EXPSection: Linux Programmer's Manual (3)
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NAMEexp, expf, expl - base-e exponential function
#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)):
DESCRIPTIONThe exp() function returns the value of e (the base of natural logarithms) raised to the power of x.
RETURN VALUEOn 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.
ERRORSSee 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 TOC99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD, C89.
SEE ALSOcbrt(3), cexp(3), exp10(3), exp2(3), sqrt(3)
COLOPHONThis page is part of release 3.21 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/.