expf(3) - phpMan

EXP(3)                     Linux Programmer's Manual                    EXP(3)

NAME
       exp, expf, expl - base-e exponential function
SYNOPSIS
       #include <math.h>
       double exp(double x);
       float expf(float x);
       long double expl(long double x);
       Link with -lm.
   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
       expf(), expl():
           _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 ||
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;
           or cc -std=c99
DESCRIPTION
       The exp() function returns the value of e (the base  of  natural  loga-
       rithms) raised to the power of x.
RETURN VALUE
       On success, these functions return the exponential value of x.
       If x is a NaN, a NaN is returned.
       If x is positive infinity, positive infinity is returned.
       If x is negative infinity, +0 is returned.
       If the result underflows, a range error occurs, and zero is returned.
       If the result overflows, a range error occurs, and the functions return
       +HUGE_VAL, +HUGE_VALF, or +HUGE_VALL, respectively.
ERRORS
       See math_error(7) for information on how to determine whether an  error
       has occurred when calling these functions.
       The following errors can occur:
       Range error, overflow
              errno  is  set  to ERANGE.  An overflow floating-point exception
              (FE_OVERFLOW) is raised.
       Range error, underflow
              errno is set to ERANGE.  An underflow  floating-point  exception
              (FE_UNDERFLOW) is raised.
CONFORMING TO
       C99, POSIX.1-2001.  The variant returning double also conforms to SVr4,
       4.3BSD, C89.
SEE ALSO
       cbrt(3), cexp(3), exp10(3), exp2(3), sqrt(3)
COLOPHON
       This page is part of release 3.53 of the Linux  man-pages  project.   A
       description  of  the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

                                  2010-09-20                            EXP(3)