bsd man page for sqrt

SQRT(3M)																  SQRT(3M)

NAME
       cbrt, sqrt - cube root, square root

SYNOPSIS
       #include <math.h>

       double cbrt(x)
       double x;

       double sqrt(x)
       double x;

DESCRIPTION
       Cbrt(x) returns the cube root of x.

       Sqrt(x) returns the square root of x.

DIAGNOSTICS
       On a VAX, sqrt(negative) returns the reserved operand and sets errno to EDOM .

ERROR (due to Roundoff etc.)
       Cbrt is accurate to within 0.7 ulps.
       Sqrt on a VAX is accurate to within 0.501 ulps.
       Sqrt on a machine that conforms to IEEE 754 is correctly rounded in accordance with the rounding mode in force; the error is less than half
       an ulp in the default mode (round-to-nearest).  An ulp is one Unit in the Last Place carried.

SEE ALSO
       math(3M), infnan(3M)

AUTHOR
       W. Kahan

4.3 Berkeley Distribution					   May 12, 1986 							  SQRT(3M)