Mathematical Library Functions                           cosh(3M)



NAME
     cosh, coshf, coshl - hyperbolic cosine function

SYNOPSIS
     c99 [ flag... ] file... -lm [ library... ]
     #include 

     double cosh(double x);


     float coshf(float x);


     long double coshl(long double x);


DESCRIPTION
     These functions compute the hyperbolic cosine of their argu-
     ment x.

RETURN VALUES
     Upon  successful  completion,  these  functions  return  the
     hyperbolic cosine of x.


     If the correct value would cause  overflow,  a  range  error
     occurs  and cosh(), coshf(), and coshl() return the value of
     the macro HUGEVAL, HUGEVALF, and HUGEVAL, respectively.


     If x is NaN, a NaN is returned.


     If x is ]0, 1.0 is returned.


     If x is ]Inf, ]Inf is returned.


     For exceptional cases, matherr(3M) tabulates the  values  to
     be returned by cosh() as specified by SVID3 and XPG3.

ERORS
     These functions will fail if:

     Range Error    The result would cause an overflow.

                    If the integer expression (matherrhandling &
                    MATHEREXCEPT)  is  non-zero,  the  overflow
                    floating-point exception is raised.

                    The cosh() function sets errno to  ERANGE  if



SunOS 5.11          Last change: 12 Jul 2006                    1






Mathematical Library Functions                           cosh(3M)



                    the result would cause an overflow.


USAGE
     An application wanting to check for exceptions  should  call
     feclearexcept(FEALEXCEPT) before calling these functions.
     On  return,  if  fetestexcept(FEINVALID    FEDIVBYZERO  
     FEOVERFLOW    FEUNDERFLOW)  is non-zero, an exception has
     been raised. An application should either examine the return
     value  or check the floating point exception flags to detect
     exceptions.


     An application can  also  set  errno  to  0  before  calling
     cosh().  On  return,  if  errno  is  non-zero,  an error has
     occurred. The coshf()  and  coshl()  functions  do  not  set
     errno.

ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     
           ATRIBUTE TYPE               ATRIBUTE VALUE       
    
     Interface Stability          Standard                    
    
     MT-Level                     MT-Safe                     
    


SEE ALSO
     acosh(3M), feclearexcept(3M),  fetestexcept(3M),  isnan(3M),
     math.h(3HEAD),   matherr(3M),   sinh(3M),  tanh(3M),  attri-
     butes(5), standards(5)


















SunOS 5.11          Last change: 12 Jul 2006                    2