pow - power function
#include <math.h> double pow(double x, double y);
The pow() function computes the value of x raised to the power y, xy. If x is negative, y must be an integer value.An application wishing to check for error situations should set errno to 0 before calling pow(). If errno is non-zero on return, or the return value is NaN, an error has occurred.
Upon successful completion, pow() returns the value of x raised to the power y.If x is 0 and y is 0, 1.0 is returned.
If y is NaN, or y is non-zero and x is NaN, NaN is returned and errno may be set to [EDOM]. If y is 0.0 and x is NaN, either 1.0 is returned, or NaN is returned and errno may be set to [EDOM].
If x is 0.0 and y is negative, -HUGE_VAL is returned and errno may be set to [EDOM] or [ERANGE].
If the correct value would cause overflow, ±HUGE_VAL is returned, and errno is set to [ERANGE].
If the correct value would cause underflow, 0 is returned and errno may be set to [ERANGE].
The pow() function will fail if:
- [EDOM]
- The value of x is negative and y is non-integral.
- [ERANGE]
- The value to be returned would have caused overflow.
The pow() function may fail if:
- [EDOM]
- The value of x is 0.0 and y is negative, or y is NaN.
- [ERANGE]
- The correct value would cause underflow.
No other errors will occur.
None.
None.
None.
exp(), isnan(), <math.h>.
Derived from Issue 1 of the SVID.