Condividi tramite


sqrt, sqrtf

Calculates the square root.

double sqrt(
   double x 
);
float sqrt(
   float x 
);  // C++ only
long double sqrt(
   long double x
);  // C++ only
float sqrtf(
   float x 
);

Parameters

  • x
    Nonnegative floating-point value

Remarks

C++ allows overloading, so users can call overloads of sqrt that take float or long double types. In a C program, sqrt always takes and returns double.

Return Value

The sqrt function returns the square-root of x. If x is negative, sqrt returns an indefinite, by default.

Input

SEH Exception

Matherr Exception

± QNAN,IND

none

_DOMAIN

- ∞

INVALID

_DOMAIN

x>0

INVALID

_DOMAIN

Requirements

Routine

Required header

sqrt, sqrtf

<math.h>

For additional compatibility information, see Compatibility in the Introduction.

Example

// crt_sqrt.c
// This program calculates a square root.

#include <math.h>
#include <stdio.h>
#include <stdlib.h>

int main( void )
{
   double question = 45.35, answer;

   answer = sqrt( question );
   if( question < 0 )
      printf( "Error: sqrt returns %.2f\n, answer" );
   else
      printf( "The square root of %.2f is %.2f\n", question, answer );
}
The square root of 45.35 is 6.73

.NET Framework Equivalent

System::Math::Sqrt

See Also

Reference

Floating-Point Support

exp, expf

log, logf, log10, log10f

pow, powf

_CIsqrt