`cbrt.3p` ( 3 )

кубические корневые функции (cube root functions)

Пролог (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.

Имя (Name)

cbrt, cbrtf, cbrtl — cube root functions

Синопсис (Synopsis)

#include <math.h>

double cbrt(double x); float cbrtf(float x); long double cbrtl(long double x);

Описание (Description)

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.1‐2017 defers to the ISO C standard.

These functions shall compute the real cube root of their argument x.

Возвращаемое значение (Return value)

Upon successful completion, these functions shall return the cube root of x.

If x is NaN, a NaN shall be returned.

If x is ±0 or ±Inf, x shall be returned.

Ошибки (Error)

No errors are defined.

The following sections are informative.

Примеры (Examples)

None.

Использование в приложениях (Application usage)

None.

Обоснование (Rationale)

For some applications, a true cube root function, which returns negative results for negative arguments, is more appropriate than pow(x, 1.0/3.0), which returns a NaN for x less than 0.

Будущие направления (Future directions)