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; or cc -std=c99
DESCRIPTION
The exp() function returns 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.
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 3.24 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/.
2008-08-05