exp, expf

Article
2013-02-01

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.

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

.NET Framework Equivalent

System::Math::Exp

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