Returns the square root of its argument.

    Format

      #include  <math.h>

      double sqrt  (double x);

      float sqrtf  (float x); (Integrity servers, Alpha)

      long double sqrtl  (long double x); (Integrity servers, Alpha)

1 - Argument

 x

    A real number.

2 - Return Values

    val                The square root of x, if x is nonnegative.
    0                  x is negative; errno is set to EDOM.
    NaN                x is NaN; errno is set to EDOM.