**jn**

first kind
SYNOPSIS
#include <math.h>
double j0(double x);
double j1(double x);
double jn(int n, double x);
float j0f(float x);
float j1f(float x);
float jnf(int n, float x);
long double j0l(long double x);
long double j1l(long double x);
long double jnl(int n, long double x);
Link with -lm.
Feature Test Macro Requirements for glibc (see **feature_test_macros(7)**):
j0(), j1(), jn():
_SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE
j0f(), j0l(), j1f(), j1l(), jnf(), jnl():
_SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 600
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 j0f() etc. and j0l() etc. functions are versions that take and
return float and long double values, respectively.
RETURN VALUE
On success, these functions return the appropriate Bessel value of the
first kind for x.
If x is a NaN, a NaN is returned.
If x is too large in magnitude, or the result underflows, a range error
occurs, and the return value is 0.
ERRORS
See **math_error(7)** for information on how to determine whether an error
has occurred when calling these functions.
The following errors can occur:
Range error: result underflow, or x is too large in magnitude
errno is set to ERANGE.
These functions do not raise exceptions for **fetestexcept(3)**.
This page is part of release 3.54 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
2010-09-20 **J0(3)**

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