pow - power function
cc [ flag ... ] file ... -lm [ library ... ]
double pow(double x, double y);
The pow() function computes the value of x raised to the
power y, x **y . If x is negative, y must be an integer
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.
If y is 0.0 and x is NaN, NaN is returned.
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 to 0, 0 is
returned and errno may be set to ERANGE.
For exceptional cases, matherr(3M) tabulates the values to
be returned as dictated by Standards other than XPG4.
The pow() function will fail if:
EDOM The value of x is negative and y is non-integral.
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.
The correct value would cause underflow.
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.
See attributes(5) for descriptions of the following attri-
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| MT-Level | MT-Safe |
exp(3M), isnan(3M), matherr(3M), attributes(5), standards(5)
Man(1) output converted with