CBRT(3P) POSIX Programmer's Manual CBRT(3P)PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the corresponding
Linux manual page for details of Linux behavior), or the interface may
not be implemented on Linux.
cbrt, cbrtf, cbrtl — cube root functions
double cbrt(double x);
float cbrtf(float x);
long double cbrtl(long double x);
The functionality described on this reference page is aligned with the
ISO C standard. Any conflict between the requirements described here
and the ISO C standard is unintentional. This volume of POSIX.1‐2008
defers to the ISO C standard.
These functions shall compute the real cube root of their argument x.
Upon successful completion, these functions shall return the cube root
If x is NaN, a NaN shall be returned.
If x is ±0 or ±Inf, x shall be returned.
No errors are defined.
The following sections are informative.
For some applications, a true cube root function, which returns nega‐
tive results for negative arguments, is more appropriate than pow(x,
1.0/3.0), which returns a NaN for x less than 0.
The Base Definitions volume of POSIX.1‐2008, <math.h>
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the source
files to man page format. To report such errors, see https://www.ker‐
IEEE/The Open Group 2013 CBRT(3P)