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).
       ┌───────────────────────┬───────────────┬─────────┐
       │ Interface             │ Attribute     │ Value   │
       ├───────────────────────┼───────────────┼─────────┤
       │ exp(), expf(), expl() │ 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

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       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)