'\" t .\" Copyright 1995 Jim Van Zandt .\" .\" SPDX-License-Identifier: Linux-man-pages-copyleft .\" .\" changed `square root' into `cube root' - aeb, 950919 .\" .\" Modified 2002-07-27 Walter Harms .\" (walter.harms@informatik.uni-oldenburg.de) .\" .TH cbrt 3 2023-03-30 "Linux man-pages 6.04" .SH NAME cbrt, cbrtf, cbrtl \- cube root function .SH LIBRARY Math library .RI ( libm ", " \-lm ) .SH SYNOPSIS .nf .B #include .PP .BI "double cbrt(double " x ); .BI "float cbrtf(float " x ); .BI "long double cbrtl(long double " x ); .fi .PP .RS -4 Feature Test Macro Requirements for glibc (see .BR feature_test_macros (7)): .RE .PP .BR cbrt (): .nf _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 500 .\" || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE .fi .PP .BR cbrtf (), .BR cbrtl (): .nf _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE .fi .SH DESCRIPTION These functions return the (real) cube root of .IR x . This function cannot fail; every representable real value has a representable real cube root. .SH RETURN VALUE These functions return the cube root of .IR x . .PP If .I x is +0, \-0, positive infinity, negative infinity, or NaN, .I x is returned. .SH ERRORS No errors occur. .SH ATTRIBUTES For an explanation of the terms used in this section, see .BR attributes (7). .ad l .nh .TS allbox; lbx lb lb l l l. Interface Attribute Value T{ .BR cbrt (), .BR cbrtf (), .BR cbrtl () T} Thread safety MT-Safe .TE .hy .ad .sp 1 .SH STANDARDS C11, POSIX.1-2008. .SH HISTORY C99, POSIX.1-2001. .\" .BR cbrt () .\" was a GNU extension. It is now a C99 requirement. .SH SEE ALSO .BR pow (3), .BR sqrt (3)