SAS/C Library Reference, Vol. 1

sinh -- Compute the Hyperbolic Sine

SYNOPSIS

 #include <math.h>

 double sinh(double x);

DESCRIPTION

sinh computes the hyperbolic sine of its argument x, expressed by this relation:

 r = (e**x - e**x)/2

RETURN VALUE

sinh returns the principal value of the hyperbolic sine of the argument x, if this value is defined and computable. The return value is a double-precision, floating-point number.

DIAGNOSTICS

For a positive value of x that is too large, the sinh function returns HUGE_VAL. For a negative x value that is too large, sinh returns -HUGE_VAL. In both cases, the run-time library writes an error message to stderr (the standard error file).

If an error occurs in sinh, the _matherr routine is called. You can supply your own version of _matherr to suppress the diagnostic message or modify the value returned.

EXAMPLE

This example computes the hyperbolic cosecant of a value:

  #include <math.h>
  #include <stdio.h>

  #define YRANG 1.30

  main()
  {
     double cosec_h;

        /* The hyperbolic cosecant of a value is 1      */
        /* divided by the hyperbolic sine of the value. */
     cosec_h = 1 / sinh(YRANG);
     printf("1 / sinh(%f) = %fn", YRANG, cosec_h);
  }

RELATED FUNCTIONS

cosh, _matherr, tanh