cbrt, cbrtf, cbrtl — cube root function


#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)):


   || _XOPEN_SOURCE >= 500
   || /* Since glibc 2.19: */ _DEFAULT_SOURCE
   || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

cbrtf(), cbrtl():

   || /* Since glibc 2.19: */ _DEFAULT_SOURCE
   || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE


These functions return 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.


No errors occur.


For an explanation of the terms used in this section, see attributes(7).

Interface Attribute Value
cbrt(), cbrtf(), cbrtl() Thread safety MT-Safe

Conforming to

C99, POSIX.1-2001, POSIX.1-2008.

See Also

pow(3), sqrt(3)


This page is part of release 5.04 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

Referenced By

exp(3), exp10(3), exp2(3), log(3), log10(3), log2(3), pow(3), sqrt(3).

The man pages cbrtf(3) and cbrtl(3) are aliases of cbrt(3).

2017-09-15 GNU Linux Programmer's Manual