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():
           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION
       These  functions return the value of e (the base of natural logarithms)
       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.

ATTRIBUTES
       For  an  explanation  of  the  terms  used   in   this   section,   see
       attributes(7).

       allbox; lbw21 lb lb l l l.  Interface Attribute Value T{ exp(), expf(),
       expl() T}   Thread safety  MT-Safe

CONFORMING TO
       C99, POSIX.1-2001, POSIX.1-2008.

       The variant returning double also conforms to SVr4, 4.3BSD, C89.

SEE ALSO
       cbrt(3), cexp(3), exp10(3), exp2(3), expm1(3), sqrt(3)

COLOPHON
       This page is part of release 4.16 of the Linux  man-pages  project.   A
       description  of  the project, information about reporting bugs, and the
       latest    version    of    this    page,    can     be     found     at
       https://www.kernel.org/doc/man-pages/.



                                  2017-09-15                            EXP(3)