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exp |
Portability: | ISO/ANSI C conforming, UNIX compatible |
SYNOPSIS | |
DESCRIPTION | |
RETURN VALUE | |
DIAGNOSTICS | |
EXAMPLE | |
RELATED FUNCTIONS | |
SEE ALSO |
SYNOPSIS |
#include <math.h> double exp(double x);
DESCRIPTION |
exp
computes the exponential function of its argument
x
. The result is
e
to the
x
power, where
e
is the base of natural logarithms, 2.71828 . . ..
The exponential function is the inverse of the natural logarithm and is expressed by this relation:
x
is a double-precision,
floating-point number.
RETURN VALUE |
exp
returns the exponential function of its argument
x
, expressed as a double-precision, floating-point number.
DIAGNOSTICS |
If
x
is too large and the ensuing result is so large that it cannot be represented,
exp
returns
HUGE_VAL
. In this case, the run-time library writes an error message to the
standard error file (
stderr
).
If an error occurs in
exp
, the
_matherr
routine is called.
You can supply your own version of
_matherr
to suppress the diagnostic message or modify the value returned.
EXAMPLE |
#include <math.h> #include <stdio.h> #define XVAL 10.0 main() { double y; /* Compute exponent function. */ y = exp(-XVAL); printf("exp(-%f) = %f\n", XVAL, y); }
RELATED FUNCTIONS |
SEE ALSO |
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