Syntax
- #include <math.h>
- double pow(double x, double y);
- float powf(float x, float y);
- long double powl(long double x, long double y);
Remarks
- To link with math library use
-lm
with gcc flags.
- A portable program that needs to check for an error from a mathematical function should set
errno
to zero, and make the following call feclearexcept(FE_ALL_EXCEPT);
before calling a mathematical function. Upon return from the mathematical function, if errno
is nonzero, or the following call returns nonzero fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW);
then an error occurred in the mathematical function. Read manpage of math_error for more information.