double cbrt(doublex);
float cbrtf(floatx);
long double cbrtl(long doublex);

DESCRIPTION

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

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.

ERRORS

No errors are defined.

The following sections are informative.

EXAMPLES

None.

APPLICATION USAGE

None.

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.

FUTURE DIRECTIONS

None.

SEE ALSO

The Base Definitions volume of IEEE Std 1003.1-2001, <math.h>

COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. 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.opengroup.org/unix/online.html .