**NAME**

cbrt, cbrtf, cbrtl - cube root function

**SYNOPSIS**

**#include** **<math.h>**
**double** **cbrt(double** __x__**);**
**float** **cbrtf(float** __x__**);**
**long** **double** **cbrtl(long** **double** __x__**);**
Link with __-lm__.
Feature Test Macro Requirements for glibc (see **feature_test_macros**(7)):
**cbrt**(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 ||
_ISOC99_SOURCE; or __cc__ __-std=c99__
**cbrtf**(), **cbrtl**(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600
|| _ISOC99_SOURCE; or __cc__ __-std=c99__

**DESCRIPTION**

The **cbrt**() function returns the (real) cube root of __x__. This function
cannot fail; every representable real value has a representable real
cube root.

**RETURN** **VALUE**

These functions return the cube root of __x__.
If __x__ is +0, -0, positive infinity, negative infinity, or NaN, __x__ is
returned.

**ERRORS**

No errors occur.

**CONFORMING** **TO**

C99, POSIX.1-2001.

**SEE ALSO**

**pow**(3), **sqrt**(3)

**COLOPHON**

This page is part of release 3.24 of the Linux __man-pages__ project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.