SQRT(3) BSD Library Functions Manual SQRT(3)NAME
cbrt, sqrt — cube root and square root functions
The cbrt() function computes the cube root of x.
The sqrt() computes the non-negative square root of x.
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
error; in this event, the global variable errno is set to EDOM and a
reserved 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
default mode (round-to-nearest). An ulp is one Unit in the Last Place
SEE ALSOmath(3), infnan(3)STANDARDS
The sqrt function conforms to ANSI X3.159-1989 (“ANSI C89”).
The cbrt function appeared in 4.3BSD.
BSD June 4, 1993 BSD