exp, expf
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Calculates the exponential.
Syntax
double exp(
double x
);
float exp(
float x
); // C++ only
long double exp(
long double x
); // C++ only
float expf(
float x
);
Parameters
x
Floating-point value.
Return Value
The exp function returns the exponential value of the floating-point parameter, x, if successful. That is, the result is e to the power x, where e is the base of the natural logarithm. On overflow, the function returns INF (infinite) and on underflow, exp returns 0.
| Input | SEH Exception | Matherr Exception |
|---|---|---|
| ± QNAN,IND | None | _DOMAIN |
| ± ∞ | INVALID | _DOMAIN |
| x ≥ 7.097827e+002 | INEXACT+OVERFLOW | OVERFLOW |
| X ≤ -7.083964e+002 | INEXACT+UNDERFLOW | UNDERFLOW |
exp has an implementation that uses Streaming SIMD Extensions 2 (SSE2). See _set_SSE2_enable for information and restrictions on using the SSE2 implementation.
Remarks
C++ allows overloading, so you can call overloads of exp. In a C program, exp always takes and returns a double.
Requirements
| Function | Required header |
|---|---|
exp, expf |
<math.h> |
For additional compatibility information, see Compatibility in the Introduction.
Example
// crt_exp.c
#include <math.h>
#include <stdio.h>
int main( void )
{
double x = 2.302585093, y;
y = exp( x );
printf( "exp( %f ) = %f\n", x, y );
}
exp( 2.302585 ) = 10.000000