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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 
);

x

Nonnegative floating-point value

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.

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

Routine

Required header

sqrt , sqrtf

<math.h>

For additional compatibility information, see Compatibility in the Introduction.

// 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 %f\n", answer );
   else
      printf( "The square root of %.2f is %.2f\n", question, answer );
}
The square root of 45.35 is 6.73
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