Final answer:
The function pow(x, y) requires the header file 'cmath'. (option d)
Step-by-step explanation:
The 'pow(x, y)' function is a fundamental mathematical function in C++ that computes the value of x raised to the power of y. This function is essential for performing exponentiation operations, allowing programmers to calculate complex mathematical expressions involving powers. To utilize the pow function in a C++ program, including the appropriate header file is imperative for the compiler to recognize and interpret the function correctly.
The 'cmath' header file is specifically designed to provide declarations for mathematical functions in C++, and it encompasses a wide range of mathematical operations, including power calculations. By including '#include <cmath>' at the beginning of a C++ program, developers ensure that the compiler has access to the necessary declarations and definitions for the pow function.
Understanding the role of header files and selecting the correct one is essential for writing efficient and error-free code. In the context of the 'pow(x, y)' function, the 'cmath' header file serves as the bridge between the programmer's code and the underlying mathematical functionalities provided by the C++ Standard Library.