1. Which of the following header lines are invalid? Why?
(a) float average (float x, float y, float z);
(b) double power (double a, int n – 1)
(c) int product (int m, 10)
(d) double minimum (double x; double y;)
(e) int mul (int x, y)
(f) exchange (int *a, int *b)
(g) void sum (int a, int b, int &c) 13. Enumerate the rules that apply to a function call.
2. Summarize the rules for passing parameters to functions by pointers.
3. What are the rules that govern the passing of arrays to function?
4. State the problems we are likely to encounter when we pass global variables as parameters to functions.
5. Write a function exchange to interchange the values of two variables, say x and y. Illustrate the use of this function, in a calling function. Assume that x and y are defined as global variables.