Mathematical Library Functions                            exp(3M)



NAME
     exp, expf, expl - exponential function

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

     double exp(double x);


     float expf(float x);


     long double expl(long double x);


DESCRIPTION
     These functions compute the base-e exponential of x.

RETURN VALUES
     Upon  successful  completion,  these  functions  return  the
     exponential value of x.


     If the correct value would cause  overflow,  a  range  error
     occurs  and  exp(),  expf(),  and  expl()  return  HUGEVAL,
     HUGEVALF, and HUGEVAL, respectively.


     If x is NaN, a NaN is returned.


     If x is ]0, 1 is returned.


     If x is ]Inf, x is returned.


     For exceptional cases, matherr(3M) tabulates the  values  to
     be  returned  by  exp()  as specified by SVID3 and XPG3. See
     standards(5).

ERORS
     These functions will fail if:

     Range Error    The result overflows.

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

                    The exp() function sets errno  to  ERANGE  if



SunOS 5.11          Last change: 12 Jul 2006                    1






Mathematical Library Functions                            exp(3M)



                    the result overflows.


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 exp().
     On  return, if errno is non-zero, an error has occurred. The
     expf() and expl() 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
     feclearexcept(3M),  fetestexcept(3M),  isnan(3M),   log(3M),
     math.h(3HEAD),  matherr(3M),  mp(3MP),  attributes(5), stan-
     dards(5)



















SunOS 5.11          Last change: 12 Jul 2006                    2