Write function d2x() that takes as input a nonnegative integer n (in the standard decimal representation) and an integer x between 2 and 9 and returns a string of digits that represents the base-x representation of n.

4. what is the reason for including the following code snippet in the header file animal.h? #ifndef animal_h #define animal_h class animal { public: animal(); animal(double new_area_hunt); void birth(); void hunt(double new_area_hunt); void death(); double get_area_hunt() const; private: double area_hunt; }; #endif