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exp(3) — Linux manual page

exp(3)                   Library Functions Manualexp(3)

NAME        top

       exp, expf, expl - base-e exponential function

LIBRARY        top

       Math library (libm,-lm)

SYNOPSIS        top

#include <math.h>double exp(doublex);float expf(floatx);long double expl(long doublex);   Feature Test Macro Requirements for glibc (seefeature_test_macros(7)):expf(),expl():           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L               || /* Since glibc 2.19: */ _DEFAULT_SOURCE               || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION        top

       These functions return the value of e (the base of natural       logarithms) raised to the power ofx.

RETURN VALUE        top

       On success, these functions return the exponential value ofx.       Ifx is a NaN, a NaN is returned.       Ifx is positive infinity, positive infinity is returned.       Ifx 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        top

       Seemath_error(7) for information on how to determine whether an       error has occurred when calling these functions.       The following errors can occur:       Range error, overflowerrno is set toERANGE.  An overflow floating-point              exception (FE_OVERFLOW) is raised.       Range error, underflowerrno is set toERANGE.  An underflow floating-point              exception (FE_UNDERFLOW) is raised.

ATTRIBUTES        top

       For an explanation of the terms used in this section, seeattributes(7).       ┌──────────────────────────────────────┬───────────────┬─────────┐       │Interface│Attribute│Value│       ├──────────────────────────────────────┼───────────────┼─────────┤       │exp(),expf(),expl()                │ Thread safety │ MT-Safe │       └──────────────────────────────────────┴───────────────┴─────────┘

STANDARDS        top

       C11, POSIX.1-2008.

HISTORY        top

       C99, POSIX.1-2001.       The variant returningdouble also conforms to SVr4, 4.3BSD, C89.

SEE ALSO        top

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

COLOPHON        top

       This page is part of theman-pages (Linux kernel and C library       user-space interface documentation) project.  Information about       the project can be found at        ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report       for this manual page, see       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.       This page was obtained from the tarball man-pages-6.15.tar.gz       fetched from       ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on       2025-08-11.  If you discover any rendering problems in this HTML       version of the page, or you believe there is a better or more up-       to-date source for the page, or you have corrections or       improvements to the information in this COLOPHON (which isnot       part of the original manual page), send a mail to       man-pages@man7.orgLinux man-pages 6.15            2025-05-17exp(3)

Pages that refer to this page:erf(3), erfc(3), exp10(3), exp2(3), expm1(3), log1p(3)

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