# y0(3m) [ultrix man page]

```bessel(3m)																bessel(3m)

Name
j0, j1, jn, y0, y1, yn - bessel functions

Syntax
#include <math.h>

double j0(x)
double x;

double j1(x)
double x;

double jn(n,x)
double x;

double y0(x)
double x;

double y1(x)
double x;

double yn(n,x)
double x;

Description
These functions calculate bessel functions of the first and second kinds for real arguments and integer orders.

Return Values
Negative arguments cause and to return NaN.  Arguments too large in magnitude cause and to return NaN.

Arguments too large in magnitude cause and to return zero.

Environment
When  your program is compiled using the System V environment, nonpositive arguments cause and to return the value HUGE and to set errno to
EDOM.  In addition, a message indicating DOMAIN error is printed on the standard error output.

Arguments too large in magnitude cause and to return zero and to set errno to ERANGE.  In addition, a message  indicating  TLOSS  error	is
printed on the standard error output.

These error-handling procedures may be changed with the function.

math(3m)

RISC								bessel(3m)```

## Check Out this Related Man Page

```bessel(3)						     Library Functions Manual							 bessel(3)

NAME
bessel, j0, j1, jn, y0, y1, yn - Compute Bessel functions

LIBRARY
Math Library (libm.a)

SYNOPSIS
#include <math.h>

double  j0   (double  x); float	j0f (float  x); long double j0l (long double x); double j1  (double x); float  j1f (float  x); long double
j1l (long double x); double jn  (int n, double x); float  jnf (int n, float  x); long double jnl  (int n, long double x); double y0   (dou-
ble  x); float  y0f (float  x); long double y0l (long double x); double y1  (double x); float  y1f (float  x); long double y1l (long double
x); double yn  (int n, double x); float	ynf   (int n, float  x); long double ynl  (int n, long double x);

STANDARDS
Interfaces documented on this reference page conform to industry standards as follows:

j0():  XPG4

j1():  XPG4

jn():  XPG4

y0():  XPG4

y1():  XPG4

yn():  XPG4

DESCRIPTION
The j0(), j0f(), j0l(), j1(), j1f(), and j1l() functions return the value of the Bessel function of the first kind of orders 0  (zero)  and
1, respectively.

The jn(), jnf(), and jnl() functions return the value of the Bessel function of the first kind of order n.

The y0(), y0f(), y0l(), y1(), y1f(), and y1l() functions return the value of the Bessel functions of the second kind of orders 0 (zero) and
1, respectively.

The yn(), ynf(), and ynl()  functions return the value of the Bessel function of the second kind of order n.

The following table describes function behavior in response to exceptional arguments:

--------------------------------------------------------------
Function 	     Exceptional Argument   Routine Behavior
--------------------------------------------------------------
j0(), j1(), jn()      None		    N/A
j0f(), j1f(), jnf()   None		    N/A
j0l(), j1l(), jnl()   None		    N/A
y0(), y1(), yn()      x < 0		    Invalid argument
y0f(), y1f(), ynf()   x < 0		    Invalid argument
y0l(), y1l(), ynl()   x < 0		    Invalid argument
y0(), y1(), yn()      x = 0		    Overflow
y0f(), y1f(), ynf()   x = 0		    Overflow
y0l(), y1l(), ynl()   x = 0		    Overflow
--------------------------------------------------------------

The j1() and jn() functions can result in an underflow as x gets small.	The largest value of x for which this occurs is a function of n.

The y1() and yn() functions can result in an overflow as x gets small.  The largest value of x for which this occurs is a function of n.

delim off

bessel(3)```
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