


      BESSEL(3M)                  (UNIX 5.0)                 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)
           int n;
           double x;

           double y0 (x)
           double x;

           double y1 (x)
           double x;

           double yn (n, x)
           int n;
           double x;

      DESCRIPTION
           J0 and j1 return Bessel functions of x of the first kind of
           orders 0 and 1 respectively.  Jn returns the Bessel function
           of x of the first kind of order n.

           Y0 and y1 return the Bessel functions of x of the second
           kind of orders 0 and 1 respectively.  Yn returns the Bessel
           function of x of the second kind of order n.  The value of x
           must be positive.

      DIAGNOSTICS
           Non-positive arguments cause y0, y1 and yn to return the
           value HUGE and to set errno to EDOM.  They also cause a
           message indicating DOMAIN error to be printed on the
           standard error output; the process will continue.

           These error-handling procedures may be changed with the
           function matherr(3M).

      SEE ALSO
           matherr(3M).








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