10. Define the terms parameter, argument, and function signature. 11. Write function headers (not the bodies) for the following functions: 1) Return a sales commission, given the sales amount and the commission rate. 2) Return a square root of a number 12. Given two function definitions double m(double x, double y) double m(int x, double y) answer the following questions: a. Which of the two functions is invoked for b. Which of the two functions is invoked for c. Which of the two functions is invoked for double z- m(4, 5); double z-m(4, 5.4); double z- m(4.5, 5.4)