() functions return Bessel functions of x	of  the	 first
kind  of	 orders	 0 and 1, respectively.	 The jn() function returns the
Bessel function of x of the first kind of order n.

The y0()	and y1() functions return Bessel functions of x	of the	second
kind  of	 orders	 0 and 1, respectively.	 The yn() function returns the
Bessel function of x of the second kind of order	n.

For the functions y0(), y1() and	yn(), the value	of x must be positive.
For negative values of x, these functions return	-HUGE_VAL.

The  j0f() etc. and j0l() etc. functions	are versions that take and re-
turn float and long double values, respectively.

CONFORMING TO
The functions returning double conform to SVID 3, BSD 4.3, XPG4,	 POSIX
1003.1-2001. The	other functions	exist by analogy, and exist on several
platforms.

BUGS
There are errors	of up to 2e-16 in the values returned  by  j0(),  j1()
and jn()	for values of x	between	-8 and 8.

2002-08-25				 J0(3)
```

NAME | SYNOPSIS | DESCRIPTION | CONFORMING TO | BUGS

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