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## NAME

```       pow, powf, powl - power functions

```

## SYNOPSIS

```       #include <math.h>

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)):

powf(), powl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 ||
_ISOC99_SOURCE; or cc -std=c99

```

## DESCRIPTION

```       The pow() function returns the value of x raised to the power of y.

```

## RETURNVALUE

```       On success, these functions return the value of x to the power of y.

If x is a finite value less than 0, and y is  a  finite  noninteger,  a
domain error occurs, and a NaN is returned.

If the result overflows, a range error occurs, and the functions return
HUGE_VAL,   HUGE_VALF,   or   HUGE_VALL,   respectively,    with    the
mathematically correct sign.

If  result  underflows, and is not representable, a range error occurs,
and 0.0 is returned.

Except as specified below, if x or y is a NaN, the result is a NaN.

If x is +1, the result is 1.0 (even if y is a NaN).

If y is 0, the result is 1.0 (even if x is a NaN).

If x is +0 (-0), and y is an odd integer greater than 0, the result  is
+0 (-0).

If  x  is 0, and y greater than 0 and not an odd integer, the result is
+0.

If x is -1, and y is positive infinity or negative infinity, the result
is 1.0.

If  the absolute value of x is less than 1, and y is negative infinity,
the result is positive infinity.

If the absolute value of x  is  greater  than  1,  and  y  is  negative
infinity, the result is +0.

If  the absolute value of x is less than 1, and y is positive infinity,
the result is +0.

If the absolute value of x  is  greater  than  1,  and  y  is  positive
infinity, the result is positive infinity.

If  x  is  negative  infinity, and y is an odd integer less than 0, the
result is -0.

If x is negative infinity, and y less than 0 and not  an  odd  integer,
the result is +0.

If  x is negative infinity, and y is an odd integer greater than 0, the
result is negative infinity.

If x is negative infinity, and y greater than 0 and not an odd integer,
the result is positive infinity.

If x is positive infinity, and y less than 0, the result is +0.

If x is positive infinity, and y greater than 0, the result is positive
infinity.

If x is +0 or -0, and y is an odd integer less than  0,  a  pole  error
occurs  and  HUGE_VAL,  HUGE_VALF,  or HUGE_VALL, is returned, with the
same sign as x.

If x is +0 or -0, and y is less than 0 and not an odd integer,  a  pole
error occurs and +HUGE_VAL, +HUGE_VALF, or +HUGE_VALL, is returned.

```

## ERRORS

```       See  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.

```

## CONFORMINGTO

```       C99, POSIX.1-2001.  The variant returning double also conforms to SVr4,
4.3BSD, C89.

```

## BUGS

```       For  a  pole error, errno is set to EDOM; POSIX.1 says it should be set
to ERANGE.

If x is negative, then large negative or positive y values yield a  NaN
as  the  function  result,  with  errno  set  to  EDOM,  and an invalid
(FE_INVALID) floating-point exception.  For example,  with  pow(),  one
sees  this  behavior when the absolute value of y is greater than about
9.223373e18.

In version 2.3.2 and earlier,  when  an  overflow  or  underflow  error
occurs,   glibcâ€™s   pow()  generates  a  bogus  invalid  floating-point
exception  (FE_INVALID)  in  addition  to  the  overflow  or  underflow
exception.

```

```       cbrt(3), cpow(3), sqrt(3)
```       This  page  is  part of release 3.24 of the Linux man-pages project.  A