libc.a reference
exp
Syntax
 #include <math.h>
double exp(double x);

Description
This function computes the exponential of x, e^x, where
e is the base of the natural system of logarithms, approximately
2.718281828.
Return Value
e to the x power. If the value of x is finite, but so
large in magnitude that its exponential cannot be accurately represented
by a double
, the return value is the nearest representable
double
(possibly, an Inf
), and errno
is set to
ERANGE
. If x is either a positive or a negative infinity,
the result is either +Inf
or zero, respectively, and errno
is not changed. If x is a NaN
, the return value is
NaN
and errno
is set to EDOM
.
Portability
ANSI/ISO C 
C89; C99

POSIX 
1003.21992; 1003.12001
