sqrt()

calculate the nonnegative square root of a positive number

Synopsis:

#include <math.h>
double sqrt( double x );

Description:

The sqrt() function computes the nonnegative square root of x. A domain error occurs if the argument is negative.

Returns:

The nonnegative square root.

When the argument is outside the permissible range, the matherr() function is called. Unless the default matherr() function is replaced, it will set the global variable errno to EDOM, and print a "DOMAIN error" diagnostic message using the stderr stream.

Examples:

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

void main()
  {
    printf( "%f\n", sqrt(.5) );
  }

produces the output:

0.707107

Classification:

ANSI

See also:

errno, exp(), log(), pow(), matherr()