|POW(3)||Linux Programmer's Manual||POW(3)|
NAMEpow, powf, powl - power functions
double pow(double x , double y );
float powf(float x , float y );
long double powl(long double x , long double y );
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;or cc -std=c99
DESCRIPTIONThe pow() function returns the value of x raised to the power of y.
RETURN VALUEOn success, these functions return the value of x to the power of y.
ERRORSSee math_error(7) for information on how to determine whether an error has occurred when calling these functions.
The following errors can occur:
- Domain error: x is negative, and y is a finite noninteger
- errno is set to EDOM. An invalid floating-point exception ( FE_INVALID) is raised.
- Pole error: x is zero, and y is negative
- errno is set to ERANGE (but see BUGS). A divide-by-zero floating-point exception ( FE_DIVBYZERO) is raised.
- Range error: the result overflows
- errno is set to ERANGE. An overflow floating-point exception ( FE_OVERFLOW) is raised.
- Range error: the result underflows
- errno is set to ERANGE. An underflow floating-point exception ( FE_UNDERFLOW) is raised.
CONFORMING TOC99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD, C89.
BUGSIn glibc 2.9 and earlier, when a pole error occurs, errno is set to EDOM instead of the POSIX-mandated ERANGE. Since version 2.10, glibc does the right thing.
SEE ALSOcbrt(3), cpow(3), sqrt(3)
COLOPHONThis page is part of release 3.53 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/.