SQRT(3)                     BSD Programmer's Manual                    SQRT(3)

NAME
     cbrt, sqrt - cube root and square root functions

SYNOPSIS
     #include <math.h>

     double
     cbrt(double x)

     double
     sqrt(double x)

DESCRIPTION
     The cbrt() function computes the cube root of x.

     The sqrt() computes the non-negative square root of x.

RETURN VALUES
     The cbrt() function returns the requested cube root.  The sqrt() function
     returns the requested square root unless an error occurs.  On the VAX or
     Tahoe processor an attempt to take the sqrt() of negative x causes an er-
     ror; in this event, the global variable errno is set to EDOM and a re-
     served operand fault is generated.

ERROR (due to Roundoff etc.)
     The cbrt() function is accurate to within 0.7 ulps.

     The sqrt() function 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 de-
     fault mode (round-to-nearest).  An ulp is one Unit in the Last Place car-
     ried.

SEE ALSO
     math(3),  infnan(3)

STANDARDS
     The sqrt function conforms to ANSI C3.159-1989 (``ANSI C'').

HISTORY
     The cbrt function appeared in 4.3BSD.

BSDI BSD/386                    March 26, 1993                               1