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():

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¶

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