exp, expf, expl - base-e exponential function
#include <math.h> double exp(double x); float expf(float x); long double expl(long double x);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
These functions return the value of e (the base of natural
logarithms) raised to the power of
On success, these functions return the exponential value of
x is a NaN, a NaN is returned.
x is positive infinity, positive infinity is
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.
See math_error(7) for information on how to determine whether an error has occurred when calling these functions.
The following errors can occur:
errno is set to ERANGE. An overflow
floating-point exception (FE_OVERFLOW) is raised.
errno is set to ERANGE. An underflow
floating-point exception (FE_UNDERFLOW) is raised.
C99, POSIX.1-2001, POSIX.1-2008.
The variant returning
double also conforms to SVr4, 4.3BSD,
This page is part of release 5.10 of the Linux
project. A description of the project, information about reporting bugs,
and the latest version of this page, can be found at