#include <math.h>float powf(float base, float exp);double pow(double base, double exp); long double powl(long double base, long double exp);
powf( ) and powl( ) were added by C99.
The pow( ) family of functions returns base raised to the exp power (baseexp). A domain error may occur if base is zero and exp is less than or equal to zero. It will also happen if base is negative and exp is not an integer. A range error is possible.
Related functions are exp( ), log( ), and sqrt( ).