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# exp, expf

Visual Studio 2005

Calculates the exponential.

```
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.

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.

C++ allows overloading, so you can call overloads of exp. In a C program, exp always takes and returns a double.

exp, expf

<math.h>

ANSI, Windows 95, Windows 98, Windows 98 Second Edition, Windows Millennium Edition, Windows NT 4.0, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003

For additional compatibility information, see Compatibility in the Introduction.

```// 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 );
}
```

#### Output

`exp( 2.302585 ) = 10.000000`

#### Reference

Floating-Point Support
log, logf, log10, log10f

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