exp-expf.md

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exp, expf, expl | Microsoft Docs		11/04/2016			cpp-standard-libraries		article	expf expl exp	msvcrt.dll msvcr80.dll msvcr90.dll msvcr100.dll msvcr100_clr0400.dll msvcr110.dll msvcr110_clr0400.dll msvcr120.dll msvcr120_clr0400.dll ucrtbase.dll api-ms-win-crt-math-l1-1-0.dll	DLLExport	_expl expf expl exp	C++	exponential calculations expf function expl function calculating exponentials exp function	7070016d-1143-407e-9e9a-6b059bb88867	13	corob-msft	corob	ghogen

exp, expf, expl

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  
);  
long double expl(  
   long double x  
);  

Parameters

x
The floating-point value to exponentiate the natural logarithm base e by.

Return Value

The exp functions return the exponential value of the floating-point parameter, x, if successful. That is, the result is e^x, where e is the base of the natural logarithm. On overflow, the function returns INF (infinity) and on underflow, exp returns 0.

Input	SEH Exception	Matherr Exception
± Quiet NaN, indeterminate	None	_DOMAIN
± Infinity	INVALID	_DOMAIN
x ≥ 7.097827e+002	INEXACT+OVERFLOW	OVERFLOW
X ≤ -7.083964e+002	INEXACT+UNDERFLOW	UNDERFLOW

The exp function 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 that take a float or long double argument. In a C program, exp always takes and returns a double.

Requirements

Function	Required C header	Required C++ header
exp, expf	<math.h>	<cmath> or <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  

See Also

Floating-Point Support
log, logf, log10, log10f
_CIexp