bessel(3M)

NAME
     j0, j1, jn, y0, y1, yn, j0l, j1l, jnl, y0l, y1l, 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);
     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);

IMPLEMENTATION
     IRIX systems

DESCRIPTION
     j0 and j1 return Bessel functions of x of the first kind of orders
     zero and one, respectively.  jn returns the Bessel function of x of
     the first kind of order n.  j0l, j1l, and jnl are the long double
     versions of these functions.

     y0 and y1 return Bessel functions of x of the second kind of orders
     zero and one, respectively.  yn returns the Bessel function of x of
     the second kind of order n.  The value of x must be positive.  y0l,
     y1l, and ynl are the long double versions of these functions.

RETURN VALUES
     Functions in the standard math library libm.a are referred to as -lm
     versions. Those in math library libmx.a are referred to as -lmx
     versions, and those in the the BSD math library libm43.a are referred
     to as -lm43 versions.

     The -lm and -lmx versions always return the default Quiet NaN and set
     errno to EDOM when a NaN is used as an argument.  A NaN argument
     usually causes the -lm43 versions to return the same argument.  The
     -lm43 versions never set errno.

     The value of HUGE_VAL is IEEE Infinity.

     If the value of x is zero, y0, y1 and yn return the value -HUGE_VAL.

     The -lm and -lmx versions also set errno to ERANGE.

     Negative values of x cause y0, y1 and yn to return the default quiet
     NaN.  The -lm and -lmx versions also set errno to EDOM.

     Values of x which are too large cause y0, y1 and yn to return zero.
     The -lm and -lmx versions also set errno to ERANGE.

     Values of x too large in magnitude cause j0, j1 and jn to return zero.
     The -lm and -lmx versions also set errno to ERANGE.

SEE ALSO
     math(3M), matherr(3M)

     This man page is available only online.