|EXP(3)||Linux Programmer's Manual||EXP(3)|
NAME¶exp, expf, expl - base-e exponential function
#include <math.h> double exp(double x);Link with -lm.float expf(float x);long double expl(long double x);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;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 3.74 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 http://www.kernel.org/doc/man-pages/.